ケインズの『一般理論』第1章~第15章(対訳)





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John Maynard Keynes (1936)
The General Theory of Employment, Interest and Money

Written: 1935;
Source: The General Theory of Employment, Interest and Money by John Maynard Keynes, Fellow of the King's College, Cambridge, published by Harcourt, Brace and Company, and printed in the U.S.A. by the Polygraphic Company of America, New York;
First Published: Macmillan Cambridge University Press, for Royal Economic Society in 1936;
Transcribed for M.I.A., corrected and formatted by Andy Blunden;
This Edition: marxists.org 2002.

 

“Our criticism of the accepted classical theory of economics has consisted not so much in finding logical flaws in its analysis as in pointing out that its tacit assumptions are seldom or never satisfied, with the result that it cannot solve the economic problems of the actual world.” [Chapter 24]



Preface

まえがき

Book I Introduction

第1巻 序論

Chapter 1: The General Theory

第1章 一般理論

Chapter 2: The Postulates of the Classical Economics

第2章 古典派経済学の公理

Chapter 3: The Principle of Effective Demand

第3章 有効需要の原理

Book II Definitions and Ideas

第2巻 定義と概念

Chapter 4: The Choice of Units

第4章 単位の選択

Chapter 5. Expectation as Determining Output and Employment

第5章 産出高と雇用を決定するものとしての予想

Chapter 6. The Definition of Income, Saving and Investment

第6章 所得と貯蓄と投資の定義

Appendix on User Cost

付録、使用費用について

Chapter 7. The Meaning of Saving and Investment Further Considered

第7章 貯蓄と投資の意味の再考

Book III The Propensity to Consume

第3巻 消費性向

Chapter 8. The Propensity to Consume: I. The Objective Factors

第8章 消費性向 1 客観的要因

Chapter 9. The Propensity to Consume: II. The Subjective Factors

第9章 消費性向 2 主観的要因

Chapter 10. The Marginal Propensity to Consume and the Multiplier

第10章 限界消費性向と乗数

Book IV The Inducement to Invest

第4巻 投資誘引

Chapter 11. The Marginal Efficiency of Capital

第11章 資本の限界効率

Chapter 12. The State of Long-term Expectation

第12章 長期予想の状況

Chapter 13. The General Theory of the Rate of Interest

第13章 利子率についての一般理論

Chapter 14. The Classical Theory of the Rate of Interest

第14章 利子率についての古典的理論

Appendix on the Rate of Interest in Marshall and Ricardo

付録、マーシャルとリカードの利子率について

Chapter 15. The Psychological and Business Incentives to Liquidity

第15章 流動性に対する心理的事業的な誘引

Chapter 16. Sundry Observations on the Nature of Capital

第16章 資本の性格についての多様な観察

Chapter 17. The Essential Properties of Interest and Money

第17章 利子率と貨幣の重要な属性

Chapter 18. The General Theory of Employment Re-stated

第18章 雇用の一般理論再論

Book V Money-Wages and Prices

第5巻 賃金貨幣と価格

Chapter 19. Changes in Money-Wages

第19章 貨幣賃金の変化について

Appendix on Prof. Pigou's “Theory of Unemployment”

付録、ピグー教授の『失業の理論』について

Chapter 20. The Employment Function

第20章 雇用関数

Chapter 21. The Theory of Prices

第21章 物価の理論

Book VI Short Notes Suggested by the General Theory

第6巻 一般理論によって示唆される短いノート

Chapter 22. Notes on the Trade Cycle 

第22章 景気循環についてのノート

Chapter 23. Notes on Merchantilism, the Usury Laws, Stamped Money and Theories of Under-consumption

第23章 重商主義、利子率制限法、スタンプ貨幣、過小消費論についてのノート

Chapter 24: Concluding Notes on the Social Philosophy towards which the General Theory might Lead

第24章 一般理論が指し示す社会哲学についてのノート

“Whilst workers will usually resist a reduction of money-wages, it is not their practice to withdraw their labour whenever there is a rise in the price of wage-goods. It is sometimes said that it would be illogical for labour to resist a reduction of money-wages but not to resist a reduction of real wages. ... Moreover, the contention that the unemployment which characterises a depression is due to a refusal by labour to accept a reduction of money-wages is not clearly supported by the facts. [Chapter 2]

 

Crisis of Keynesian Economics, Geoff Pilling, 1986
Marx and Keynes, Paul Mattick, 1939
Keynes Archive | M.I.A. | Political Economy Archive


John Maynard Keynes
The General Theory of Employment, Interest and Money

Preface

THIS book is chiefly addressed to my fellow economists. I hope that it will be intelligible to others. But its main purpose is to deal with difficult questions of theory, and only in the second place with the applications of this theory to practice. For if orthodox economics is at fault, the error is to be found not in the superstructure, which has been erected with great care for logical consistency, but in a lack of clearness and of generality in the premisses. Thus I cannot achieve my object of persuading economists to re-examine critically certain of their basic assumptions except by a highly abstract argument and also by much controversy. I wish there could have been less of the latter. But I have thought it important, not only to explain my own point of view, but also to show in what respects it departs from the prevailing theory. Those, who are strongly wedded to what I shall call “the classical theory”, will fluctuate, I expect, between a belief that I am quite wrong and a belief that I am saying nothing new. It is for others to determine if either of these or the third alternative is right. My controversial passages are aimed at providing some material for an answer; and I must ask forgiveness if, in the pursuit of sharp distinctions, my controversy is itself too keen. I myself held with conviction for many years the theories which I now attack, and I am not, I think, ignorant of their strong points.

The matters at issue are of an importance which cannot be exaggerated. But, if my explanations are right, it is my fellow economists, not the general public, whom I must first convince. At this stage of the argument the general public, though welcome at the debate, are only eavesdroppers at an attempt by an economist to bring to an issue the deep divergences of opinion between fellow economists which have for the time being almost destroyed the practical influence of economic theory, and will, until they are resolved, continue to do so.

The relation between this book and my Treatise on Money, which I published five years ago, is probably clearer to myself than it will be to others; and what in my own mind is a natural evolution in a line of thought which I have been pursuing for several years, may sometimes strike the reader as a confusing change of view. This difficulty is not made less by certain changes in terminology which I have felt compelled to make. These changes of language I have pointed out in the course of the following pages; but the general relationship between the two books can be expressed briefly as follows. When I began to write my Treatise on Money I was still moving along the traditional lines of regarding the influence of money as something so to speak separate from the general theory of supply and demand. When I finished it, I had made some progress towards pushing monetary theory back to becoming a theory of output as a whole. But my lack of emancipation from preconceived ideas showed itself in what now seems to me to be the outstanding fault of the theoretical parts of that work (namely, Books III and IV), that I failed to deal thoroughly with the effects of changes in the level of output. My so-called “fundamental equations” were an instantaneous picture taken on the assumption of a given output. They attempted to show how, assuming the given output, forces could develop which involved a profit-disequilibrium, and thus required a change in the level of output. But the dynamic development, as distinct from the instantaneous picture, was left incomplete and extremely confused. This book, on the other hand, has evolved into what is primarily a study of the forces which determine changes in the scale of output and employment as a whole; and, whilst it is found that money enters into the economic scheme in an essential and peculiar manner, technical monetary detail falls into the background. A monetary economy, we shall find, is essentially one in which changing views about the future are capable of influencing the quantity of employment and not merely its direction. But our method of analysing the economic behaviour of the present under the influence of changing ideas about the future is one which depends on the interaction of supply and demand, and is in this way linked up with our fundamental theory of value. We are thus led to a more general theory, which includes the classical theory with which we are familiar, as a special case.

The writer of a book such as this, treading along unfamiliar paths, is extremely dependent on criticism and conversation if he is to avoid an undue proportion of mistakes. It is astonishing what foolish things one can temporarily believe if one thinks too long alone, particularly in economics (along with the other moral sciences), where it is often impossible to bring one's ideas to a conclusive test either formal or experimental. In this book, even more perhaps than in writing my Treatise on Money, I have depended on the constant advice and constructive criticism of Mr. R. F. Kahn. There is a great deal in this book which would not have taken the shape it has except at his suggestion. I have also had much help from Mrs. Joan Robinson, Mr. R. G. Hawtrey and Mr. R. F. Harrod, who have read the whole of the proof-sheets. The index has been compiled by Mr. D. M. Bensusan-Butt of King's College, Cambridge.

The composition of this book has been for the author a long struggle of escape, and so must the reading of it be for most readers if the author's assault upon them is to be successful,― a struggle of escape from habitual modes of thought and expression. The ideas which are here expressed so laboriously are extremely simple and should be obvious. The difficulty lies, not in the new ideas, but in escaping from the old ones, which ramify, for those brought up as most of us have been, into every corner of our minds.

J. M. Keynes

December 13, 1935

序文 略

Book I Introduction

第1巻 序論

Chapter 1 The General Theory

第1章 一般的理論

  I HAVE called this book the General Theory of Employment, Interest and Money, placing the emphasis on the prefix general.The object of such a title is to contrast the character of my arguments and conclusions with those of the classical[1] theory of the subject, upon which I was brought up and which dominates the economic thought, both practical and theoretical, of the governing and academic classes of this generation, as it has for a hundred years past.

 私はこの本を「雇用、利子率、貨幣の一般的な理論」と名付けたが、力点は「一般的」という言葉に置いている。このような題名をつけたのは、私の議論と結論の性格が古典派[1]の経済理論の性格と大きく異なることを強調するためである。古典派の理論は私自身それで育ったものであるし、過去百年間と同じように今の世代の政界と学界の人たちの経済的な物の考え方を現実的にも理論的にも支配しているものである。

  I shall argue that the postulates of the classical theory are applicable to a special case only and not to the general case, the situation which it assumes being a limiting point of the possible positions of equilibrium. Moreover, the characteristics of the special case assumed by the classical theory happen not to be those of the economic society which we actually live, with the result that its teaching is misleading and disastrous if we attempt to apply it to the facts of experience.

私はこの古典派理論の公理が適用できるのは一般的な場合ではなく特殊な場合に限られていること、古典派の理論が想定する状況は、起こりうる均衡状況のうちでも極端なものであることを示すつもりである。さらに、古典派理論が想定するこの特殊な状況の様々な特徴は、我々が実際に生きている経済社会の特徴を反映せず、その結果、古典派理論の教えを経験的な事実に当てはめようとするとうまく行かずに失敗してしまうのである。

Author's Footnotes

[1]. “The classical economists” was a name invented by Marx to cover Ricardo and James Mill and their predecessors, that is to say for the founders of the theory which culminated in the Ricardian economics. I have become accustomed, perhaps perpetrating a solecism, to include in “the classical school” the followers of Ricardo, those, that is to say, who adopted and perfected the theory of the Ricardian economics, including (for example) J. S. Mill, Marshall, Edgeworth and Prof. Pigou.

著者注

[1]「古典派経済学者」という名前は、リカードとジェームズ・ミルとその先駆者たちを総称するためにマルクスによって作り出されたもので、リカード経済学に結実する経済理論の創始者たちを言うのである。ただし、私はやり過ぎかもしれないが、リカードの後継者たち、つまり、リカード経済学の理論を応用して完成させた学者たち、例えばJ.S.ミル(=ジェームズ・ミルの子)、マーシャル、エッジワース、ピグー教授などの学者たちも「古典派」に含めるのを常としている。


Chapter 2 The Postulates of the Classical Economics

第2章 古典派経済学の公理

MOST treatises on the theory of value(価値、価格、値段、値) and production are primarily concerned with the distribution of a given volume of employed resources between different uses and with the conditions which, assuming the employment of this quantity of resources, determine their relative rewards and the relative values of their products.[1]

The question, also, of the volume of the available resources, in the sense of the size of the employable population, the extent(広がり) of natural wealth and the accumulated capital equipment, has often been treated descriptively.

価格と生産の理論についての論文のほとんどは、主として、一定量の雇用された資源(=ここでは人的資源)を様々な用途へ配分する仕方と、その量の資源を雇用すると想定する場合に、資源の相対的報酬と生産物の相対的価格を決定する条件に関するものである[1]。

利用可能な資源の量に関する問題もまた、雇用が可能な人口の規模と、天然の富の埋蔵量、資本設備の蓄積量という問題として、限定的に扱われてきたことはある。

But the pure theory of what determines the actual employment of the available resources has seldom been examined in great detail. To say that it has not been examined at all would, of course, be absurd. For every discussion concerning fluctuations(変動) of employment, of which there have been many, has been concerned with it. I mean, not that the topic has been overlooked, but that the fundamental theory underlying it has been deemed so simple and obvious that it has received, at the most, a bare mention.[2]

しかしながら、利用可能な人的資源の実際の雇用を決めるものは何であるかに関する純粋な理論が詳細に検討されたことは殆どない。もちろん一度もないと言えば嘘になる。というのは、雇用の変動に関する議論は沢山あるし、そのいずれにおいてもこの問題は言及されている。私が言いたいのは、この問題がなおざりにされて来たと言うのではなく、この問題の基礎をなす根本原理があまりに単純明快なものと見なされて、せいぜい言及されるだけで終わってきたということである。[2]

I

The classical theory of employment ― supposedly simple and obvious ― has been based. I think, on two fundamental postulates, though practically without discussion, namely:

i. The wage is equal to the marginal product of labour(=労働力の限界生産物)

That is to say, the wage of an employed person is equal to the value which would be lost if employment were to be reduced by one unit (after deducting(差し引く、控除する) any other costs which this reduction of output would avoid); subject, however, to the qualification that the equality may be disturbed, in accordance with certain principles, if competition and markets are imperfect.

第1節

古典派の雇用理論、これまで単純明快だと見なされてきた理論は、私が思うに、ほとんど議論もされずに、次の二つの基本的な公理に基礎づけられている。

第一公理 
「賃金は労働力の限界生産物(=限界生産力)に等しい」(=労働需要の公理)

即ち、被雇用者の賃金(=例えば時給)は、雇用(=労働力。第4章の定義で明らかになるように、雇用とは労働時間を意味する用語であって、雇用人数を意味しない)を1単位減少(=1時間減少)させた場合に失われる価値(=例えば売上)に等しい(この産出量の減少によって不要となる他の経費はあらかじめ差し引かれている)。ただし、この公理には、競争と市場が不完全な場合にはある種の原則に従ってこの等式の成立が妨げられる可能性がある、という但し書きがつく。

ii. The utility of the wage when a given volume of labour is employed is equal to the marginal disutility of that amount of employment.

That is to say, the real wage of an employed person is that which is just sufficient (in the estimation of the employed persons themselves) to induce the volume of labour actually employed to be forthcoming; subject to the qualification that the equality for each individual unit of labour may be disturbed by combination between employable units analogous to the imperfections of competition which qualify the first postulate.

第二公理 
「ある一定の労働力が雇用されているとき、賃金のもたらす効用(=満足=実質賃金)はその雇用(=労働時間数)のもたらす限界不効用(=追加の苦痛)に等しい」(=実質賃金は労働量の限界不効用に等しい、ある賃金による満足は追加の労働時間による苦痛と等しい)(=労働供給の公理。労働は苦痛なもの、賃金 は快いもの)

即ち、ある被雇用者の実質賃金とは、実際に雇用されるべき労働量を供給する気持ちにさせるのに(被雇用者の評価で)ちょうど充分な賃金のことである。ただし、不完全な競争が第一公理を阻害する可能性があるように、この等式は個別の労働単位にとっては、被雇用単位が団結した場合には成立しない可能性があるという但し書きがつく。

Disutility must be here understood to cover every kind of reason which might lead a man, or a body of men, to withhold their labour rather than accept a wage which had to them a utility below a certain minimum.

ここで言う不効用とは、ある人あるいはある団体が、自分たちに最低限以下の効用しかもたらさない賃金を受け入れるよりは、労働力を撤退しようと思わせる可能性のある全ての種類の理由を含んでいると解すべきである。

This postulate is compatible with what may be called 'frictional' unemployment. For a realistic interpretation of it legitimately allows for various inexactnesses of adjustment which stand in the way of continuous full employment:

この公理はいわゆる「摩擦的失業」(=自分に合った仕事をすぐに見つけられないために起きる失業)とは矛盾しない。というのは、現実的に解釈するなら、完全雇用の継続を妨げるさまざまな調整装置の不完全さは、まさにこの公理に含まれるからである。

for example, unemployment due to a temporary want of balance between the relative quantities of specialised resources as a result of miscalculation or intermittent demand; or to time-lags consequent on unforeseen changes; or to the fact that the change-over from one employment to another cannot be effected without a certain delay, so that there will always exist in a non-static society a proportion of resources unemployed 'between jobs'.

それは例えば、一時的に需要がなくなったり見込み違いのために専門職の人材量に偏りが出来た場合の失業であり、予期せぬ変化のためにタイミングが合わなかった場合の失業であり、一つの職から別の職へ変わるにはある程度時間がかかるのは仕方がないという事実による失業である。従って、動的な社会ではある程度の人的資源の転職による失業は必ず存在する。

  In addition to 'frictional' unemployment, the postulate is also compatible with 'voluntary' unemployment due to the refusal or inability of a unit of labour, as a result of legislation or social practices or of combination for collective bargaining or of slow response to change or of mere human obstinacy, to accept a reward corresponding to the value of the product attributable to its marginal productivity.

この公理は「摩擦的失業」だけでなく「自発的失業」とも矛盾しない。「自発的失業」とは、法律や社会慣習、集団交渉のための団結、変化への対応の遅れ、単なる頑固さなどから、労働力の単位が「限界生産力」による製品の価格に応じた報酬の受取を拒否することによる失業である。

But these two categories of 'frictional' unemployment and 'voluntary' unemployment are comprehensive. The classical postulates do not admit of the possibility of the third category, which I shall define below as 'involuntary' unemployment.

ところが、この「摩擦的失業」と「自発的失業」というこの二つの分類が全ての失業なのである。古典派のこの公理には第三の分類の可能性は含まれないのだ。そして、これこそ私が「非自発的失業」として以下で説明していくものである。

Subject to these qualifications, the volume of employed resources is duly determined, according to the classical theory, by the two postulates. The first gives us the demand schedule for employment, the second gives us the supply schedule; and the amount of employment is fixed(決まる) at the point where the utility of the marginal product balances the disutility of the marginal employment.

古典派経済理論によれば、雇用された人的資源の量は、上記のような但し書きがつきながらも、まさにこの二つの公理によって決定される。第一公理は雇用の需要グラフを提供し、第二公理は雇用の供給グラフを提供する。そして雇用労働の量は、「限界生産物の効用」(=需要)と「労働力の限界不効用」(=供給)が均衡する点で決まる。

  It would follow from this that there are only four possible means of increasing employment:

(a) An improvement in organisation or in foresight which diminishes 'frictional' unemployment;

(b) a decrease in the marginal disutility of labour, as expressed by the real wage for which additional labour is available, so as to diminish 'voluntary' unemployment;

(c) an increase in the marginal physical productivity of labour in the wage-goods industries (to use Professor Pigou's convenient term for goods(財、物品) upon the price of which the utility of the money-wage(賃金貨幣=名目賃金) depends);

(d) an increase in the price of non-wage-goods compared with the price of wage-goods, associated with a shift in the expenditure of non-wage-earners from wage-goods to non-wage-goods.

This, to the best of my understanding, is the stance of Professor Pigou's Theory of Unemployment ― the only detailed account of the classical theory of employment which exists.[3]

 このことから雇用を増大させる方法は4つしかないということになる。

(ア)「摩擦的失業」を減らすために予測の進歩と施設の改善。

(イ)「自発的失業」を減らすために、労働力の追加が可能となるような実質賃金によって表わされた「労働力の限界不効用」を減らす(=賃金を下げる)。

(ウ)賃金財(wage-goods=一般消費財、労働者の消費財、資本財と投資財の対語)の製造業における労働力の物理的な限界生産力の上昇(賃金財というピグー教授の便利な言葉を使わせてもらう。名目賃金の効用はその賃金で購入する賃金財の価格によって決まる)。

(エ)非賃金労働者の支出を賃金財から非賃金財(=贅沢品や嗜好品、投資財)に移しながら、賃金財の価格に比べた非賃金財の価格を上昇させる。

これが、私の理解する限りにおける、ピグー教授の『失業理論』の主張であり、この理論だけが現在存在する唯一の古典派による詳細な雇用理論である[3]。

II

  Is it true that the above categories are comprehensive in view of the fact that the population generally is seldom doing as much work as it would like to do on the basis of the current(現行、当期、経常、流通、当座、流動) wage? For, admittedly, more labour would, as a rule, be forthcoming at the existing money-wage if it were demanded.[4]

第2節

現行の賃金のもとで人びとが欲しいだけの仕事を見つけることなど殆ど不可能なのが現実なのに、「摩擦的失業」と「自発的失業」の二つの分類に全ての失業が含まれるなどということが真実だろうか。というのは、需要さえあれば、普通は当然現行の名目賃金のもとでもっと沢山の労働力が供給可能だからである[4]。

The classical school reconcile this phenomenon with their second postulate by arguing that, while the demand for labour at the existing money-wage may be satisfied before everyone willing to work at this wage is employed, this situation is due to an open or tacit agreement amongst workers not to work for less, and that if labour as a whole would agree to a reduction of money-wages more employment would be forthcoming. If this is the case, such unemployment, though apparently involuntary, is not strictly so, and ought to be included under the above category of 'voluntary' unemployment due to the effects of collective bargaining, etc.

古典派はこの現象を第二公理と合わせるために、現行の名目賃金で働く意欲のある人が全員雇われる前にその賃金での労働力の需要が満たされてしまうことがあ るとしても、労働者たちはそれ以下の賃金では働かないという公然あるいは暗黙の了解があるためにこのような状況になるのであり、労働者側がこぞって名目賃金の引き下げに同意すれば、もっと多くの雇用が生まれると言うのである。もしそうだとするなら、そのような失業は「非自発的」に見えるとしても、厳密にはそうではないことになり、団体交渉などの結果である「自発的失業」という上記の分類に含められることになる。

This calls for two observations, the first of which relates to the actual attitude of workers towards real wages and money-wages respectively and is not theoretically fundamental, but the second of which is fundamental.

しかし、これに対しては二つのことを言わなければならない。一つ目は実質賃金と名目賃金のそれぞれに対する労働者の実際の態度に関するもので、理論上はそれほど本質的なことではない。むしろ、その後の、二つ目のほうが本質的である。

Let us assume, for the moment, that labour is not prepared to work for a lower money-wage and that a reduction in the existing level of money-wages would lead, through strikes or otherwise, to a withdrawal from the labour market of labour which is now employed.

いま仮に、労働者側が現行より低い名目賃金では働く気がないと仮定しよう。つまり、現行の名目賃金レベルを引き下げた場合には、労働者側はストライキなどの手段を通じて、現在雇用されている労働力を労働市場から撤退すると仮定しよう。

Does it follow from this that the existing level of real wages accurately measures the marginal disutility of labour? Not necessarily. For, although a reduction in the existing money-wage would lead to a withdrawal of labour, it does not follow that a fall in the value of the existing money-wage in terms of wage-goods would do so, if it were due to a rise in the price of the latter.

このことは(=第二公理が言うように)現行の実質賃金レベルがまさに「労働力の限界不効用」を表していることになるだろうか。必ずしもそうとは言えまい。というのは、現行名目賃金の引き下げが労働力の撤退に至ることはあっても、現行名目賃金を賃金財で測った価値(=実質賃金)が賃金財の価格(=物価)の上 昇によって下落した場合でも労働力の撤退を引き起こすとは言えないからである。

  In other words, it may be the case that within a certain range the demand of labour is for a minimum money-wage and not for a minimum real wage. The classical school have tacitly assumed that this would involve no significant change in their theory. But this is not so. For if the supply of labour is not a function of real wages as its sole variable, their argument breaks down entirely and leaves the question of what the actual employment will be quite indeterminate.[5] They do not seem to have realised that, unless the supply of labour is a function of real wages alone, their supply curve for labour will shift bodily with every movement of prices(物価). Thus their method is tied up with their very special assumptions, and cannot be adapted to deal with the more general case.

言い換えれば、恐らく実情は一定の範囲内で労働者側が求めるのは最低名目賃金の引き上げであって、最低実質賃金の引き上げではないのである。古典派はこのことが自分たちの理論に大きな違いをもたらさないことを暗黙裡に想定している。しかし、名目か実質かには大きな違いがある。というのは、もし労働力の供給が実質賃金をその唯一の変数とする関数でないなら、彼らの理論は完全に破綻してしまい、現実の雇用労働力の到達点はまったく不定になってしまうからである[5]。もし労働力の供給が実際に実質賃金(=物価変動の影響を受けない)のみの関数でないなら、古典派の労働力供給曲線は物価の変動のたびに全体がシフトしてしまうが、そのことを彼らは理解していないと思われる。したがって、彼らの方法は彼ら自身の非常に特殊な想定と結びついているのであり、もっと一般的な場合に応用することは出来ないのである。

Now ordinary experience tells us, beyond doubt, that a situation where labour stipulates (within limits) for a money-wage rather than a real wage, so far from being a mere possibility, is the normal case. Whilst workers will usually resist a reduction of money-wages, it is not their practice to withdraw their labour whenever there is a rise in the price of wage-goods. It is sometimes said that it would be illogical for labour to resist a reduction of money-wages but not to resist a reduction of real wages. For reasons given below (section III), this might not be so illogical as it appears at first; and, as we shall see later, fortunately so. But, whether logical or illogical, experience shows that this is how labour in fact behaves.

ところで、労働者側が要求するのが(限度はあるが)実質賃金ではなく名目賃金であるというのは、単なる可能性であるどころか通常のことである。それは疑いもなく我々は日常体験から明らかである。ふつう労働者側は名目賃金の引き下げには抵抗するが、賃金財の価格が上昇(=実質賃金の低下)するたびに労働力を撤退するようなことはしないものである。労働者側が名目賃金の引き下げに抵抗するのに実質賃金の引き下げに抵抗しないのは不合理だと時々言われる。しかし、このことは以下(次の3節)にあげる理由から、見かけほど不合理ではないかもしれないのである。それどころか、後に見るように、彼らのこの一見不合理な行動が幸いしているのだ。しかしながら、不合理であるか否かに関わらず、労働者側がこのように振舞うことは我々の日頃の経験から明らかである。

Moreover, the contention that the unemployment which characterises a depression is due to a refusal by labour to accept a reduction of money-wages is not clearly supported by the facts. It is not very plausible to assert that unemployment in the United States in 1932 was due either to labour obstinately refusing to accept a reduction of money-wages or to its obstinately demanding a real wage beyond what the productivity of the economic machine was capable of furnishing. Wide variations are experienced in the volume of employment without any apparent change either in the minimum real demands of labour or in its productivity. Labour is not more truculent in the depression than in the boom ― far from it. Nor is its physical productivity less. These facts from experience are a prima facie(明らかな) ground for questioning the adequacy of the classical analysis.

さらに、不況の特徴である失業の原因は労働者側が名目賃金の引き下げを受け入れないことにあるとする主張はそれほど明確な事実の裏付けをもっているとは言えない。1932年の米国に見られた失業の原因は、労働者側が名目賃金の引き下げを頑固に拒否したからであるとか、経済マシーンの生産性が提供できる以上の実質賃金を頑固に要求したからであるという主張はもっともらしくない。我々は雇用量の大幅な変動を経験したが、その間、労働者側が要求する最低実質賃金にも労働生産性にも明らかな変化はなかったのである。不況の時の労働者側は好況の時ほど戦闘的ではない。むしろ大人しいほどだ。また物理的な生産性も低下はしないものである。経験から得たこのような事実は、古典派の分析の妥当性を疑う明白な根拠となる。

  It would be interesting to see the results of a statistical enquiry into the actual relationship between changes in money-wages and changes in real wages. In the case of a change peculiar to a particular industry one would expect the change in real wages to be in the same direction as the change in money-wages. But in the case of changes in the general level of wages, it will be found, I think, that the change in real wages associated with a change in money-wages, so far from being usually in the same direction, is almost always in the opposite direction. When money-wages are rising, that is to say, it will be found that real wages are falling; and when money-wages are falling, real wages are rising. This is because, in the short period, falling money-wages and rising real wages are each, for independent reasons, likely to accompany decreasing employment; labour being readier to accept wage-cuts when employment is falling off, yet real wages inevitably rising in the same circumstances on account of the increasing marginal return to a given capital equipment when output is diminished.

ここで名目賃金の変動と実質賃金の変動との関係の統計的調査結果を見ると面白いかもしれない。個別の産業に特有の賃金変動の場合には、実質賃金の変化と名目賃金の変化は同じ方向に向かうことが予想される。しかし、全般的な賃金レベルの変動の場合には、名目賃金の変化にともなう実質賃金の変化は通常同じ方向に向かうどころか殆ど常に逆方向に向かうのが見出されるはずだ。つまり、名目賃金が上昇するときには実質賃金が下落しているのが見られ、名目賃金が下落するときには実質賃金が上昇しているのが見られるだろう。これは何故かというと、短期では、名目賃金の低下と実質賃金の上昇はそれぞれ独自の理由で失業の増加を伴って起きるからである。つまり、失業が増加すれば労働者側は賃金カット(=名目賃金の下落)を受け入れやすくなるが、同じ状況において、産出量が低下すると現状の資本設備に対する「限界収益」が上昇する(=収益逓減の法則の逆)ため、実質賃金は必然的に上昇するのである。

  If, indeed, it were true that the existing real wage is a minimum below which more labour than is now employed will not be forthcoming in any circumstances, involuntary unemployment, apart from frictional unemployment, would be non-existent. But to suppose that this is invariably the case would be absurd. For more labour than is at present employed is usually available at the existing money-wage, even though the price of wage-goods is rising and, consequently, the real wage falling. If this is true, the wage-goods equivalent of the existing money-wage is not an accurate indication of the marginal disutility of labour, and the second postulate does not hold good.

確かに、もし現行の実質賃金は、それ以下では今より多くの労働力が供給されることは全くない最低レベルのものだ(=第二公理)というのが本当ならば、「摩擦的失業」以外には「非自発的失業」はありえないことになる。しかし、実質賃金が最低レベルであればいつもこうだと考えるのはおかしい。たとえ賃金財の価格(=物価)が上昇してその結果実質賃金が下落しても、現在雇われているよりも多くの労働力が現行名目賃金で供給可能なことはよくあるからである。そして、もしこれが事実なら、現行名目賃金に相当する賃金財(=実質賃金)は、「労働力の限界不効用」を正確に表していないことになり、第二公理は有効性を失う。

But there is a more fundamental objection. The second postulate flows from the idea that the real wages of labour depend on the wage bargains which labour makes with the entrepreneurs. It is admitted, of course, that the bargains are actually made in terms of money(名目の), and even that the real wages acceptable to labour are not altogether independent of what the corresponding money-wage happens to be. Nevertheless it is the money-wage thus arrived at which is held to determine the real wage. Thus the classical theory assumes that it is always open to labour to reduce its real wage by accepting a reduction in its money-wage. The postulate that there is a tendency for the real wage to come to equality with the marginal disutility of labour clearly presumes that labour itself is in a position to decide the real wage for which it works, though not the quantity of employment(雇用量) forthcoming at this wage.

しかし、もっと根本的反論がある。第二公理は、実質賃金は労働者側が企業家との間で行う賃金交渉によって決まるという考え方から来ている。もちろん、確かに、この交渉が実際に名目賃金について行われたものであっても、労働者側が受け入れ可能な実質賃金がそれに対応する名目賃金と全然無関係ということはない。それでもこうして決められるのは名目賃金であって、それが実質賃金を決めると考えられているのだ。つまり、古典派の理論では、労働者側は名目賃金の引き下げを受け入れることでいつでも自由に実質賃金を引き下げることができると考えられているのである。実質賃金は「労働力の限界不効用」と等しくなる傾向があるとする公理には、あきらかに、労働者側が自分たちの仕事に対する実質賃金を決める立場にあるとする想定があるのだ。もっとも、その実質賃金で生まれる雇用量を労働者側が決めることは出来ないが。

The traditional theory maintains, in short, that the wage bargains between the entrepreneurs and the workers determine the real wage; so that, assuming free competition amongst employers(使用者) and no restrictive combination amongst workers, the latter can, if they wish, bring their real wages into conformity with the marginal disutility of the amount of employment(=労働量) offered by the employers at that wage. If this is not true, then there is no longer any reason to expect a tendency towards equality between the real wage and the marginal disutility of labour.

要するに、伝統的理論は、企業家と労働者たちの間の賃金交渉が決めるのは実質賃金であると主張する。そして、使用者間の自由な競争が維持され、労働者たちの団結に妨害されなければ、労働者たちは望みさえすれば、自分たちの実質賃金を、その賃金のもとで使用者が提供する雇用量の限界不効用に一致させることが出来るというのである。もし労働者にこれが出来ないなら、その場合には、実質賃金と労働力の限界不効用が一致する傾向を予想するどんな理由もなくなってしまうのである。

The classical conclusions are intended, it must be remembered, to apply to the whole body of labour and do not mean merely that a single individual can get employment by accepting a cut in money-wages which his fellows refuse. They are supposed to be equally applicable to a closed system as to an open system, and are not dependent on the characteristics of an open system or on the effects of a reduction of money-wages in a single country on its foreign trade, which lie, of course, entirely outside the field of this discussion. Nor are they based on indirect effects due to a lower wages-bill(賃金費用の総額、企業が被雇用者に支払う全金額) in terms of money(名目の) having certain reactions on the banking system and the state of credit(銀行の貸出状況、信用の状態), effects which we shall examine in detail in Chapter 19. They are based on the belief that in a closed system a reduction in the general level of money-wages will be accompanied, at any rate in the short period and subject only to minor qualifications, by some, though not always a proportionate, reduction in real wages.

ここで忘れてならないのは、古典派理論の様々な結論は労働者側の全体に当てはまるとされており、単に仲間が拒否する名目賃金の引き下げを誰かある個人が受け入れたら雇用されると言っているのではないということである。しかも古典派の理論は、閉鎖経済だけでなく開放経済にも同じように当てはまるものであり、我々の議論からは埒外の開放経済の特質や、ある国の名目賃金の引き下げがその海外貿易に及ぼす効果などに左右されものではないというのである。また、古典派の結論は、名目の賃金費用の総額が減少した場合に銀行や金融市場に与える影響に起因する間接的な効果にも左右されるものでもない。この効果については19章で詳しく検討するだろう。古典派の結論は、閉鎖経済においては、全般的な名目賃金レベルの引き下げがあったときには、少なくとも短期においてわずかの条件さえ整えば、それと同時に実質賃金も、同程度ではないとしても、いくらかは下がるはずだという信念に基づいているのである。

Now the assumption that the general level of real wages depends on the money-wage bargains between the employers and the workers is not obviously true. Indeed it is strange that so little attempt should have been made to prove or to refute it. For it is far from being consistent with the general tenor of the classical theory, which has taught us to believe that prices(物価、価格) are governed by marginal prime-cost(主要費用=要素費用+使用費用=直接費=可変費用) in terms of money and that money-wages largely govern marginal prime-cost. Thus if money-wages change, one would have expected the classical school to argue that prices would change in almost the same proportion, leaving the real wage and the level of unemployment practically the same as before, any small gain or loss to labour being at the expense or profit of other elements of marginal cost(限界費用) which have been left unaltered.[6]

ところで、全般的な実質賃金レベルが使用者と労働者たちの間の名目賃金の交渉によって決まるという想定は、明白な事実ではない。実際、不思議なことに、この想定の証明も反証も殆ど行われたことがないのである。というのは、この想定は、商品の価格は名目の限界主要費用(=主要費用はここが初出、元々マーシャルの用語で主要費用と補足費用で「総費用」になる。「価格は限界費用に等しい」)によって決まり、限界主要費用は主として名目賃金によって決まると我々に信じこませてきた古典派理論の全体的な趣旨とまったく一致しないからである。この趣旨によれば、もし名目賃金に変更があれば、殆ど同じ割合で商品の価格も変化するから、実質賃金と失業率は以前と殆ど変わることはなく(=貨幣数量説)、労働者の多少の得失はこれまで変わることのなかった限界費用(=価格)の他の要素の損得と相殺されると、古典派の学者たちなら主張するだろうと誰もが予想するはずである[6]。

They seem, however, to have been diverted from this line of thought, partly by the settled conviction that labour is in a position to determine its own real wage and partly, perhaps, by preoccupation with the idea that prices depend on the quantity of money. And the belief in the proposition that labour is always in a position to determine its own real wage, once adopted, has been maintained by its being confused with the proposition that labour is always in a position to determine what real wage shall correspond to full employment, i.e. the maximum quantity of employment which is compatible with a given real wage.

ところが、彼らはこの考え方の方向から逸脱してしまったように思われる。それは一方では労働者側は常に自分たちの実質賃金を決定できる立場にあるとの固い信念のためであり、また一方では物価は貨幣量によって決まるという固定観念のためである。そして、労働者が常に自分の実質賃金を決定できるという考え方が信じられて捨てられなかったのは、この考え方と、労働者側が常に完全雇用(つまり実質賃金と両立する雇用の最大値)に対応する実質賃金を決められるとする考え方とを混同したからである。
 
To sum up: there are two objections to the second postulate of the classical theory. The first relates to the actual behaviour of labour. A fall in real wages due to a rise in prices, with money-wages unaltered, does not, as a rule, cause the supply of available labour on offer at the current wage to fall below the amount actually employed prior to the rise of prices. To suppose that it does is to suppose that all those who are now unemployed though willing to work at the current wage will withdraw the offer of their labour in the event of even a small rise in the cost of living. Yet this strange supposition apparently underlies Professor Pigou's Theory of Unemployment,[7] and it is what all members of the orthodox school are tacitly assuming.

以上まとめると、古典派の第二公理に対しては二つの反論がある。第一は、労働者側の実際の行動に関するものである。名目賃金が変わらない状況で物価上昇に よって実質賃金が下がっても、基本的に、現行賃金のもとで供給されている労働力が物価上昇以前の雇用量より下がることはない。それなのに、物価の上昇で労働供給が下がると考えるのは、労働意欲があるのに現行賃金で雇用されていない人は物価が少し上がっても労働力を供給する意思を撤回すると考えるのと同じである。しかしながら、この奇妙な考え方がピグー教授の『失業理論』の根底に横たわっているようである。[7]。そしてこのことは伝統学派の全ての仲間が暗黙のうちに想定していることである。

But the other, more fundamental, objection, which we shall develop in the ensuing chapters, flows from our disputing the assumption that the general level of real wages is directly determined by the character(人物) of the wage bargain. In assuming that the wage bargain determines the real wage the classical school have slipt(<slip)in an illicit assumption. For there may be no method available to labour as a whole whereby it can bring the general level of money-wages into conformity with the marginal disutility of the current volume of employment. There may exist no expedient by which labour as a whole can reduce its real wage to a given figure by making revised money bargains with the entrepreneurs. This will be our contention. We shall endeavour to show that primarily it is certain other forces which determine the general level of real wages. The attempt to elucidate this problem will be one of our main themes. We shall argue that there has been a fundamental misunderstanding of how in this respect the economy in which we live actually works.

しかし、もう一つのもっと重要な反論は、以下の章でもっと詳しく扱うが、全般的な実質賃金レベルが賃金交渉の当事者によって直接決定されるという想定に対するものである。賃金交渉によって実質賃金が決まるという古典派の想定は間違っている。というのは、全体として労働者側が名目賃金の全般的なレベルを現行の雇用量の「限界不効用」に一致させる方法など存在しないからである。いやそもそも、企業家との賃金交渉を作り変えて全体として労働者側が実質賃金を特定の値まで減らせるような都合のいい方法はないのである。これが我々の主張である。我々は全般的な実質賃金レベルを主として決定しているのはもっと別の要因であることを明らかにしようと思う。この問題の解決が我々の主要テーマの一つとなる。我々の現実の生活を支える経済がこの点でどのように機能しているかについて本質的な誤解があると我々は主張していくつもりである。

III

Though the struggle over money-wages between individuals and groups is often believed to determine the general level of real wages, it is, in fact, concerned with a different object.Since there is imperfect mobility of labour, and wages do not tend to an exact equality of net advantage(利益) in different occupations, any individual or group of individuals, who consent to a reduction of money-wages relatively to others, will suffer a relative reduction in real wages, which is a sufficient justification for them to resist it.

第3節

個人の間や団体の間の名目賃金についての争いが全般的な実質賃金レベルを決めている(=実質賃金が高止まりして完全雇用を阻害している)としばしば信じられているが、実際にはそれはもっと別の目的の争いなのである。労働力の流通は不完全であり、賃金は異なる職業の純利益を正確に均等化する方向へは向かわないので、ある個人または団体が名目賃金をほかと比べて相対的に引き下げることに同意すれば、実質賃金も相対的に引き下げることになってしまう。だから、彼らが名目賃金の引き下げを拒否するのは充分正当なことなのである。

 On the other hand it would be impracticable to resist every reduction of real wages, due to a change in the purchasing-power of money which affects all workers alike; and in fact reductions of real wages arising in this way are not, as a rule, resisted unless they proceed to an extreme degree. Moreover, a resistance to reductions in money-wages applying to particular industries does not raise the same insuperable bar to an increase in aggregate employment(総雇用、集計雇用), which would result from a similar resistance to every reduction in real wages.

その一方で、実質賃金の低下(=インフレ)を労働者がいちいち拒否(=賃上げ闘争によって)するのは不可能である。実質賃金の低下は貨幣の購買力の低下によって起こるもので、全労働者に同じように影響するからである。実際、このようにして発生した実質賃金の低下は、それが極端に進行しない限り普通は労働者に受け入れられる。さらに、特定の産業で起きた名目賃金の引き下げに対する抵抗なら、総雇用の増加にはたいした障碍にならないが、もし全ての実質賃金の低下に対して労働者がことごとく抵抗するなら、総雇用の増加への乗り越えがたい障碍となってしまうだろう。

  In other words, the struggle about money-wages primarily affects the distribution of the aggregate(総、集計) real wage between different labour-groups, and not its average amount per unit of employment, which depends, as we shall see, on a different set of forces. The effect of combination on the part of a group of workers is to protect their relative real wage. The general level of real wages depends on the other forces of the economic system.

言い換えれば、名目賃金についての争いは総実質賃金の異なる労働者の団体の間での分配に対して主に影響するが、雇用労働1単位あたりの実質賃金の平均値には影響しないのである。後者は後に見るように別の要因に左右される。労働者グループが団結する効果は、自分たちの相対的な実質賃金を守れることである。全般的な実質賃金レベルは、経済のまた別の要因に左右される。

Thus it is fortunate that the workers, though unconsciously, are instinctively more reasonable economists than the classical school, inasmuch as they resist reductions of money-wages, which are seldom or never of an all-round character(=大幅な、全般的な), even though the existing real equivalent of these wages exceeds the marginal disutility of the existing employment; whereas they do not resist reductions of real wages, which are associated with increases in aggregate employment and leave relative money-wages unchanged, unless the reduction proceeds so far as to threaten a reduction of the real wage below the marginal disutility of the existing volume of employment.

つまり、幸いなことに労働者たちは無意識ではあるが本能的に古典派の学者たちよりも分別のある経済学者なのだ。というのは、たとえ現行の名目賃金の実質的な等価物(=実質賃金)が現行の雇用労働力の「限界不効用」を超えて(=苦痛を補って余りある)いても、彼らは名目賃金のけっして全般的ではない引き下げにも抵抗するが、その一方、実質賃金の低下が進行して現行雇用労働力の「限界不効用」より下回るところまで来ない限り、労働者たちは(=第二公理に反して)実質賃金の低下には抵抗しないので、その結果、相対的な名目賃金は変わらないままで総雇用は増加するのである。

Every trade union will put up some resistance to a cut in money-wages, however small. But since no trade union would dream of striking on every occasion of a rise in the cost of living, they do not raise the obstacle to any increase in aggregate employment which is attributed to them by the classical school.

たとえ少額でも名目賃金のカットに対しては、どの労働組合も抵抗してみせるものである。しかし、物価の上昇(=実質賃金の低下)のたびにストライキを打とうとするような労働組合は存在しない。したがって、古典派の学者は労働組合が(=賃金引下げに抵抗して)総雇用の増加を妨害していると言うが、そんなことはないのである。

IV

We must now define the third category of unemployment, namely 'involuntary' unemployment in the strict sense, the possibility of which the classical theory does not admit.

Clearly we do not mean by 'involuntary' unemployment the mere existence of an unexhausted capacity to work. An eight-hour day does not constitute unemployment because it is not beyond human capacity(人間の能力を超えていない) to work ten hours. Nor should we regard as 'involuntary' unemployment the withdrawal of their labour by a body of workers because they do not choose to work for less than a certain real reward. Furthermore, it will be convenient to exclude 'frictional' unemployment from our definition of 'involuntary' unemployment.

第4節

我々はいまや失業の三つ目の分類、古典派の理論がそんなものはあり得ないと言っている「非自発的失業」の厳密な定義をしなければならない。

我々の言う「非自発的失業」が単なる使いきっていない労働力の存在でないのは明らかである。人間は一日に10時間働く能力があるからといって8時間労働が失業になるわけではないのだ。また、ある労働者の団体が一定の実質所得以下では働きたくないとして労働力を撤回することを「非自発的失業」とみなすべきではない。さらには、「摩擦的失業」を我々の「非自発的失業」の定義から除外するほうが便利だろう。

My definition is, therefore, as follows: Men are involuntarily unemployed if, in the event of a small rise in the price of wage-goods relatively to the money-wage, both the aggregate supply of labour willing to work for the current money-wage and the aggregate demand for it at that wage would be greater than the existing volume of employment. An alternative definition, which amounts, however, to the same thing, will be given in the next chapter (p. 26 below).

すると、私の定義は次のようになる。名目賃金に比べた賃金財価格の少しの上昇(=実質賃金の低下)によって、現行の名目賃金で働く意思のある労働力の総供給(=集計供給、総労働供給)と、その賃金での労働力の総需要(=集計需要、総労働需要)の双方が、ともに当期の雇用労働の量より大きくなっているのに失業している人を「非自発的失業者」というのである(=実質賃金が下がって求人が増えて、名目賃金は同じなので求職は増えているのに、現実には失業している状態を非自発的失業という)。もっとも、次の章では同じことを意味するもう一つの定義(=有効需要不足により失業)が与えられるだろう。

  It follows from this definition that the equality of the real wage to the marginal disutility of employment presupposed by the second postulate, realistically interpreted, corresponds to the absence of 'involuntary' unemployment. This state of affairs we shall describe as 'full' employment, both 'frictional' and 'voluntary' unemployment being consistent with 'full” employment thus defined. This fits in, we shall find, with other characteristics of the classical theory, which is best regarded as a theory of distribution in conditions of full employment.

この定義に従えば、実質賃金は雇用労働力の限界不効用に等しいという第二公理は、現実に当てはめると「非自発的失業」が存在しない状態に対応することになる。この状態を我々は「完全雇用」と呼ぶことにする(■)。このように定義した場合の「完全雇用」は、「摩擦的失業」とも「自発的失業」とも両立するからである。このことは、後に見るように、古典派理論の他の特徴とも符合する。古典派理論は「完全雇用」状態での配分理論と見るのが最善なのである。

So long as the classical postulates hold good, unemployment, which is in the above sense involuntary, cannot occur. Apparent unemployment must, therefore, be the result either of temporary loss of work of the 'between jobs' type or of intermittent demand for highly specialised resources or of the effect of a trade union 'closed shop' on the employment of free labour.

古典派の二つの公理が有効である限りでは、上記の意味での「非自発的失業」は起こりようがない。したがって、見かけ上の失業は、転職による一時的な失業の結果か、高度の専門職の人材に対する需要が一時的になくなったためか、クローズドショップ制(=労働組合員だけが雇用される)が非組合員の雇用に及ぼす影響のせいである。

Thus writers in the classical tradition, overlooking the special assumption underlying their theory, have been driven inevitably to the conclusion, perfectly logical on their assumption, that apparent unemployment (apart from the admitted exceptions) must be due at bottom to a refusal by the unemployed factors to accept a reward which corresponds to their marginal productivity.

こうして、古典的伝統のもとにある学者たちは、自分たちの理論の根底にある特殊な想定(=労働者が賃金交渉で実質賃金を決めているとする想定)を見落としているので、見かけ上の失業の根本的な原因は(自ら認める例外を除いて)雇用されていない生産要素(=失業者)が自分たちの「限界生産力」に合った報酬(=第一公理、労働需要の公理)の受け入れを拒否するからだ(=自発的失業、既出)という、彼らの考えでは完璧に論理的な結論に至らざるを得ないのである。

A classical economist may sympathise with labour in refusing to accept a cut in its money-wage, and he will admit that it may not be wise to make it to meet conditions which are temporary; but scientific integrity forces him to declare that this refusal is, nevertheless, at the bottom of the trouble.

古典派経済学者も、労働者が名目賃金の引き下げを拒否することには同情するし、一時的な条件の変化に名目賃金を合わせることが賢明でないことも認めている。しかし、それにも関わらず、科学者としての潔癖さゆえに彼らは、この労働者の賃下げ拒否こそ問題の根本原因であると表明せざるを得ないのである。

Obviously, however, if the classical theory is only applicable to the case of full employment, it is fallacious to apply it to the problems of involuntary unemployment ― if there be such a thing (and who will deny it?). The classical theorists resemble Euclidean geometers in a non-Euclidean world who, discovering that in experience straight lines apparently parallel often meet, rebuke the lines for not keeping straight as the only remedy for the unfortunate collisions which are occurring. Yet, in truth, there is no remedy except to throw over the axiom of parallels and to work out a non-Euclidean geometry. Something similar is required today in economics. We need to throw over the second postulate of the classical doctrine and to work out the behaviour of a system(=system of a behaviour) in which involuntary unemployment in the strict sense is possible.

しかしながら、もし古典派理論が完全雇用状態にしか適用できないものなら、そしてもし「非自発的失業」が存在するなら(誰がそれを否定するだろうか)、この非自発的失業という問題に古典派理論を適用するのは明らかに間違っている。古典派の学者は非ユークリッド世界のなかのユークリッド幾何学者に似ている。彼らは見かけ上は平行な2直線がしばしば交わることを経験上見出しても、2直線の不幸な交わりが起こるのを正すには線をまっすぐ保つしかないのにそうしないのが悪いと言うのだ。しかし実際には、平行線の公理を捨てて非ユークリッド幾何学を構築するしか解決方法はないのである。同様のことが現在の経済学にも求められている。我々は古典派経済学の第二公理を捨てて、「非自発的失業」が厳密な意味で可能となるような経済行動の体系を構築する必要がある。

V

  In emphasising our point of departure from the classical system, we must not overlook an important point of agreement. For we shall maintain the first postulate as heretofore, subject only to the same qualifications as in the classical theory; and we must pause, for a moment, to consider what this involves.

第5節

我々は古典派の体系からの決別を強調するあまりに、彼らと同意できる重要な点を見過ごすべきではない。というのは、第一公理の方は、これまで同様、古典派理論と同じ但し書きに従うだけで、我々はこれを保持しつづけるからである。しばらく間、我々はこの公理の内容を検討しなくてはならない。

  It means that, with a given organisation, equipment and technique, real wages and the volume of output (and hence of employment) are uniquely(ただ一つの、独自の、一意の) correlated, so that, in general, an increase in employment can only occur to the accompaniment of a decline in the rate of real wages. Thus I am not disputing this vital fact which the classical economists have (rightly) asserted as indefeasible. In a given state of organisation, equipment and technique, the real wage earned by a unit of labour has a unique (inverse) correlation with the volume of employment. Thus if employment increases, then, in the short period, the reward per unit of labour in terms of wage-goods must, in general, decline and profits increase.[8]

この公理(=労働需要の公理)の意味するところは、組織と設備と技術を一定とした場合、実質賃金と産出量(つまり雇用労働の量)は一意的な相関関係にある ので、一般に雇用の増加は実質賃金率の低下に伴ってのみ起こりうる(=右下がりのグラフ)というものである。そして、古典派経済学者が論駁の余地がないとまさに主張するこの枢要な事実に関して、私は異議を唱えるつもりはない。組織と設備と技術を一定とした場合、1単位の労働によって得られる実質賃金は、雇用量と一意の(負の)相関関係(=右下がりのグラフ)にある。つまり、短期においては、雇用が増加すれば、賃金財(=物価)で測った労働1単位あたりの報酬(=実質賃金)は一般に低下して、利潤(=企業家の)は増加するのである。[8]

This is simply the obverse(反面) of the familiar proposition that industry is normally working subject to decreasing returns in the short period during which equipment etc. is assumed to be constant; so that the marginal product in the wage-good industries (which governs real wages) necessarily diminishes as employment is increased. So long, indeed, as this proposition holds, any means of increasing employment must lead at the same time to a diminution of the marginal product and hence of the rate of wages measured in terms of this product.

これは、産業は短期において設備その他を一定とした場合には普通は「収益逓減の法則」に従うとする有名な法則の単なる裏返しである。その結果、雇用労働力が増大するに従って、賃金財産業の「限界生産物」(これが実質賃金を決める)は必然的に減少するのである。事実、この法則が有効な限り、雇用を増やすために何をしようと、それは必ず限界生産物の減少に、ひいては、この生産物によって測った賃金率の低下を招くのである。

But when we have thrown over the second postulate, a decline in employment, although necessarily associated with labour's receiving a wage equal in value to a larger quantity of wage-goods, is not necessarily due to labour's demanding a larger quantity of wage-goods; and a willingness on the part of labour to accept lower money-wages is not necessarily a remedy for unemployment. The theory of wages in relation to employment, to which we are here leading up, cannot be fully elucidated, however, until Chapter 19 and its Appendix have been reached.

しかしながら、もし我々が第二公理(=労働者側は実質賃金を要求して手に入れる)を放棄するなら、より多くの賃金財に匹敵する価値の賃金(=より多くの実質賃金)を労働者が受け取ることに伴って必然的に雇用が減少する(=第一公理)けれども、この減少の原因は必ずしも労働者が賃金財を多く要求したからということにはならない。つまり、労働者がより低い名目賃金を喜んで受け入れることが失業の解決策だとは必ずしも言えないのである。しかしながら、我々がここまで行ってきた賃金と雇用の関係に関する理論の解明はまだ不充分で、その完全な解明は第19章とその付録においてはじめて行われることになる。

VI

From the time of Say and Ricardo the classical economists have taught that supply creates its own demand; meaning by this in some significant, but not clearly defined, sense that the whole of the costs of production must necessarily be spent in the aggregate, directly or indirectly, on purchasing the product.

第6節

セイとリカードの時代から古典派経済学者は、供給が自分自身の需要を作り出すと教えてきた。それは、生産の過程でコストとして(=労働者に)支払った金は全てがことごとくその生産物を直接間接に商品として(=労働者によって)購入される際に必ず使われるという意味だが、何か意味ありげで曖昧さを残している。

  In J. S. Mill's Principles of Political Economy the doctrine is expressly set forth:

What constitutes the means of payment for commodities is simply commodities. Each person's means of paying for the productions of other people consist of those which he himself possesses. All sellers are inevitably, and by the meaning of the word, buyers. Could we suddenly double the productive powers of the country, we should double the supply of commodities in every market; but we should, by the same stroke, double the purchasing power. Everybody would bring a double demand as well as supply; everybody would be able to buy twice as much, because every one would have twice as much to offer in exchange. [Principles of Political Economy, Book III, Chap. xiv. § 2.]

J.S.ミルの『経済学原理』にはこの考え方が明確に述べられている。

商品の支払いのための手段は何かと言えば、それは要するに商品なのである。誰であろうと他人の生産物に対してその人が支払う手段は、自分自身がもっている生産物なのである。全ての売り手は必然的にその言葉の本来の意味において買い手なのである。もし我々が国の生産力を急に2倍にすることが出来たら、全ての市場での商品の供給を2倍にすることが出来る。しかし、それと同時に、我々の購買力も2倍になるのである。誰もが2倍の供給と需要をもたらすのである。誰もが2倍買えるようになるのは、誰もが2倍の商品を提供して交換できるようになるからである。(『経済学原理』第三巻14章2節)

As a corollary of the same doctrine, it has been supposed that any individual act of abstaining from consumption necessarily leads to, and amounts to the same thing as causing the labour and commodities thus released from supplying consumption to be invested in the production of capital wealth. The following passage from Marshall`s Pure Theory of Domestic Values[9] illustrates the traditional approach:

この考え方の帰結として、消費を控える個人的な行為(=貯蓄)は、消費に回すことから解放された労働や商品を必然的に投資に回して資本資産の形成に使うことであり、それはつまり投資と同じことだと考えられているのである。マーシャルの『国内価格の純理論』[9]から引いた次の文章は、この伝統的な考え方を説明している。

The whole of a man's income is expended in the purchase of services and of commodities. It is indeed commonly said that a man spends some portion of his income and saves another. But it is a familiar economic axiom that a man purchases labour and commodities with that portion of his income which he saves just as much as he does with that he is said to spend. He is said to spend when he seeks to obtain present enjoyment from the services and commodities which he purchases. He is said to save when he causes the labour and the commodities which he purchases to be devoted to the production of wealth from which he expects to derive the means of enjoyment in the future.

一人の人間の所得はすべてサービスと商品の購入のために消費される。確かに人は所得の一部を支出し残りを貯蓄すると一般に言われている。しかし、人は支出に回した所得だけで労働と商品を購入するのではなく、貯蓄に回した所得でもそうするというのが、有名な経済的原理である。購入したサービスと商品から現在の楽しみを得ようとする場合に「支出する」と言われるのであり、購入した労働と商品を将来の楽しみが予想される富の形成に振り向ける場合に「貯蓄する」と言われるのである。

  It is true that it would not be easy to quote comparable passages from Marshall's later work[10] or from Edgeworth or Professor Pigou. The doctrine is never stated today in this crude form. Nevertheless it still underlies the whole classical theory, which would collapse without it.

確かにこれと似た文章を最近のマーシャルの著書[10]やエッジワースやピグー教授の本から引用するのは容易ではない。今日ではこの考え方はもはやこれほど生(なま)な形で述べられてはいない。にもかかわらず、この考え方は今でも古典派理論全体の根底をなしており、これがなければ古典派の理論は崩壊してしまうのである。

Contemporary economists, who might hesitate to agree with Mill, do not hesitate to accept conclusions which require Mill's doctrine as their premise. The conviction, which runs, for example, through almost all Professor Pigou's work, that money makes no real difference except frictionally and that the theory of production and employment can be worked out (like Mill's) as being based on 'real' exchanges with money introduced perfunctorily in a later chapter, is the modern version of the classical tradition.

現代の経済学者は、ミルの考え方に同意することに躊躇しても、ミルの考え方を前提としなければ導き出せない様々な結論を受け入れることには躊躇しない。例えばピグー教授の殆ど全ての著作を通じて見られる信念、つまり貨幣はその流れが停滞する時以外には実質的に大きな役割を果たさず(=貨幣の中立性、貨幣は仲介物でしかない)、生産と雇用の理論は現物の交換に基づいて構築することが出来るものであり(ミルの理論のように)、貨幣は適当に後の方で紹介しておけばよいとする信念は、古典派の伝統の現代版といえる。

Contemporary thought is still deeply steeped in the notion that if people do not spend their money in one way they will spend it in another.[11] Post-war economists seldom, indeed, succeed in maintaining this standpoint consistently; for their thought today is too much permeated with the contrary tendency and with facts of experience too obviously inconsistent with their former view.[12] But they have not drawn sufficiently far-reaching consequences; and have not revised their fundamental theory.

現代の考え方も、一つの方面で支出されなかった金は別の方面で支出されるとする考え方に依然としてどっぷりと浸っている[11]。(確かに第一次大戦後の経済学者がこの立場を一貫して維持することに成功しているとは言えない。というのは、彼らの考えは今日ではこれに反対する動きに強く影響されており、自分たちのかつての物の見方とはあまりにも明らかに対立する経験的事実から影響を受けているからである[12]。しかしながら、彼らはここから充分に有意義な結論を引き出したわけではないし、自分たちの基本的な理論を作り直したわけでもない。)

  In the first instance, these conclusions may have been applied to the kind of economy in which we actually live, by false analogy from some kind of non-exchange Robinson Crusoe economy, in which the income which individuals consume or retain as a result of their productive activity is, actually and exclusively, the output in specie(同種のもので) of that activity. But, apart from this, the conclusion that the costs of output are always covered in the aggregate by the sale-proceeds(売上、収益) resulting from demand, has great plausibility, because it is difficult to distinguish it from another, similar-looking proposition which is indubitable, namely that income derived in the aggregate by all the elements in the community concerned in a productive activity necessarily has a value exactly equal to the value of the output.

まず第一に、こうした古典派の様々な結論が、我々が実際に暮らしている経済に適用されてきたのは、ロビンソン・クルーソーの経済のような交換のない経済からの誤った類推によるのかもしれない。そのような経済では、自分の生産活動の結果として個人が消費したり保持したりする所得は、実際のところ、その生産活動による産出物そのものでしかあり得ないからである。しかし、これとは別に、生産にかけた費用は需要に応じた販売の売上によって常にことごとく取り返せるとする結論は、非常にもっともらしいものである。なぜなら、この結論と、これと非常によく似た疑う余地のない法則、つまり、社会の中の生産活動に関わる全ての要素(=労働者)が生み出す所得の合計は、産出物の価格とちょうど一致するという法則との違いを指摘することは難しいからである。

Similarly it is natural to suppose that the act of an individual, by which he enriches himself without apparently taking anything from anyone else, must also enrich the community as a whole; so that (as in the passage just quoted from Marshall) an act of individual saving inevitably leads to a parallel act of investment. For, once more, it is indubitable that the sum of the net increments of the wealth of individuals must be exactly equal to the aggregate net increment of the wealth of the community.

同様にして、ある個人が一見して他人から何も奪うことなく自分の富を増やした場合には、その行為は同時に社会全体の富を増やしているに違いないと考えるの は当然である。つまり(たったいまマーシャルの著書から引用した文章にあるように)、個人が貯蓄を行うことはそのまま投資を行うことに必然的につながっているのである。というのは、繰り返すが、個人の富の純増額が社会の富の純増の合計とちょうど一致するのは疑問の余地がないからである。

Those who think in this way are deceived, nevertheless, by an optical illusion(錯覚), which makes two essentially different activities appear to be the same. They are fallaciously supposing that there is a nexus which unites decisions to abstain from present consumption with decisions to provide for future consumption; whereas the motives which determine the latter are not linked in any simple way with the motives which determine the former.

それにもかかわらず、このような考え方をする人たちは一種の錯覚におちいっている。彼らは二つの本質的に異なる行動を同じ行動であるとみなしているのだ。彼らは、現在の消費を控える決断と将来の消費に備える決断の間には双方を結びつける関連性があると考えているが、それは間違いである。実際には、後者つまり将来の消費に備える決断をする動機は、前者つまり現在の消費を控える決断をする動機と何の繋がりもないのである。

  It is, then, the assumption of equality between the demand price of output as a whole and its supply price, which is to be regarded as the classical theory's 'axiom of parallels'. Granted this, all the rest follows ― the social advantages of private and national thrift, the traditional attitude towards the rate of interest, the classical theory of unemployment, the quantity theory of money, the unqualified advantages of laissez-faire in respect of foreign trade and much else which we shall have to question.

さらに、産出物全体の需要価格(=売上)と供給価格(=費用)が等しい(=総需要価格は総供給価格と等しい)とする想定こそは、古典派経済学の「平行線の公理」と呼ぶべきものである。そしてこの想定を容認したところから、残りの全ての古典派の経済理論が来ているのだ。曰く、民間と政府が節約することの社会的利益、利子率に対する伝統的態度、雇用の古典的理論、貨幣数量説、海外貿易における自由放任主義の無条件な利益、等々。我々はこれらに異議を唱えていくつもりである。

VII

At different points in this chapter we have made the classical theory to depend in succession on the assumptions:

(1) that the real wage is equal to the marginal disutility of the existing employment;

(2) that there is no such thing as involuntary unemployment in the strict sense;

(3) that supply creates its own demand in the sense that the aggregate demand price is equal to the aggregate supply price for all levels of output and employment.

These three assumptions, however, all amount to the same thing in the sense that they all stand and fall together, any one of them logically involving the other two.


第7節

我々はこの章の様々な場所において、古典派の理論が次のような想定に依存してることを次々に見てきた。

(1)実質賃金は現行雇用労働力の限界不効用に等しい。

(2)厳密な意味での「非自発的失業」というものは存在しない。

(3)供給は自分自身の需要を作り出す。つまり、生産と雇用がどの水準にあろうと、総需要価格は総供給価格に等しい。

しかしながら、この三つの想定はすべて同じものを指している。つまり、どれ一つをとっても論理的に他の二つのものを含んでおり、全てが成り立つか全てが成り立たないかのどちらかなのである。

Author's Footnotes

[1]. This is in the Ricardian tradition. For Ricardo expressly repudiated any interest in the amount of the national dividend(国民分配=国民所得の量), as distinct from its distribution(国民所得の配分). In this he was assessing correctly the character of his own theory. But his successors, less clear-sighted, have used the classical theory in discussions concerning the causes of wealth. Vide Ricardo's letter to Malthus of October 9, 1820: “Political Economy(経済学) you think is an enquiry into the nature and causes of wealth ― I think it should be called an enquiry into the laws which determine the division of the produce of industry amongst the classes who concur in its formation. No law can be laid down respecting quantity, but a tolerably correct one can be laid down respecting proportions. Every day I am more satisfied that the former enquiry is vain and delusive, and the latter only the true objects of the science.”

[2]. For example, Prof. Pigou in the Economics of Welfare (4th ed. p. 127) writes (my italics): “Throughout this discussion, except when the contrary is expressly stated, the fact that some resources are generally unemployed against the will of the owners is ignored. This does not affect the substance of the argument, while it simplifies its exposition.”. Thus, whilst Ricardo expressly disclaimed any attempt to deal with the amount of the national dividend as a whole, Prof. Pigou, in a book which is specifically directed to the problem of the national dividend, maintains that the same theory holds when there is some involuntary unemployment as in the case of full employment.

[3]. Prof. Pigou's Theory of Unemployment is examined in more detail in the Appendix to Chapter 19 below.

[4]. Cf. the quotation from Prof. Pigou above, p. 5, footnote.

[5]. This point is dealt with in detail in the Appendix to Chapter 19 below.

[6]. This argument would, indeed, contain, to my thinking, a large element of truth, though the complete results of a change in money-wages are more complex, as we shall show in Chapter 19 below.

[7]. Cf. Chapter 19, Appendix.

[8]. The argument runs as follows: n men are employed, the nth man adds a bushel a day to the harvest, and wages have a buying power of a bushel a day. The n + 1 th man, however, would only add .9 bushel a day, and employment cannot, therefore, rise to n + 1 men unless the price of corn rises relatively to wages until daily wages(日給) have a buying power of .9 bushel. Aggregate wages would then amount to 9/10 (n + 1) bushels as compared with n bushels previously. Thus the employment of an additional man will, if it occurs, necessarily involve a transfer of income from those previously in work to the entrepreneurs.

[9]. p. 34.

[10]. Mr. J. A. Hobson, after quoting in his Physiology of Industry (p. 102) the above passage from Mill, points out that Marshall commented as follows on this passage as early as his Economics of Industry, p. 154. “But though men have the power to purchase, they may not choose to use it.” “But”, Mr Hobson continues, “he fails to grasp the critical importance of this fact, and appears to limit its action to periods of 'crisis'.” This has remained fair comment, I think, in the light of Marshall's later work.

[11]. Cf. Alfred and Mary Marshall, Economics of Industry, p. 17: “It is not good for trade to have dresses made of material which wears out quickly. For if people did not spend their means on buying new dresses they would spend them on giving employment to labour in some other way.” The reader will notice that I am again quoting from the earlier Marshall. The Marshall of the Principles had become sufficiently doubtful to be very cautious and evasive. But the old ideas were never repudiated or rooted out of the basic assumptions of his thought.

[12].. It is this distinction of Prof. Robbins that he, almost alone, continues to maintain a consistent scheme of thought, his practical recommendations belonging to the same system as his theory.

著者注

[1] これはリカード派の伝統である。リカードは国民分配分(=国民所得)の分配はともかく、国民分配分の量に対する関心はないと言っている。この点で彼は自分の理論の性格を正しく理解している。しかし、彼ほど賢明ではない彼の後継者たちは古典派の理論を富の源泉についての議論に利用してきた。リカードがマルサスに宛てた1820年10月9日の手紙を参照せよ。「あなたは経済学を富の性格と源泉についての研究だと考えている。私は経済学を、産業生産物をその製造に関わる階級の間でどのように分配するかを決める法則についての研究だと見るべきだと思っている。量に関してはどんな法則も決めることもできないが、割合に関する法則ならかなり正確なものを定めることが出来る。私は前者の研究は無意味な出鱈目なものであり、後者だけが科学の真の対象であるとする確信を日々深めている」

[2] 例えば、ピグー教授はその著「厚生経済学」(第4版127頁)の中で「一部の人的資源が全体的に不本意ながら雇用されないでいるという事実は、特に言及しない限り、この議論の間じゅう無視されている。これによって話が単純化される一方で、これによって議論の本質が影響を受けることはないからである」と言っている。リカードが全体としての国民分配分(=国民所得)の量を扱うことに明確に反対したのに対して、ピグー教授は国民分配分の問題を専門的に扱った著書の中で、このように「非自発的失業」がある場合も「完全雇用」の状態と同じ理論が有効だと主張しているのである。

[3] ピグー教授の『失業理論』については19章の付録でさらに詳細な検討を加えた。

[4] 上記注のピグー教授からの引用参照。

[5] この点は第19章の付録で詳しく論じている。

[6] 私の考えでは、この議論は多くの事実を含んでいる。ただし第19章で見るとおり、名目賃金の変化がもたらす全ての結果はもっと複雑である。

[7] 第19章の付録を参照。

[8] これは具体的には次のようになる。いま農作業にN人の人が雇われていて、N番目に雇われた人は1日1ブッシェルを収穫しており、1日1ブッシェル買える賃金(=実質賃金)をもらっているとする。しかしながら、そこへN+1番目の人が雇われても収穫は1日0.9ブッシェルしか増えないはずである(=限界生産力逓減の法則)。したがって、小麦の価格が上昇して1日の日当で0.9ブッシェルしか買えなくなるときに(=実質賃金が0.9ブッシェルに下がったとき限界生産力と実質賃金が一致)はじめて雇用労働力はN+1人に増えることができる(=失業率の低下は物価の上昇を伴う)。そのときの総賃金(=実質賃金)は以前のNブッシェルから0.9×(N+1)ブッシェルになる。こうして、追加の1人の雇用は、元から働いている人達から企業家への所得の移転が必ず伴うのである(=元からいる人の実質賃金は下がる)。

[9] 34ページ

[10] J.A.ホブソンは『産業の生理学』(102頁)に上記のミルの文章を引用してから、マーシャルが自らの『産業の経済学』の154頁で早くからこのミルの文章について次のようにコメントしているのを紹介している。「人びとは購買力をもっていてもそれを使うとは限らない」。それに対してホブソンは「しかしマーシャルはこの事実(=金を使わないことがある事)の決定的な重要性を把握せず、購買力を使わない行為を「危機」の期間に限定しているようだ」と書いた。この意見はマーシャルの後の作品を見ても正しいと思う。

[11] アルフレッド&メアリー・マーシャルの『産業の経済学』17頁参照。「すぐに擦り切れる服地で洋服を作るのはうまい商売の仕方ではない。たとえ(=丈夫な服地のせいで)人びとが新しい洋服を買うためにお金を使わなくなっても、別の方法でお金を使って労働者の仕事をつくるからである」。読者は、私がまたもや初期のマーシャルから引用していることにお気づきだろう。のちの『経済原理』を書いた頃のマーシャルは充分懐疑的になっておりもっと慎重で曖昧な書き方をしている。しかし、彼は自分の思想の基盤となって様々な想定の中から、昔のこの考え方を決して捨て去りはしなかったのである。

[12] ロビンズ教授は殆どただ一人、一貫して思考の骨格を維持し続けており、彼の実践的提言は自身の理論と同じ方法論から来ているが、これは彼のこの非凡さゆえである。


Chapter 3. The Principle of Effective Demand

第3章 有効需要の原理

I

  WE need, to start with, a few terms which will be defined precisely later. In a given state of technique, resources and costs, the employment of a given volume of labour by an entrepreneur involves him in two kinds of expense: first of all, the amounts which he pays out to the factors of production (exclusive of other entrepreneurs) for their current services, which we shall call the factor cost(要素費用) of the employment in question; and secondly, the amounts which he pays out to other entrepreneurs for what he has to purchase from them together with the sacrifice(犠牲、出費、支出、contributeの裏返しの言葉、使用) which he incurs by employing the equipment instead of leaving it idle, which we shall call the user cost(=使用費用) of the employment in question.[1]

第1節

 我々はまず若干の専門用語から始めなければならない(用語の正確な定義は後に行う)。一定の技術と資源と経費のもとで企業家が一定量の労働者を雇用するた めには2種類の経費が必要である。その第一は、生産要素(ほかの企業家を除く)がもたらす当期のサービスに対して支払う金額で、これを当該雇用にかかる「要素費用」(=賃金)と呼ぶことにする。その第二は、ほかの企業家から購入するものについてその企業家に支払う金額(=原材料費)で、設備を止めずに稼働させ続けるために必要な出費(=可変的減価償却費)をそれに加えて、当該雇用にかかる「使用費用(=原材料費+可変的減価償却費)」(=userのerは「反復」を表すから「使用者費用」は誤訳と伊東光晴の『現代経済学事典』、設備を動かすのに必要な費用、可変費用)と呼ぶことにする[1]。

The excess of(A over B で AがBを上回る分、つまりAからBを引いた余り) the value of the resulting output over the sum of its factor cost and its user cost is the profit or, as we shall call it, the income of the entrepreneur. The factor cost is, of course, the same thing, looked at from the point of view of the entrepreneur, as what the factors of production regard as their income.

その経費の結果である産出物の価格(=後のA)が要素費用(=後のF)と使用費用(=後のU)の合計(=主要費用)を上回る額が「企業家の利潤」(=A-U-F)であるが、それを我々は「企業家の所得」と呼ぶこともある。要素費用とは企業家の目から見たもので、もちろん生産要素(=労働者)が自分たちの所得とみなしているものと同じである。
 
Thus the factor cost and the entrepreneur's profit make up, between them, what we shall define as the total income resulting from the employment given by the entrepreneur. The entrepreneur's profit thus defined is, as it should be, the quantity which he endeavours to maximise when he is deciding what amount of employment(=労働量) to offer. It is sometimes convenient, when we are looking at it from the entrepreneur's standpoint, to call the aggregate income (i.e. factor cost plus profit) resulting from a given amount of employment the proceeds of that employment. On the other hand, the aggregate supply price [2] of the output of a given amount of employment is the expectation(予想、見込み) of proceeds which will just make it worth the while of the entrepreneurs to give that employment.[3]

そして、「要素費用」と「企業家の利潤」の二つを合わせたものを「総所得」と呼ぶことにする。総所得は企業家が雇用を提供した結果生まれるものである。当然ながら、企業家はどれだけの雇用を提供するか決めるときに、上で定義した「企業家の利潤」が最大になるように努力する。だから、時には、企業家の観点から見て、一定の雇用量から生まれる「総所得(即ち要素費用+企業家の利潤)」をその「雇用の売上」と呼ぶのが便利である。逆に言えば、ある雇用量が生み出す産出物の総供給価格(=後のZ、総費用)[2]とは、企業家が将来もその雇用量を提供する費用をまかなう売上の予想値である[3]。

  It follows that in a given situation of technique, resources and factor cost per unit of employment, the amount of employment, both in each individual firm and industry and in the aggregate, depends on the amount of the proceeds which the entrepreneurs expect to receive from the corresponding output.[4] For entrepreneurs will endeavour to fix(決める) the amount of employment at the level which they expect to maximise the excess of the proceeds over the factor cost.

つまり、技術と資源と雇用1単位あたりの要素費用が一定の場合には、個別の企業や産業においても全体の企業や産業においても、雇用量は、それに対応する産出物の売上に対する予想値に基づいて決まるのである[4]。というのは、企業家は売上が要素費用を上回る額が最大になると予想するレベルに雇用量を合わせようと努めるからである。

Let Z be the aggregate supply price of the output from employing N men, the relationship between Z and N being written Z = φ(N), which can be called the Aggregate Supply Function.[5] Similarly, let D be the proceeds which entrepreneurs expect to receive from the employment of N men, the relationship between D and N being written D = f(N), which can be called the Aggregate Demand Function.

N人の雇用から生まれる産出物の総供給価格(=総費用)をZとし、ZとNの関係を Z =φ(N)と書くと、これは「総供給関数」(=費用の関数)と呼ぶことが出来る[5]。同様にして、N人の雇用から生まれる売上の予想値をDとし、DとNの関係をD = f(N)と書くと、これは「総需要関数」(=売上の関数)と呼ぶことが出来る。

Now if for a given value of N the expected proceeds are greater than the aggregate supply price, i.e. if D is greater than Z, there will be an incentive(インセンティブ、誘引) to entrepreneurs to increase employment beyond N and, if necessary, to raise costs by competing with one another for the factors of production, up to the value of N for which Z has become equal to D.

そこで、もしある数Nに対する売上の予想値(=D)が総供給価格(=Z)より大きい場合、即ちDがZより大きい場合には、雇用をNより大きくしたいというインセンティブが企業家たちに生まれる。そして必要があれば、企業家たちは互いに競いあってZがDと等しくなるようなNの値になるまで、生産要素を獲得するために費用を増やそうとする気持ちになるのである。

Thus the volume of employment is given by the point of intersection between the aggregate demand function and the aggregate supply function; for it is at this point that the entrepreneurs' expectation of profits will be maximised. The value of D at the point of the aggregate demand function, where it is intersected by the aggregate supply function, will be called the effective demand(有効需要). Since this is the substance of the General Theory of Employment, which it will be our object to expound, the succeeding chapters will be largely occupied with examining the various factors upon which these two functions depend.

このようにして雇用量は、総需要関数と総供給関数が交わる点によって与えられる。というのは、企業家の利潤の予想値が最大になるのは、この点においてだからである。総需要関数が総供給関数と交わる点におけるDの値を「有効需要」(=実際の売上)と呼ぶことにする。これが「雇用の一般的理論」の本質であり、これを詳しく説明することが我々の目標なので、以降の章ではこの二つの関数が依存する様々な要素について詳しく検討していくことになる。

The classical doctrine, on the other hand, which used to be expressed categorically in the statement that “Supply creates its own Demand” and continues to underlie all orthodox economic theory, involves a special assumption as to the relationship between these two functions. For “Supply creates its own Demand” must mean that f(N) and φ(N) are equal for all values of N, i.e. for all levels of output and employment; and that when there is an increase in Z( = φ(N)) corresponding to an increase in N, D( =f(N)) necessarily increases by the same amount as Z.

それに対して、「供給はそれ自身の需要を作り出す」と明確な形で言われ、正統派経済学の根底となり続けている古典派の教義は、上記の総需要と総供給の二つ の関数の間に特別な関係があることを前提とするものである。というのは、「供給はそれ自身の需要を作り出す」ということは、Nの全ての値に対して、即ち産 出量と雇用量のあらゆるレベルに対て、f(N)とφ(N)が一致するということであり、さらに、Nの増加に対応するZ( =φ(N))の増加があるとき、D( = f(N))は必ずZと同じ量だけ増加することを意味する。

The classical theory assumes, in other words, that the aggregate demand price (or proceeds) always accommodates itself to the aggregate supply price; so that, whatever the value of N may be, the proceeds D assume a value equal to the aggregate supply price Z which corresponds to N. That is to say, effective demand, instead of having a unique(一意的な) equilibrium value, is an infinite range of values all equally admissible; and the amount of employment is indeterminate except in so far as the marginal disutility of labour sets an upper limit.

言い換えれば、古典派の理論は、総需要価格(つまり売上)は常に総供給価格に連動して変化して、Nの値が何であるかに関わらず、売上DはNに対応する総供給価格Zと同じ値をとると想定しているのだ。つまり、有効需要は一つの均衡値ではなく、可能な限りあらゆる範囲の値となるのである。そして雇用量を決めるものは「労働力の限界不効用」(=労働供給の公理)が決める雇用の上限だけとなる(=雇われたい人は全員雇われる)。

  If this were true, competition between entrepreneurs would always lead to an expansion of employment up to the point at which the supply of output as a whole ceases to be elastic, i.e. where a further increase in the value of the effective demand will no longer be accompanied by any increase in output. Evidently this amounts to the same thing as full employment. In the previous chapter we have given a definition of full employment in terms of the behaviour of labour. An alternative, though equivalent, criterion is that at which we have now arrived, namely a situation, in which aggregate employment is inelastic in response to an increase in the effective demand for its output. Thus Say's law, that the aggregate demand price of output as a whole is equal to its aggregate supply price for all volumes of output, is equivalent to the proposition that there is no obstacle to full employment. If, however, this is not the true law relating the aggregate demand and supply functions, there is a vitally important chapter of economic theory which remains to be written and without which all discussions concerning the volume of aggregate employment are futile.

もしこれが事実なら、雇用は起業家たちの間の競争によって常に拡張していき、産出物の供給が全体的に弾力性を失うところに、即ち、もはや有効需要の値(=実際の売上)の増加に産出量の増加が連動しなくなるところに到達することになる。これが「完全雇用」と同じことを意味するのは明らかである。前の章で我々は労働者の行動から見た「完全雇用」の定義(=第二公理を満たす状況、非自発的失業がない状況)を示した(■)。そして今や我々は同じ内容だがそれとは別のもう一つの完全雇用の基準に到達したのである。それは、雇用が生み出す産出量に応じて有効需要(=実際の売上)も増加していって、もはや総雇用が弾力性を失って有効需要の増加に応じることが出来なくなった状況である。そうすると、産出物全体の総需要価格は全産出量に対する総供給価格に等しいというセイの法則は、完全雇用に至る障害物は存在しない(=弾力性がなくなることはない)と言っているに等しい。しかし、もしセイの法則が総需要関数と総供給関数を関する真の法則でないのなら、まだ書かれていない経済理論の非常に重要な部分、それなしには総雇用量についてのあらゆる議論が無意味になってしまう部分が存在することになる。

II

  A brief summary of the theory of employment to be worked out in the course of the following chapters may, perhaps, help the reader at this stage, even though it may not be fully intelligible. The terms involved will be more carefully defined in due course. In this summary we shall assume that the money-wage and other factor costs are constant per unit of labour employed. But this simplification, with which we shall dispense later, is introduced solely to facilitate the exposition. The essential character of the argument is precisely the same whether or not money-wages, etc., are liable to change.

第2節

  以下の章で詳しく論ずることになる雇用理論をここで簡単にまとめておくのは、たとえあまり分かりよくはなくても、読者の役に立つだろう。ここに含まれる専門用語の詳しい定義は順を追って行う。この要約では、雇用労働1単位あたりの名目賃金やその他の要素費用は一定とする。しかし、のちに不要になるこの単純化は説明を容易にするためであって、名目賃金やその他の要素費用が変化しても議論の本質が変わることはない。

The outline of our theory can be expressed as follows. When employment increases,aggregate real income is increased. The psychology of the community is such that when aggregate real income is increased aggregate consumption is increased, but not by so much as income. Hence employers would make a loss if the whole of the increased employment were to be devoted to satisfying the increased demand for immediate consumption. Thus, to justify any given amount of employment there must be an amount of current investment sufficient to absorb the excess of total output over what the community chooses to consume when employment is at the given level.

我々の雇用理論の概略は次のように表すことができる。雇用が増加すると実質総所得が増加する。実質総所得が増加すると総消費が増加するが、総消費の増加は総所得の増加分より少ないのが、社会の心理である。だから、増加している当面の消費需要を満たすために増加している雇用の全てを振り向けてしまうと、使用者にロスが出ることになる。つまり、雇用量を正当化する(=企業家に損が出ない)ために、当期の投資量(=消費に回らなかった貯蓄)が充分存在して、全産出量が雇用レベルに対応する社会の消費量を上回る分(=生産超過分)を吸収できければならない。

For unless there is this amount of investment, the receipts of the entrepreneurs will be less than is required to induce them to offer the given amount of employment. It follows, therefore, that, given what we shall call the community's propensity to consume, the equilibrium level of employment, i.e. the level at which there is no inducement to employers(使用者) as a whole either to expand or to contract employment, will depend on the amount of current investment. The amount of current investment will depend, in turn, on what we shall call the inducement to invest; and the inducement to invest will be found to depend on the relation between the schedule of the marginal efficiency of capital and the complex of rates of interest on loans of various maturities and risks.

というのは、もしこの投資量がなけれれば、企業家の収入が、この雇用量を提供する気になるために必要なレベルを下回ってしまうからである。すると、我々が社会の消費性向と呼ぶものが一定とすると、雇用の均衡レベル、即ち、全ての使用者がもはや雇用を拡大も縮小もしたくなくなるレベルは、当期の投資量によって決まることになる。そして、その当期の投資量は我々が「投資のインセンティブ」と呼ぶものによって決まることになり、さらに、この投資のインセンティブは、様々なリスクと満期をもつローンの利子率複合体(=13章2節。期間によって異なる利子率を総称したもの)と「資本の限界効率表」(=11章)との関係によって決まることが見出されるだろう。

Thus, given the propensity to consume and the rate of new investment, there will be only one level of employment consistent with equilibrium; since any other level will lead to inequality between the aggregate supply price of output as a whole and its aggregate demand price. This level cannot be greater than full employment, i.e. the real wage cannot be less than the marginal disutility of labour.

つまり、消費性向と新たな投資水準が決まると、均衡状態と矛盾しない雇用レベルは一つだけになる。他の雇用レベルでは産出物全体の総供給価格とその総需要価格が一致しなくなるからである。この雇用レベルは完全雇用を上回ることはありえない。つまり、実質賃金が「労働力の限界不効用」を下回る可能性はないのである。

 But there is no reason in general for expecting it to be equal to full employment.The effective demand associated with full employment is a special case, only realised when the propensity to consume and the inducement to invest stand in a particular relationship to one another. This particular relationship, which corresponds to the assumptions of the classical theory, is in a sense an optimum relationship. But it can only exist when, by accident or design, current investment provides an amount of demand just equal to the excess of the aggregate supply price of the output resulting from full employment over what the community will choose to spend on consumption when it is fully employed.

しかしながら、概してこの雇用レベルが完全雇用と等しいと予想する理由はない。有効需要が完全雇用を伴うのは、消費性向と投資インセンティブが互いに特殊な関係にあるときだけ実現される特別なケースだからである。この特殊な関係は古典派理論の様々な想定に対応しており、ある意味では最適な関係と言えるものである。しかしながら、この最適な関係が生まれるのは限られている。それは、故意か偶然でも、完全雇用から生まれる産出物の総供給価格が完全雇用のときの社会の消費量を上回る分に丁度等しいだけの需要量を、当期の投資が提供できるときだけである。

This theory can be summed up in the following propositions:

(1) In a given situation of technique, resources and costs, income (both money-income and real income) depends on the volume of employment N.

(2) The relationship between the community's income and what it can be expected to spend on consumption, designated by D1, will depend on the psychological characteristic of the community, which we shall call its propensity to consume. That is to say, consumption will depend on the level of aggregate income and, therefore, on the level of employment N, except when there is some change in the propensity to consume.

(3) The amount of labour N which the entrepreneurs decide to employ depends on the sum (D) of two quantities, namely D1, the amount which the community is expected to spend on consumption, and D2, the amount which it is expected to devote to new investment. D is what we have called above the effective demand.

この雇用理論は以下の命題にまとめられる。

(1)技術と資源と経費を一定とした場合、所得(名目所得と実質所得)は雇用量Nによって決まる。

(2)社会の所得と社会が消費に支出することを予想される量ーこれをD1とするーとの関係は社会の心理的傾向によって決まる。この心理的傾向を我々はその 社会の「消費性向」と呼ぶことにする。つまり、消費性向に変化がない限り、消費は総所得の水準によって、したがって、雇用レベルNによって決まる。

(3)企業家が雇用することを決める労働者の量Nは、次の二つの量の合計(D)によって決まる。即ち、Dは社会が消費に支出することを予想される量D1(=消費)と社会が新たな投資に振り向けると予想される量D2(=投資)の合計である。Dは我々が上記において「有効需要」と呼んだものとなる。

(4) Since D1 + D2 = D = φ(N), where φ is the aggregate supply function, and since, as we have seen in (2) above, D1 is a function of N, which we may write χ(N), depending on the propensity to consume, it follows that φ(N) - χ(N) = D2.

(4)φは総供給関数(=Z)で(=均衡状態なので)D1 + D2 = D = φ(N)であり、上記(2)で見たようにD1はNの関数でχ(N)と書くと、これは消費性向に依存する関数である。そうすと、(D-D1=D2だから)φ(N) - χ(N) = D2となる。

(5) Hence the volume of employment in equilibrium depends on (i) the aggregate supply function, φ, (ii) the propensity to consume, χ, and (iii) the volume of investment, D2. This is the essence of the General Theory of Employment.

(5)すると均衡状態にある雇用量(=N)は、(i)総供給関数φと(ii)消費性向χと(iii)投資量D2によって決まることになる。これが「雇用の一般理論」のかなめである。

(6) For every value of N there is a corresponding marginal productivity of labour in the wage-goods industries; and it is this which determines the real wage. (5) is, therefore, subject to the condition that N cannot exceed the value which reduces the real wage to equality with the marginal disutility of labour. This means that not all changes in D are compatible with our temporary assumption that money-wages are constant. Thus it will be essential to a full statement of our theory to dispense with this assumption.

(6)賃金財産業の労働の限界生産力はどのNの値(=雇用量)にも対応して存在する。そしてこの限界生産力が実質賃金を決定する(=労働需要の公理)。し たがって、(5)の命題は、Nの値は、実質賃金が労働力の限界不効用と等しくなる(=完全雇用、労働供給)値を上回れないという条件が付く。このことは、 D(=有効需要)のあらゆる変化と名目賃金(=Nによって決まる)を一定とする上記の仮定(→第3章第2節第1段落)が必ずしも両立するわけではないことを意味する。この仮定を撤去することは我々の雇用理論の本格的な記述には欠かせないのである。

(7) On the classical theory, according to which D = φ(N) for all values of N, the volume of employment is in neutral equilibrium for all values of N less than its maximum value; so that the forces of competition between entrepreneurs may be expected to push it to this maximum value. Only at this point, on the classical theory, can there be stable equilibrium.

(7)Nのあらゆる値に対して D=φ(N) が成り立つ古典派の理論(=需要と供給が一致する)では、Nの最大値(=完全雇用)を除くあらゆるNの値において、雇用量は不安定な均衡状態にある。その結果、企業家たちの競争によって雇用がこの最大値にまで押し上げられることが予想されるのである。古典派の理論では、この最大点においてだけ安定した均衡が可能となる。

(8) When employment increases, D1 will increase, but not by so much as D; since when our income increases our consumption increases also, but not by so much. The key to our practical problem is to be found in this psychological law. For it follows from this that the greater the volume of employment the greater will be the gap between the aggregate supply price (Z) of the corresponding output and the sum (D1) which the entrepreneurs can expect to get back out of the expenditure of consumers.

(8)雇用が増加すると、D1(=消費)も増加するが、それはD(=所得)の増加分よりは少ない。所得が増加すると消費も増加するが、それは所得の増加分より少ないからである。我々が抱えている現実の問題に対する鍵はこの心理法則の中に見出すことが出来る。というのは、この心理法則のせいで、雇用量が増えれば増えるほど、それに見合った産出物の総供給価格(Z)と、企業家が消費者の支出から回収することを予想できる額(D1)とのギャップが大きくなるからである。

Hence, if there is no change in the propensity to consume, employment cannot increase, unless at the same time D2 is increasing so as to fill the increasing gap between Z and D1. Thus ― except on the special assumptions of the classical theory according to which there is some force in operation which, when employment increases, always causes D2 to increase sufficiently to fill the widening gap between Z and D1 ― the economic system may find itself in stable equilibrium with N at a level below full employment, namely at the level given by the intersection of the aggregate demand function with the aggregate supply function.

したがって、もし「消費性向」に変化がないなら、Z(=総供給価格)とD1(=消費)の間の拡大するギャップを埋めるために、D2(=投資)が増加しない限り、雇用が増えることは不可能である。つまり、総需要関数と総供給関数が交差するレベルにあるN(=雇用)が完全雇用より低いレベルのままで、経済が安定した均衡状態に入ってしまう可能性があることになる。古典派の理論の特殊な想定のように、雇用が増加すると、D2を常に増加させる何らかの力が働いて、 ZとD1の間の拡大するギャップを埋めてくれるなら話は別であるが。

Thus the volume of employment is not determined by the marginal disutility of labour measured in terms of real wages, except in so far as the supply of labour available at a given real wage sets a maximum level to employment. The propensity to consume and the rate of new investment determine between them the volume of employment, and the volume of employment is uniquely related to a given level of real wages ― not the other way round. If the propensity to consume and the rate of new investment result in a deficient effective demand, the actual level of employment will fall short of the supply of labour potentially available at the existing real wage, and the equilibrium real wage will be greater than the marginal disutility of the equilibrium level of employment.

つまり、雇用量を決めるのは実質賃金で測った「労働力の限界不効用」ではないのである。ある実質賃金のもとで利用可能な労働の供給量は雇用の最大値を定め るだけなのである。雇用量を決めるのは消費性向(=D1)と新たな投資水準(=D2)の二つなのである。そして、その雇用量はあるレベルの実質賃金と一意的なつながりをもってはいても、その逆に実質賃金が雇用量を決めるこはないのである。もし消費性向と新たな投資水準が有効需要の不足をもたらしたなら、実 際の雇用レベルは現行実質賃金で潜在的に利用可能な労働の供給量を下回ることになるのだ。そして、その時に均衡した実質賃金は雇用の均衡レベルである限界不効用(=完全雇用)より高くなるのである(=実質賃金の高止まり)。

This analysis supplies us with an explanation of the paradox of poverty in the midst of plenty. For the mere existence of an insufficiency of effective demand may, and often will, bring the increase of employment to a standstill before a level of full employment has been reached. The insufficiency of effective demand will inhibit the process of production in spite of the fact that the marginal product of labour still exceeds in value the marginal disutility of employment.

この分析によって我々は豊かさのただ中における貧困というパラドックスの説明を手に入れる。というのは、有効需要が不足しているだけで、雇用の増加は完全雇用のレベルに達する前に止まってしまうかもしれず、またしばしば実際に止まってしまうからである。労働力の限界生産物(=労働需要の公理、企業側の提示する賃金)が雇用労働力の限界不効用(=労働供給の公理、労働側が要求する賃金)を価格において上回っているにも関わらず、有効需要の不足は生産の過程をストップさせてしまうのである。

Moreover the richer the community, the wider will tend to be the gap between its actual and its potential production; and therefore the more obvious and outrageous the defects of the economic system. For a poor community will be prone to consume by far the greater part of its output, so that a very modest measure of investment will be sufficient to provide full employment; whereas a wealthy community will have to discover much ampler opportunities for investment if the saving propensities of its wealthier members are to be compatible with the employment of its poorer members.

そのうえ、社会が豊かになればなるほど、実際の生産量と潜在的な生産量の間のギャップはますます広がっていき、それに従って、経済システム(=現代資本主義)の欠陥は次第にあらわとなり、暴力的になってくるのである。というのは、貧しい社会では産出物のかなり大きな部分が消費されてしまう傾向があるので、ごく控えめな投資でも充分に完全雇用をもたらすのに対して、豊かな社会では、もし富裕層の貯蓄性向と貧困層の雇用を両立させるつもりなら、かなり豊富な投資機会が見出されねばならないからである。

  If in a potentially wealthy community the inducement to invest is weak, then, in spite of its potential wealth, the working of the principle of effective demand will compel it to reduce its actual output, until, in spite of its potential wealth, it has become so poor that its surplus over its consumption is sufficiently diminished to correspond to the weakness of the inducement to invest.

もし潜在的に豊かな社会で投資のインセンティブが弱ければ、その潜在的な豊かさに関わらず、有効需要の原理の働きで実際の産出量は引き下げられ、最後には、その潜在的な豊かさにも関わらず、社会は貧困化していき(=豊かさの中の貧困)、消費を上回る余分の生産は投資のインセンティブの弱さに合った量まで減少することになる。

But worse still. Not only is the marginal propensity to consume[6] weaker in a wealthy community, but, owing to its accumulation of capital being already larger, the opportunities for further investment are less attractive unless the rate of interest falls at a sufficiently rapid rate; which brings us to the theory of the rate of interest and to the reasons why it does not automatically fall to the appropriate level, which will occupy Book IV.

しかし、もっと悪いことがある。豊かな社会では限界消費性向[6]が弱いだけでなく、資本の蓄積が既に大きいために、利子率が充分な早さで下がらないと、さらに投資する機会は魅力を失ってしまうのである。こうして、我々は利子率の理論へ向かい、適切なレベルまで利子率が自動的に下がらない理由を考えることになる。それは第4巻のことである。

Thus the analysis of the Propensity to Consume, the definition of the Marginal Efficiency of Capital and the theory of the Rate of Interest are the three main gaps in our existing knowledge which it will be necessary to fill. When this has been accomplished, we shall find that the Theory of Prices falls into its proper place as a matter which is subsidiary to our general theory. We shall discover, however, that Money plays an essential part in our theory of the Rate of Interest; and we shall attempt to disentangle the peculiar characteristics of Money which distinguish it from other things.

つまり、「消費性向」の分析と「資本の限界効率」の定義と「利子率」の理論こそは、現代の我々の知識からぽっかり抜け落ちている要素であり、この空隙を是非とも埋める必要があるのである。それが達成されたとき、「物価の理論」がこの一般理論の副次的な問題として相応しい居場所を見つけることになる。一方、我々の「利子率」の理論のなかでは「貨幣」は極めて重要な役割をしめていることが見出されるはずである。また「貨幣」が他のものと異なる特性をもっていることが明らかにされるだろう。

III

The idea that we can safely neglect the aggregate demand function is fundamental to the Ricardian economics, which underlie what we have been taught for more than a century. Malthus, indeed, had vehemently opposed Ricardo's doctrine that it was impossible for effective demand to be deficient; but vainly. For, since Malthus was unable to explain clearly (apart from an appeal to the facts of common observation) how and why effective demand could be deficient or excessive, he failed to furnish an alternative construction;

第3節

  総需要関数は無視しても構わないとする思想は、100年以上の間我々が教えられてきた経済学の基本となっているリカード経済学の根本思想である。確かに、有効需要(=消費予想+投資予想)が不足するなどありえないとするリカードの教義にマルサスは激しく反対したがうまくいかなった。というのは、マルサスはどうして有効需要が不足したり過剰になったりするのかうまく説明でず、単に常識的な観察的事実に訴えるしかなかったので、リカードに取って代わる体系を提示することができなかったからである。

and Ricardo conquered England as completely as the Holy Inquisition conquered Spain. Not only was his theory accepted by the city, by statesmen and by the academic world. But controversy ceased; the other point of view completely disappeared; it ceased to be discussed. The great puzzle of Effective Demand with which Malthus had wrestled vanished from economic literature. You will not find it mentioned even once in the whole works of Marshall, Edgeworth and Professor Pigou, from whose hands the classical theory has received its most mature embodiment. It could only live on furtively, below the surface, in the underworlds of Karl Marx, Silvio Gesell or Major Douglas.

そして、宗教裁判がスペインを征服したようにしてリカードは英国を完全に征服してしまった。彼の理論はロンドンの金融街にも政界にも学界にも受け入れられただけでなく、論争自体が終わってしまったのである。別の見方は完全に姿を消してしまい、もはや議論の対象にならなくなってしまった。そして、マルサスが取り組んだ「有効需要」という巨大な謎は経済書の中から姿を消してしまったのである。古典派の理論を成熟した形で完成させたマーシャルとエッジワースとピグー教授の本には有効需要という言葉はどこにも見当たらない。カール・マルクスとシルヴィオ・ゲゼルとダグラス少佐のいた裏世界で、ひっそりと命を長らえていただけなのである。

The completeness of the Ricardian victory is something of a curiosity and a mystery. It must have been due to a complex of suitabilities in the doctrine to the environment into which it was projected. That it reached conclusions quite different from what the ordinary uninstructed person would expect, added, I suppose, to its intellectual prestige. That its teaching, translated into practice, was austere and often unpalatable, lent it virtue. That it was adapted to carry a vast and consistent logical superstructure, gave it beauty.

リカードの勝利の完璧さは不思議なほどで興味をそそられる。リカードの教義にはそれが提示された環境に対する様々な適応力があったに違いない。彼の教義は一般の無教養の人たちにとっては予想外の結論に至るものだったが、それによって知的権威が付加された。また、実行に移された彼の教えは禁欲的でしばしば口に苦いものであったが、それによって美徳が付け加わった。さらに、彼の教義は広範かつ一貫性のある論理的上部構造をもつように作られていたので、美しさも備わっていた。

That it could explain much social injustice and apparent cruelty as an inevitable incident in the scheme of progress, and the attempt to change such things as likely on the whole to do more harm than good, commended(推薦する) it to authority. That it afforded a measure of justification to the free activities of the individual capitalist, attracted to it the support of the dominant social force behind authority.

彼の教義は、多くの社会的不公正と明らかな冷酷さを進歩の過程における避けがたいことだと説明し、そのような状況を変えようとする試みは総じて有益であるよりはむしろ有害なものだと説明したことで、権力者たちの寵愛を手に入れた。彼の教義は、個々の資本家の自由な行動を正当化する手段を与えたことで、権力の後ろにいる社会の支配層の支持をも獲得した。

But although the doctrine itself has remained unquestioned by orthodox economists up to a late date, its signal failure for purposes of scientific prediction has greatly impaired, in the course of time, the prestige of its practitioners. For professional economists after Malthus were apparently unmoved by the lack of correspondence between the results of their theory and the facts of observation;― a discrepancy which the ordinary man has not failed to observe, with the result of his growing unwillingness to accord to economists that measure of respect which he gives to other groups of scientists whose theoretical results are confirmed by observation when they are applied to the facts.

しかしながら、教義自体は最近まで正統派経済学者たちから何ら問題視されることなく存続したにもかかわらず、科学的予見で明らかに失敗したため、実際的な信用は大きく失われて行った。というのは、マルサス以降のプロの経済学者たちは、自分たちの理論と観察的事実の間につながりがないことを気にしなかったように見えるが、この食い違いは一般の目には明らかだったからである。他の分野の科学者がその理論的結果を事実に適用して、観察によって確認することで一般の尊敬をかち得たのに対して、経済学者はそのような尊敬を得ることはなかったのである。

The celebrated optimism of traditional economic theory, which has led to economists being looked upon as Candides, who, having left this world for the cultivation of their gardens, teach that all is for the best in the best of all possible worlds provided we will let well alone(現状のままにしておく), is also to be traced, I think, to their having neglected to take account of the drag on prosperity which can be exercised by an insufficiency of effective demand.

伝統的な経済理論のよく知られた楽観主義のおかげで、経済学者たちはカンディード(=ヴォルテール作)たちであると言われるようになっていた。彼らは自分たちだけの庭を耕すためにこの世を捨てて、現状をあるがままに認めさえすれば最善の世界において全てが最善の結果を迎えると教えているのである。この楽観主義の起源もまた元をたどれば、有効需要の不足が繁栄の足を引っ張る可能性に当時の経済学者たちが一顧だにしなかったことによると思われる。

For there would obviously be a natural tendency towards the optimum employment of resources in a Society which was functioning after the manner of the classical postulates. It may well be that the classical theory represents the way in which we should like our Economy to behave. But to assume that it actually does so is to assume our difficulties away.

というのは、古典派の公理のとおりに機能する「社会」では、自然に任せておけば人的資源の最適雇用が実現されることが明白だからである。おそらく古典派の理論は「経済」にどのような振舞いをして欲しいかを表わしたものなのだろう。しかしながら、実際の経済がそのように振舞うと想定するのは、この世の中に困難など存在しないと想定することと同じことなのである。

Author's Footnotes

[1]. A precise definition of user cost will be given in Chapter 6.

[2]. Not to be confused (vide infra) with the supply price of a unit of output in the ordinary sense of this term.

[3]. The reader will observe that I am deducting the user cost both from the proceeds and from the aggregate supply price of a given volume of output, so that both these terms are to be interpreted net of(除いた、差し引いた、含めない) user cost; whereas the aggregate sums paid by the purchasers are, of course, gross of(含めた) user cost. The reasons why this is convenient will be given in Chapter 6. The essential point is that the aggregate proceeds and aggregate supply price net of user cost can be defined uniquely(一意に) and unambiguously; whereas, since user cost is obviously dependent both on the degree of integration of industry and on the extent to which entrepreneurs buy from one another, there can be no definition of the aggregate sums paid by purchasers, inclusive(=gross) of user cost, which(=先行詞はdefinition) is independent of these factors. There is a similar difficulty even in defining supply price in the ordinary sense for an individual producer; and in the case of the aggregate supply price of output as a whole serious difficulties of duplication are involved, which have not always been faced. If the term is to be interpreted gross of user cost, they can only be overcome by making special assumptions relating to the integration of entrepreneurs in groups according as they produce consumption-goods or capital-goods<,> which are obscure and complicated in themselves and do not correspond to the facts. If, however, aggregate supply price is defined as above net of user cost, the difficulties do not arise. The reader is advised, however, to await the fuller discussion in Chapter 6 and its appendix.

[4]. An entrepreneur, who has to reach a practical decision as to his scale of production, does not, of course, entertain a single undoubting expectation of what the sale-proceeds of a given output will be, but several hypothetical expectations held with varying degrees of probability and definiteness. By his expectation of proceeds I mean, therefore, that expectation of proceeds which, if it were held with certainty, would lead to the same behaviour as does the bundle of vague and more various possibilities which actually makes up his state of expectation when he reaches his decision.

[5]. In Chapter 20 a function closely related to the above will be called the employment function.

[6]. Defined in Chapter 10, below.


著者注

[1] 使用費用の正確な定義は第6章で行われる。

[2]  用語の普通の意味での産出単位の供給価格と混同してはならない(下記を見よ)。

[3] 読者はお気づきだろうが、私は所与の量の産出物の「売上」にも「総供給価格」(=Z)にも使用費用を含めていない。だから、買い手が支払う総額に は当然使用費用が含まれることになるが、「売上」と「総供給価格」の項目は使用費用を含まない「正味」の額と解釈してもらいたい。こうするのが便利な理由は第6章で明らかにされる。要するに、使用費用を含めないほうが総売上と総供給価格を曖昧ではなく一意に定義できるのである。その一方で、使用費用は産業の統合度や起業家たちの間の売り買いの程度で明らかに違ってくるので、こうした要素を別にして買い手の支払い総額を定義することは不可能である。支払総額には必ず使用費用が含まれているのである。個々の生産者にとって普通の意味での供給価格を定義するのさえ同じくらい難しい。これまではあまり直視されなかったが、産出物全体の総供給価格の場合には二重計算という深刻な問題がある。もしこの項目を使用費用込みで解釈したければ、二重計算の問題を克服するために、企業家たちが消費財を製造するか資本財を製造するかにしたがってグループ別に統合されているという特殊な想定をするほかないが、これは曖昧で複雑であり事実にも反している。しかし、もし総供給価格を上記のように使用費用を含めず定義するなら、二重計算の問題は発生しない。しかし、これについての本格的な議論は第6章とその付録まで待ってほしい。

[4] もちろん、生産規模を実際に決めなければならない企業家は、一定の産出物の販売売上について明確なただ一つの予想値をもっているわけではなく、様々な仮定に基づく複数の予想値を持っているのであって、それらの蓋然性や確からしさも様々である。だから、わたしが言う「企業家の売上の予想値」とは、彼が決断するときにそれが確信を伴う場合であろうと、実際に予想される状況がもっと多様な可能性の集まりで漠然としている場合であろうと、同じ行動に導くようなものである。★

[5] 第20章では上記の関数と密接につながりを持つ関数が雇用関数と呼ばれることになる。

[6] のちに第10章で定義される。


Book II Definitions and Ideas

第2巻 定義と概念

Chapter 4. The Choice of Units

第4章 単位の選択 

I

  IN this and the next three chapters we shall be occupied with an attempt to clear up certain perplexities which have no peculiar or exclusive relevance to the problems which it is our special purpose to examine. Thus these chapters are in the nature of a digression, which will prevent us for a time from pursuing our main theme. Their subject-matter is only discussed here because it does not happen to have been already treated elsewhere in a way which I find adequate to the needs of my own particular enquiry.

第1節

  この章と次の三つの章では、ある種の困難を解決することに充てられる。これは我々がいま検討しようとしている問題とは特に何の関連性も持たない。したがっ て、以下の章は一種の脱線であり、我々のテーマからはしばらく外れることになる。こんな問題を私がここで扱うのは、私のこの研究の必要性を満たすほど充分 に検討されたことがないからにすぎない。

The three perplexities which most impeded my progress in writing this book, so that I could not express myself conveniently until I had found some solution for them, are: firstly, the choice of the units of quantity appropriate to the problems of the economic system as a whole; secondly, the part played by expectation in economic analysis; and, thirdly, the definition of income.

私がこの本を書き進めるにあたって障碍となった問題は三つあって、その解決策を見つけるまで、私は自分の考えをうまく表わすことが出来なかった。問題の第 一は、経済全体の問題を扱うのに相応しい数量単位の選択であり、第二は経済分析における予想値のはたす役割、第三は所得の定義である。

II

  That the units, in terms of which economists commonly work, are unsatisfactory can be illustrated by the concepts of the National Dividend, the stock of real capital and the general price-level:―

(i) The National Dividend, as defined by Marshall and Professor Pigou,[1] measures the volume of current output or real income and not the value of output or money-income.[2] Furthermore, it depends, in some sense, on net output; ― on the net addition, that is to say, to the resources of the community available for consumption or for retention as capital stock, due to the economic activities and sacrifices of the current period, after allowing for(=考慮に入れる、含める) the wastage(損耗費) of the stock of real capital existing at the commencement of the period.

第2節

  経済学者が仕事をするときによく使う単位が不充分なものであることは、例えば国民分配分、実物資本ストック、一般物価水準などの概念を見ればよくわかる。

(i)国民分配分は、マーシャルとピグー教授[1]の定義によれば、当期の産出高や実質所得(=実質国民所得)を表すもので、産出物の価格や名目所得を表 すものではない[2]。さらに、国民分配分を決めるのは純産出量であり、純産出量とは、消費にも使えるし資本の蓄積にも使える社会資源への純追加分であ る。この純追加分は当期の経済活動と出費から算出されるものであり、期間の初めに存在した実物資本ストックの損耗分も含まれる。

On this basis an attempt is made to erect a quantitative science. But it is a grave objection to this definition for such a purpose that the community's output of goods and services is a non-homogeneous complex which cannot be measured, strictly speaking, except in certain special cases, as for example when all the items of one output are included in the same proportions in another output.

この国民分配分の定義を基礎にして、数量科学を打ち建てる試みがなされているのだ。しかし、そんな目的を目指すにはこの定義には深刻な欠点がある。という のは、社会の財とサービスという産出物は同次性(=変数をk倍すると関数値もk倍になる)のない複合物であり、それを数量的に計測することは、厳密に言え ば、例えばある産出物の中の全項目が他の産出物の中に同じ割合で含まれているという特殊な場合以外には不可能だからである。

(ii) The difficulty is even greater when, in order to calculate net output, we try to measure the net addition to capital equipment; for we have to find some basis for a quantitative comparison between the new items of equipment produced during the period and the old items which have perished by wastage.

(ii) 純産出量を計算するために資本設備に対する純追加分を計算しようとすると、困難はさらに増大する。というのは、この期間中に作られた新しい設備の項目と消耗して失われた古い設備の項目とを数量的に比較する何らかの基準を見つけなければならないからである。

  In order to arrive at the net National Dividend, Professor Pigou[3] deducts such obsolescence,(陳腐化、老朽化、旧式化) etc., “as may fairly be called 'normal'; and the practical test of normality is that the depletion(消耗) is sufficiently regular to be foreseen, if not in detail, at least in the large.” But, since this deduction is not a deduction in terms of money, he is involved(巻き込まれて) in assuming that there can be a change in physical quantity, although there has been no physical change; i.e. he is covertly(こっそり) introducing changes in value.

ピグー教授[3]は純国民分配分を算出するに際して、「旧式化した」など「通常の消耗と呼ぶのがふさわしい」ものは差し引いている。そして「その消耗が通 常のものであるかどうかは、消耗が異常なものではなく、その詳細を見通せなくても大体は予想がつくものである」と言うのである。しかし、この控除は金額に よるものではないので、彼は物に変化がなくても物の量的変化が起こり得るとする想定に陥っている。つまり、彼はこっそりと値(=収益)の変化を持ち込んで いるのである。

Moreover, he is unable to devise any satisfactory formula[4] to evaluate new equipment against old when, owing to changes in technique, the two are not identical. I believe that the concept at which Professor Pigou is aiming is the right and appropriate concept for economic analysis. But, until a satisfactory system of units has been adopted, its precise definition is an impossible task. The problem of comparing one real output with another and of then calculating net output by setting off new items of equipment against the wastage of old items presents conundrums(難問) which permit, one can confidently say, of no solution.

その上、彼は新しい設備と古い設備が技術の変遷で最早同じものとは言えなくなった時に両者の違いを数値化する充分な計算式[4]を作り出せないのである。 私はピグー教授の目指している概念(=国民分配分)自体は正しいし経済の分析に相応しいものだと思う。しかし、数量単位の充分な体系が採用されるまでは、 その概念を正確に定義することは不可能である。ある実物産出量を他の実物産出量と比べて、次に古い設備項目の消耗を新しい設備項目から差し引いて純産出量 をはじき出すという問題は永遠の謎であり、その問には答えがないと自信をもって言える。

(iii) Thirdly, the well-known, but unavoidable, element of vagueness which admittedly attends the concept of the general price-level makes this term very unsatisfactory for the purposes of a causal analysis, which ought to be exact.

(iii) 第三に、「一般物価水準」という概念に、避け難い曖昧さが付きまとうことはよく知られている。そのおかげで「一般物価水準」という言葉は、正確さを必要とする原因分析という目的には不充分なものとなっている。

Nevertheless these difficulties are rightly regarded as “conundrums.” They are “purely theoretical” in the sense that they never perplex, or indeed enter in any way into, business decisions and have no relevance to the causal sequence of economic events, which are clear-cut and determinate in spite of the quantitative indeterminacy of these concepts. It is natural, therefore, to conclude that they not only lack precision but are unnecessary. Obviously our quantitative analysis must be expressed without using any quantitatively vague expressions. And, indeed, as soon as one makes the attempt, it becomes clear, as I hope to show, that one can get on much better without them.

それにも関わらず、いやそれだからこそ、これらの問題はまさに「謎々」と呼ぶのがふさわしいである。というのは、それらは純粋に理論的な問題であり、ビジ ネスの決定を複雑にするどころか、それとは何の関わりもないものであり、経済現象の因果関係とも全く無関係だからである。経済現象の因果関係は上記の概念 が数量的に漠然としているにも関わらず、明瞭ではっきりしている。したがって、上記の概念は不正確であるだけでなく不必要だと結論するのが自然である。我 々の量的分析は量的に曖昧な表現を使わずに行われねばならないのは明らかである。そして、実際のところ、量的分析をしようとすれば、私が示そうとしたとお りに、そんな概念がない方が遥かにうまく行くのである。

The fact that two incommensurable(同じ基準で測れない) collections(集合) of miscellaneous (種々雑多なものからなる)objects(物、対象) cannot in themselves provide the material for a quantitative analysis need not, of course, prevent us from making approximate statistical comparisons, depending on some broad element of judgment rather than of strict calculation, which may possess significance and validity within certain limits. But the proper place for such things as net real output and the general level of prices lies within the field of historical and statistical description, and their purpose should be to satisfy historical or social curiosity, a purpose for which perfect precision ― such as our causal analysis requires, whether or not our knowledge of the actual values of the relevant quantities is complete or exact ― is neither usual nor necessary.

もっとも、種々雑多なものからなる二つの集合を同じ基準で測ることはできないから、それ自体は数量的分析の対象にはできないとしても、この二つを統計上大 まかに比較することが不可能というわけではない。それは厳密な計算というよりは大雑把な判断材料によるもので、ある程度の範囲内でなら有意義で価値あるも のかもしれない。しかしながら、実際の純産出量や一般物価水準のようなものにとって相応しい居場所は、歴史的で統計的な記述の領域であって、その目的は歴 史的なあるいは社会的な興味を満たすものである。そのような目的には完璧な精度は無用であり不要でもある。しかし、我々の原因分析には、関係する数量の実 際の値が正確で完全なものであるかどうかには関わらず、完璧な精度が必要なのである。

To say that net output to-day is greater, but the price-level lower, than ten years ago or one year ago, is a proposition of a similar character to the statement that Queen Victoria was a better queen but not a happier woman than Queen Elizabeth ― a proposition not without meaning and not without interest, but unsuitable as material for the differential calculus(微分). Our precision will be a mock(偽の) precision if we try to use such partly vague and non-quantitative concepts as the basis of a quantitative analysis.

「10年前よりいや1年前よりも今日の純産出量は大きいが、物価水準は低い」などと言うことは、ヴィクトリア女王はエリザベス女王よりよい女王だったが女 としては幸せではなかったと言うのと似たような主張であり、無意味な主張でもつまらない主張でもないが、微積分の対象としては不向きである。もし我々がそ のような漠然とした数量的でない概念を数量分析の基本として使うとしたら、我々の正確さは偽りの物となるだろう。


III

  On every particular occasion, let it be remembered, an entrepreneur is concerned with decisions as to the scale on which to work(動かす) a given capital equipment; and when we say that the expectation of an increased demand, i.e. a raising of the aggregate demand function(関数の上方へのシフト? 関数の値の増加?), will lead to an increase in aggregate output, we really mean that the firms, which own the capital equipment, will be induced to associate with it a greater aggregate employment of labour. In the case of an individual firm or industry producing a homogeneous product we can speak legitimately, if we wish, of increases or decreases of output. But when we are aggregating the activities of all firms, we cannot speak accurately except in terms of quantities of employment applied to a given equipment.

第3節

  忘れてならないのは、いついかなる場合にも企業家は今ある資本設備をどの規模で動かすべきかを決めることに関心があるということである。そして、「需要の 増加(総需要関数の上方へのシフト)への予想が、総産出量の増加を導く」と我々が言う時、それは実際には「資本設備を持つ企業が、それにともなって労働の 総雇用量を増やす気になる」ということを意味する。同次性(=既出)のある生産物を作る個々の企業や産業の場合は、必要なら産出量の増加や減少について正 確に語ることはできる。しかし、すべての企業の活動を集計しようとするなら、一定の資本設備に向けられた雇用量についてだけしか正確に語ることはできな い。

The concepts of output as a whole and its price-level are not required in this context, since we have no need of an absolute measure of current aggregate output, such as would enable us to compare its amount with the amount which would result from the association of a different capital equipment with a different quantity of employment. When, for purposes of description or rough comparison, we wish to speak of an increase of output, we must rely on the general presumption that the amount of employment associated with a given capital equipment will be a satisfactory index of the amount of resultant output; ― the two being presumed to increase and decrease together, though not in a definite numerical proportion.

この目的には全産出量とかその物価水準などという概念は必要ない。というのは、我々には当期の総産出量を計測する絶対的な尺度は必要ないし、それによって 異なる資本設備と異なる雇用量の組み合わせから生まれる総産出量と現状の総産出量を比較できるようにする必要はないからである。大雑把な比較や説明が目的 で産出量の増加について語りたいときには、一定の資本設備にともなう雇用量がそこから生まれる産出量の満足な指標となるという漠然とした推測を頼りにしな ければならない。雇用量と産出量の増減は、たとえ一定の割合ではなくても、同時に起こると考えられるからである。

  In dealing with the theory of employment I propose, therefore, to make use of only two fundamental units of quantity, namely, quantities of money-value and quantities of employment. The first of these is strictly homogeneous, and the second can be made so. For, in so far as different grades and kinds of labour and salaried assistance enjoy a more or less fixed(固定した) relative remuneration(報酬), the quantity of employment can be sufficiently defined for our purpose by taking an hour's employment of ordinary labour as our unit and weighting(加重値をつける) an hour's employment of special labour in proportion to its remuneration; i.e. an hour of special labour remunerated at double ordinary rates will count as two units. We shall call the unit in which the quantity of employment is measured the labour-unit; and the money-wage of a labour-unit we shall call the wage-unit(単位賃金).[5] Thus, if E is the wages (and salaries) bill, W the wage-unit, and N the quantity of employment, E = NxW

したがって、私は雇用理論を扱うときに使用する基本的な数量単位を二つだけにすることを提案する。それは、貨幣価格量と雇用量である。このうち最初のもの は厳密な同次性(=既出)を持っているし、二番目のものには同次性を持たせることが出来る。というのは、異なる等級と種類の労働は相対的に固定された報酬 をもたらすため、普通の労働による1時間の雇用を1単位とし、特別な労働による1時間の雇用を報酬に応じて加重することによって、雇用量は我々の目的に とって充分に定義可能なものとなる。つまり、普通の労働の倍の報酬をもたらす特別な労働の1時間を2単位として数えるのである。雇用量が計算される単位は 単位労働(=時間数と考える)と呼ぶことにする。そして単位労働の名目賃金を単位賃金(=時間あたりの賃金と考える)と呼ぶことにする[5]。そうする と、Eを賃金の総額とし、Wを単位賃金とし、Nを雇用量(=時間)とするとき、E=N×Wとなる。

This assumption of homogeneity in the supply of labour is not upset by the obvious fact of great differences in the specialised skill of individual workers and in their suitability for different occupations. For, if the remuneration of the workers is proportional to their efficiency, the differences are dealt with by our having regarded individuals as contributing to(寄与する) the supply of labour in proportion to their remuneration; whilst if, as output increases, a given firm has to bring in labour which is less and less efficient for its special purposes per wage-unit paid to it, this is merely one factor among others leading to a diminishing return from the capital equipment in terms of output as more labour is employed on it. We subsume(包含する), so to speak, the non-homogeneity of equally remunerated labour-units in the equipment, which we regard as less and less adapted to employ the available labour-units as output increases, instead of regarding the available labour-units as less and less adapted to use a homogeneous capital equipment.

労働供給における同次性の仮定は、個々の労働者の特殊技術や様々な仕事への適応力に大きな違いがあるという明らかな事実によって覆されることはない。とい うのは、労働者の報酬がその能力に比例したものなら、それらの違いは、個々の労働者はその報酬に比例して労働供給を増やしているとみなすことで対処できる からである。一方、もし産出量が増加するにつれて、ある企業が特別な仕事に対して次第に賃金効率の落ちる労働者を投入しなければならないとしても、それは 雇用が増えるにつれて資本設備から生ずる産出物の収益が次第に減少する要因の一つにすぎない。同じ報酬を得ている労働単位のいわば非同次性を、我々は資本 設備の中に組み込むのである。そして、利用可能な労働単位が同次性のある資本設備を使用するのに益々不適合になると見るかわりに、産出量が増加するにつれ て利用可能な労働単位を雇用するのに資本設備の方が益々不適合になると見るのである。

Thus if there is no surplus of specialised or practised labour and the use of less suitable labour involves a higher labour cost per unit of output, this means that the rate at which the return from the equipment diminishes as employment increases is more rapid than it would be if there were such a surplus.[6] Even in the limiting case where different labour-units were so highly specialised as to be altogether incapable of being substituted for one another, there is no awkwardness; for this merely means that the elasticity of supply of output from a particular type of capital equipment falls suddenly to zero when all the available labour specialised to its use is already employed.[7] Thus our assumption of a homogeneous unit of labour involves no difficulties unless there is great instability in the relative remuneration of different labour-units; and even this difficulty can be dealt with, if it arises, by supposing a rapid liability to change(名詞) in the supply of labour and the shape of the aggregate supply function.

だから、もし専門の労働者や熟練労働者が不足して、それより能力が落ちる労働者を使用することで、産出単位あたりの労働コストが増えたとしても、それは雇 用の増加にともなって資本設備からの収益の逓減する速度が、そのような不足がない場合よりも速くなることを意味するだけである[6]。異なる労働単位が高 度に専門化して互いに代用することが不可能であるという限定的な場合でも、困ることはない。なぜなら、それは、特殊なタイプの資本設備に特化された労働力 が全員雇用済みになったとき、その設備からの産出物の供給が急に弾力性を失うことを意味するにすぎないからである[7]。つまり、労働単位が同次性を持つ という我々の仮定には何の問題もない。ただし、異なる労働単位の相対的な報酬がまったく固定されない場合には話は別であるが、この問題が生じる場合も、労 働供給と総供給関数の形は変化を受けやすいと考えることで対処できる。

  It is my belief that much unnecessary perplexity can be avoided if we limit ourselves strictly to the two units, money and labour, when we are dealing with the behaviour of the economic system as a whole; reserving the use of units of particular outputs and equipments to the occasions when we are analysing the output of individual firms or industries in isolation; and the use of vague concepts, such as the quantity of output as a whole, the quantity of capital equipment as a whole and the general level of prices, to the occasions when we are attempting some historical comparison which is within certain (perhaps fairly wide) limits avowedly unprecise and approximate.

もし我々が経済全体の振る舞いを分析するときに使う単位を貨幣と労働の二つに厳密に限定するなら、不必要な複雑さを回避できるというのが私の信念である。 特別な産出量と資本設備の単位を使うのは、個別の企業や産業を他から切り離して分析するときのために残しておけばよいのである。また、産出量全体の量とか 資本設備全体の量とか一般物価水準といった曖昧な概念を使うのは歴史的な比較をする時にとっておけばいいのである。そのような比較がかなりの程度で精度を 欠いたおおまかなものであることは明らかだからである。

  It follows that we shall measure changes in current output by reference to the number of hours of labour paid for (whether to satisfy consumers or to produce fresh capital equipment) on the existing capital equipment, hours of skilled workers being weighted in proportion to their remuneration. We have no need of a quantitative comparison between this output and the output which would result from associating a different set of workers with a different capital equipment. To predict how entrepreneurs possessing a given equipment will respond to a shift in the aggregate demand function it is not necessary to know how the quantity of the resulting output, the standard of life and the general level of prices would compare with(~は~と比べてどうである) what they were at a different date or in another country.

したがって、我々は当期の産出量の変化を(消費者の欲望を満たすか新たな資本設備を生み出すために)現状の資本設備もとで賃金を支払われた労働時間数に よって計測することにする。その場合、熟練労働者の時間はその報酬に比例した加重値が付加される。このようにして計測した総産出量を、これとは異なる資本 設備と労働者の組み合わせから生まれる総産出量と量的に比較する必要はない。ある資本設備を持つ企業家たちが総需要関数のシフトにどのように反応するかを 予測するには、その設備から生まれる産出量と生活水準と一般物価水準が、別の時期や別の国であればどうなるかを知る必要はないのである。

IV

  It is easily shown that the conditions of supply, such as are usually expressed in terms of the supply curve, and the elasticity of supply relating output to price, can be handled in terms of our two chosen units by means of the aggregate supply function, without reference to quantities of output, whether we are concerned with a particular firm or industry or with economic activity as a whole. For the aggregate supply function for a given firm (and similarly for a given industry or for industry as a whole) is given by

Zr = φr(Nr),

第4節

  容易に示されるように、供給の状態(一般に供給曲線によって描かれる)と産出供給の価格弾力性は、我々が選んだ二つの単位(=貨幣と労働、ZとN)を使っ た総供給関数(=φ)によって扱うことができる。この場合、産出量に言及する必要はないし、我々の扱うものが個別の企業であろうと産業であろうと経済活動 全体であろうと関係はない。というのは、ある企業(ある産業でも産業全体でも同じ)の総供給関数は

Zr = φr(Nr),

で与えられるからである(=ここで添字rがr産業の数字であることを示すことは第20章冒頭にある。Xwについて後出)。

where Zr is the proceeds (net of user cost) the expectation of which will induce a level of employment Nr. If, therefore, the relation between employment and output is such that an employment Nr results in an output Or, where Or = ψr(Nr), it follows that

p = {Zr + Ur(Nr)}/Or = {φr(Nr) + Ur(Nr)}/ψr(Nr)

is the ordinary supply curve, where Ur(Nr) is the (expected) user cost corresponding to a level of employment Nr.

ここでZrは売上(使用費用を含めない)であり、それに対する予想が雇用レベルNrを誘発する。したがって、もし雇用と産出量の関係が、産出量Orが雇用Nrの結果であるとし、Or=ψr(Nr)であるとすると、ここから

p={Zr+Ur(Nr)}/Or={φr(Nr)+ Ur(Nr)}/ψr(Nr)(=単位産出量あたりの価格)

が通常の供給曲線となる。ここでUr(Nr)は雇用レベルNrに対する(予想された)使用費用である。

Thus in the case of each homogeneous commodity, for which Or = ψr(Nr) has a definite meaning, we can evaluate Zr = φr(Nr) in the ordinary way; but we can then aggregate the Nr's in a way in which we cannot aggregate the Or's, since ΣOr is not a numerical quantity. Moreover, if we can assume that, in a given environment, a given aggregate employment will be distributed in a unique way between different industries, so that Nr is a function of N, further simplifications are possible.

つまり、同次性のある個々の商品の場合には、Or=ψr(Nr)が明確な意味を持つので、Zr= φr(Nr)を通常の方法で評価できる。しかし、その際、Nrの合計は数字で出すことができるが、ΣOr(=Orの総和)は数字で表される量ではないの で、Nrと同じ様にOrの合計を数字で出すことは出来ない。さらに、もしある一定の環境のもとで一定の総雇用が様々な産業間に明確な仕方で配分されて、そ の結果NrはNの関数であると想定できるなら、これらはもっと単純化することが出来る。

Author's Footnotes

[1]. Vide Pigou, Economics of Welfare, passim, and particularly Part I. chap. iii.

[2]. Though, as a convenient compromise, the real income, which is taken to constitute the National Dividend, is usually limited to those goods and services which can be bought for money.

[3]. Economics of Welfare, Part I. chap. v., on “What is meant by maintaining Capital intact”; as amended by a recent article in the Economic Journal, June 1935, p. 225.

[4]. Cf. Prof. Hayek's criticisms, Economica, Aug. 1935, p. 247.

[5]. If X stands for any quantity measured in terms of money, it will often be convenient to write Xw for the same quantity measured in terms of the wage-unit.

[6]. This is the main reason why the supply price of output rises with increasing demand even when there is still a surplus of equipment identical in type with the equipment in use. If we suppose that the surplus supply of labour forms a pool equally available to all entrepreneurs and that labour employed for a given purpose is rewarded, in part at least, per unit of effort and not with strict regard to its efficiency in its actual particular employment (which is in most cases the realistic assumption to make), the diminishing efficiency of the labour employed is an outstanding example of rising supply price with increasing output, not due to internal diseconomies.

[7]. How the supply curve in ordinary use is supposed to deal with the above difficulty I cannot say, since those who use this curve have not made their assumptions very clear. Probably they are assuming that labour employed for a given purpose is always rewarded with strict regard to its efficiency for that purpose. But this is unrealistic. Perhaps the essential reason for treating the varying efficiency of labour as though it belonged to the equipment lies in the fact that the increasing surpluses, which emerge as output is increased, accrue(動詞、~に生ずる) in practice mainly to the owners of the equipment and not to the more efficient workers (though these may get an advantage through being employed more regularly and by receiving earlier promotion); that is to say, men of differing efficiency working at the same job are seldom paid at rates closely proportional to their efficiencies. Where, however, increased pay for higher efficiency occurs, and in so far as it occurs, my method takes account of it; since in calculating the number of labour-units employed, the individual workers are weighted in proportion to their remuneration. On my assumptions interesting complications obviously arise where we are dealing with particular supply curves since their shape will depend on the demand for suitable labour in other directions. To ignore these complications would, as I have said, be unrealistic. But we need not consider them when we are dealing with employment as a whole, provided we assume that a given volume of effective demand has a particular distribution of this demand between different products uniquely associated with it(=have A doneの構文).

著者注

[1] ピグー『厚生経済学』、特に第1部3章。

[2]  もっとも、国民分配分を構成するとみなされる実質所得(=実質国民所得)は通常はお金で買える財とサービスに限られており、これが便利な解決策となっている。

[3] 『厚生経済学』第1部第5章「資本を無傷で維持するとはどういう事か」。最近の論文(『エコノミック・ジャーナル』1935年6月225頁)で修正されている。

[4]  ハイエク教授の批判(『エコノミカ』1935年8月247頁)参照。

[5] もしXがお金で計測した量なら、同じ量を単位賃金で計測したものはXwと書くのが、多くの場合、便利だろう。

[6] 使用中の資本設備と同じタイプの設備が余っている時でも、需要が増加するにつれて産出物の供給価格が上昇する主な理由はこれである。余っている労 働力の供給がすべての企業家にとって公平に利用可能なようにプールされており(=有能な労働者だけを選べない)、ある目的で雇用された労働力の報酬が、少 なくも一部は単位労働ごとに支払われ、実際の個々の仕事の能率に厳密に対応するものではない(多くの場合これは現実的な想定である)と考えると、雇用され た労働力の効率が減少することは、産出量が増加するにつれて供給価格が上昇するのが内部不経済(=企業活動の拡大に伴うコストの増加)のせいではないこと の明らかな証拠である。

[7] 一般に使われている供給曲線(=上記のZ = φ(N)ではない産出量と価格のグラフ)がこの問題(=専門の労働者が全員雇用済みの場合)をどう扱うつもりでいるかを私は知らない。なぜなら、この曲線 を使っている人たちが自分たちの意図を明らかにしていないからである。おそらく彼らは、ある目的で雇用された労働者は常に仕事の能率に厳密に対応する報酬 を得ていると考えているのだろう。しかし、これは現実的ではない。多分、能率の異なる労働者たちを資本設備と一体であるかのように扱う方がよいと考えるべ き主な理由は、産出量の増加につれて増加する剰余利得は実際には主に設備の所有者のものになって能率の高い労働者のものにはならないという事実にある (もっとも彼らは正規に雇用されたり昇進が早まったりすることで得をするが)。つまり、作業能率が異なるのに同じ仕事をしている労働者たちがその能率に厳 密に比例した報酬を得ていることはめったにないのである。もっとも、私の方法は、高い能率に対して高い報酬が支払われている場合も、それが起こる限りは考 慮に入れている。というのは、雇用された単位労働の数を計算するときに、個々の労働者にその報酬に比例した加重値を付加するからである。私の想定では個々 の供給曲線を扱おうとする場合には興味深い難問が当然起こってくる。というのはそれらの曲線の形を決めるのはその仕事に向いていない人への需要だからであ る(=向いている人は全員雇用済みだから)。この問題を無視するのは、いま言ったように、現実的ではないだろう。しかし、雇用を全体として考える場合には この問題を検討する必要はない。ただし、この場合には所与の量の有効需要は、様々な生産物の間へ特別な仕方で配分されていて、しかもその配分の仕方以外に はないと想定されている(=第20章第4段落に再出)。

  It may be, however, that this would not hold good irrespective of the particular cause of the change in demand. E.g. an increase in effective demand due to an increased propensity to consume might find itself faced by a different aggregate supply function from that which would face an equal increase in demand due to an increased inducement to invest. All this, however, belongs to the detailed analysis of the general ideas here set forth, which it is no part of my immediate purpose to pursue.

しかしながら、この想定は需要の変化の特殊な原因と関係なく有効といういわけではない。例えば、消費性向の増大に起因する有効需要の増加が直面する総供給 関数は、投資インセンティブの増大に起因する有効需要の同じだけの増加が直面する総供給関数とは異なっているかもしれない。しかし、これらのことは、ここ で示した一般的な考え方を詳細に分析するときに関係してくることばかりで、私の当面の目的とは関係がない。


Chapter 5. Expectation as Determining Output and Employment

第5章 産出量と雇用を決めるものとしての予想

I

  ALL production is for the purpose of ultimately satisfying a consumer. Time usually elapses, however ― and sometimes much time ― between the incurring of costs by the producer (with the consumer in view) and the purchase of the output by the ultimate consumer. Meanwhile the entrepreneur (including both the producer and the investor in this description) has to form the best expectations[1] he can as to what the consumers will be prepared to pay when he is ready to supply them (directly or indirectly) after the elapse of what may be a lengthy period; and he has no choice but to be guided by these expectations, if he is to produce at all by processes which occupy time.

第1節

  全ての生産の最終的な目的は消費者の欲望を満たすことである。しかし、生産者が(消費者を視野に入れて)コストを負担してから最終的に産出物を消費者が購 入するまでの間には、時間がそれもしばしば非常に長い時間がかかる。その間に企業家(これには生産者と投資家の両方を含まれる)は、その長い時間がたった あとで産出物を(直接間接に)供給できるようになった時に、消費者がどれだけの金額を出そうとするかに関して予想[1]をうまく形成しなければならない。 もし企業家が長い時間のかかる生産活動をしようとすれば、この予想を道案内とするしかないのである。

These expectations, upon which business decisions depend, fall into two groups, certain individuals or firms being specialised in the business of framing the first type of expectation and others in the business of framing the second. The first type is concerned with the price which a manufacturer can expect to get for his “finished” output at the time when he commits himself to starting the process which will produce it; output being “finished” (from the point of view of the manufacturer) when it is ready to be used or to be sold to a second party. The second type is concerned with what the entrepreneur can hope to earn in the shape of future returns if he purchases (or, perhaps, manufactures) “finished” output as an addition to his capital equipment. We may call the former short-term expectation and the latter long-term expectation.

ビジネスの決断が拠り所とするこうした予想は二つのタイプに分かれる。個人や会社でも第一のタイプの予想形成に専念しているものと、第二のタイプの予想形 成に専念しているものがある。第一のタイプは予想とは、生産者の予想で、「完成した」産出物によって得られると予想できる価格を製造開始時点で予測するも のである。産出物が「完成した」とは(生産者の立場から見て)他人が使える或いは他人に売れる状態になっていることである。第二のタイプの予想とは、投資 家の予想で、企業家が「完成した」産出物を自分の資本設備に追加購入(あるいは製造)する場合(=設備投資)に、将来の収益として予想できる額を予測する ものである。我々は前者を短期予想、後者を長期予想と呼ぶことにする。

Thus the behaviour of each individual firm in deciding its daily[2] output will be determined by its short-term expectations ― expectations as to the cost of output on various possible scales and expectations as to the sale-proceeds of this output; though, in the case of additions to capital equipment and even of sales to distributors, these short-term expectations will largely depend on the long-term (or medium-term) expectations of other parties. It is upon these various expectations that the amount of employment which the firms offer will depend.

したがって、個々の企業が日々[2]の産出量を決めるときの行動は短期予想によって決まるのである。この短期予想は可能性のある様々な規模の産出量のコス トの予測と、その産出量から得られる販売の売上予測である。もっとも、複数の資本設備への追加の場合はもちろんのこと、卸売業者への販売の場合でさえ、こ れらの短期予想は他者(=買い手の)の長期(あるいは中期)予想に大きく左右される。企業はこうした様々な予想に基づいて雇用量を決めるのである。

The actually realised results of the production and sale of output will only be relevant to employment in so far as they cause a modification of subsequent expectations. Nor, on the other hand, are the original expectations relevant, which led the firm to acquire the capital equipment and the stock of intermediate products and half-finished materials with which it finds itself at the time when it has to decide the next day's output. Thus, on each and every occasion of such a decision, the decision will be made, with reference indeed to this equipment and stock, but in the light of the current expectations of prospective costs and sale-proceeds.

産出物の生産と販売から実際に実現された結果が雇用に影響してくるのは、これがその後の予想に変化をもたらす場合に限られている。その一方で、企業が翌日 の産出量を決めるときには、手元にある中間生産品や半完成品のストックと資本設備の入手を促した元の予測はもう重要ではない。つまり、そのような決断は、 その都度その都度、この資本設備やストックについて、将来のコストと販売売上に関する現在の予想を考慮して行われるのである。

Now, in general, a change in expectations (whether short-term or long-term) will only produce its full effect on employment over a considerable period. The change in employment due to a change in expectations will not be the same on the second day after the change as on the first, or the same on the third day as on the second(=not A or Bの構文), and so on, even though there be no further change in expectations.

ところで、一般に、(短期であれ長期であれ)予想の変化が充分に雇用に影響するまでには、かなり長い期間を要するものである。予想の変化による雇用の変化 は、予想の変化後二日目にはもう一日目と同じではないし、三日目は二日目と同じではない。このような繰り返しである。つまり、予想に変化がなくても雇用は 変化し続けるのである。

  In the case of short-term expectations this is because changes in expectation are not, as a rule, sufficiently violent or rapid, when they are for the worse, to cause the abandonment of work on all the productive processes which, in the light of the revised expectation, it was a mistake to have begun; whilst, when they are for the better, some time for preparation must needs elapse before employment can reach the level at which it would have stood if the state of expectation had been revised sooner.

その理由は短期予想の場合、予想は普通それほど急激にはも急速にも変化しないしからである。だから、予想が悪化した場合、作りなおされた予想から見れば生 産を始めたのが失敗だとわかっても、その生産の全過程の雇用を取りやめることにはならないし、予想が好転した場合でも、もっと早く予想を改めていれば到達 していたはずの雇用レベルに至るには準備期間が必要なのである。

  In the case of long-term expectations, equipment which will not be replaced will continue to give employment until it is worn out; whilst when the change in long-term expectations is for the better, employment may be at a higher level at first, than it will be after there has been time to adjust the equipment to the new situation.

長期予想の場合には、資本設備が(途中で取り替えられない限り)消耗するまでの間ずっと雇用がもたらされ続ける。その一方、長期予想が好転した場合には、雇用レベルが高くなるが、その後、設備が新しい状況に適応すると雇用が減少することがある。

  If we suppose a state of expectation to continue for a sufficient length of time for the effect on employment to have worked itself out so completely that there is, broadly speaking, no piece of employment going on<,> which would not have taken place if the new state of expectation had always existed, the steady level of employment thus attained may be called the long-period employment[3] corresponding to that state of expectation. It follows that, although expectation may change so frequently that the actual level of employment has never had time to reach the long-period employment corresponding to the existing state of expectation, nevertheless every state of expectation has its definite corresponding level of long-period employment.

ある一定の予想が長く続いて、その予想が雇用に及ぼす効果が完全に出尽くして、概してもはやどんな雇用も起こらなくなってしまう(新しい予想が常に存在す る場合にはそうはならないという)場合を想定すると、こうして到達された雇用の安定した段階をその予想に対応する「長期雇用」[3]と呼ぶことができる。 したがって、たとえ予想がしばしば変化して、実際の雇用レベルが現状の予想に対応する長期雇用に達する時間がなかったとしても、それぞれの予想の状態には それぞれに見合った明確な長期雇用のレベルが存在するということになる。

Let us consider, first of all, the process of transition to a long-period position due to a change in expectation, which is not confused or interrupted by any further change in expectation. We will first suppose that the change is of such a character that the new long-period employment will be greater than the old. Now, as a rule, it will only be the rate of input which will be much affected at the beginning, that is to say, the volume of work on the earlier stages of new processes of production, whilst the output of consumption-goods(=消費財) and the amount of employment on the later stages of processes which were started before the change will remain much the same as before. In so far as there were stocks of partly finished goods, this conclusion may be modified; though it is likely to remain true that the initial increase in employment will be modest.

そこでまず最初に、予想の変化によって雇用が長期の局面へ移行して、もはや予想のさらなる変化によって雇用が乱れたり中断したりしないようになるまでの過 程を考えてみよう。初めに、我々はその予想の変化によって新たな長期雇用が以前の長期雇用よりも大きくなる場合を考えてみよう。そうすると、普通、最初に その予想の変化によって大きな影響を受けるのは投入率、即ち新たな生産過程の初期段階に投入される労働量だろう。一方、予想の変化が起きる前に開始した生 産過程の後期段階での消費財の産出量と雇用量は、それまでと殆ど変わることがないだろう。半完成品のストックがある場合には、この結論は修正される可能性 がある。もっとも、当初の雇用の増加はささやかであるという事実は変わらないだろう。

As, however, the days pass by, employment will gradually increase. Moreover, it is easy to conceive of conditions which will cause it to increase at some stage to a higher level than the new long-period employment. For the process of building up capital to satisfy the new state of expectation may lead to more employment and also to more current consumption than will occur when the long-period position has been reached. Thus the change in expectation may lead to a gradual crescendo in the level of employment, rising to a peak and then declining to the new long-period level.

しかし、日がたつに連れて雇用は次第に上昇する。しかも、ある段階で新たな長期雇用より高いレベルまで雇用が上昇するような事態も容易に想像できる。とい うのは、新たな予想を満たすために資本を強化する過程で、長期の局面に達する時よりも大きな雇用と現行消費の増加が同時に起きるからである。このように、 予想の変化は雇用レベルを徐々に増加させて、一度ピークに達してから、新たな長期雇用にまで下がっていくのである。

The same thing may occur even if the new long-period level is the same as the old, if the change represents a change in the direction of consumption which renders certain existing processes and their equipment obsolete. Or again, if the new long-period employment is less than the old, the level of employment during the transition may fall for a time below what the new long-period level is going to be. Thus a mere change in expectation is capable of producing an oscillation(変動) of the same kind of shape as a cyclical movement, in the course of working itself out. It was movements of this kind which I discussed in my Treatise on Money in connection with the building up or the depletion of stocks of working and liquid capital consequent on change.

たとえ新たな長期雇用が以前の長期雇用と同レベルであっても、これと同じことが起きる。それは起こった変化が、生産過程とその設備を時代遅れにするような 消費の変化である場合である。あるいはまた、もし新たな長期雇用が以前の長期雇用よりも低い場合には、移行期間の雇用レベルが新たな長期雇用のレベルより も一時的に下回ることもある。つまり、たった一度の予想の変化も、それが効果を発揮し終えるまでには、周期的変動と同じような変動が起きるのである。予想 の変化によって起きる運転資本ストックと流動資本ストックの増減に関して『貨幣論』の中で私が述べたのはこの種の変動なのである。

An uninterrupted process of transition, such as the above, to a new long-period position can be complicated in detail. But the actual course of events is more complicated still. For the state of expectation is liable to constant change, a new expectation being superimposed long before the previous change has fully worked itself out; so that the economic machine is occupied at any given time with a number of overlapping activities, the existence of which is due to various past states of expectation.

このように、新たな長期の局面への連続的な移行過程は詳しく見ると非常に複雑なようだが、実際の進展はさらに複雑である。というのは、予想の状態は常に変 化しやすいものなので、その前の変化が効果を発揮し終える前に新たな予想が始まってしまうからである。経済システムの中ではいつでも多くの動きが同時進行 しているが、それらの動きは過去の様々な予想によって始まったものなのである。

II

This leads us to the relevance of this discussion for our present purpose. It is evident from the above that the level of employment at any time depends, in a sense, not merely on the existing state of expectation but on the states of expectation which have existed over a certain past period. Nevertheless past expectations, which have not yet worked themselves out, are embodied in the to-day's capital equipment with reference to which the entrepreneur has to make to-day's decisions, and only influence his decisions in so far as they are so embodied. It follows, therefore, that, in spite of the above, to-day's employment can be correctly described as being governed by to-day's expectations taken in conjunction with to-day's capital equipment.

第2節
 
  ここでこれまでの議論が我々の現在の目的につながってくる。いつの時点の雇用レベルも現在の予想の状態だけでなく過去のある期間に存在した予想の状態にも 依存していることが、いまの議論で明らかだろう。とはいえ、過去の予想がその効果をまだ発揮し終えていないとしても、それは今日の資本設備の中に体現され ているのであり、その設備について企業家は今日の決断をするのである。つまり、過去の予想は今日の設備に体現されている範囲内で企業家の決断に影響するの である。したがって、これまでの複雑な議論に関わらず、結局のところ、今日の雇用を決めるものは今日の資本設備と結びついた今日の予想であると言うのが正 しいのである。

Express reference to current long-term expectations can seldom be avoided. But it will often be safe to omit express reference to short-term expectation, in view of the fact that in practice the process of revision of short-term expectation is a gradual and continuous one, carried on largely in the light of realised results; so that expected and realised results run into and overlap one another in their influence. For, although output and employment are determined by the producer's short-term expectations and not by past results, the most recent results usually play a predominant part in determining what these expectations are.

当期の長期予想をはっきりと考慮に入れることは避けられない。しかしながら、短期予想は現実にはふつう実現された結果に影響されて常にゆっくり変化し続け ており、そのため予想された結果と実現された結果が重なりあい互いに影響しあうことを考えると、短期予想ははっきり考慮に入れない方が安全だろう。という のは、産出量と雇用を決めるのは生産者の短期予想であって過去の結果ではないが、間近に起きた結果が短期予想を決めるうえで常に大きな役割を演じているか らである。

  It would be too complicated to work out the expectations de novo whenever a productive process was being started; and it would, moreover, be a waste of time since a large part of the circumstances usually continue substantially unchanged from one day to the next. Accordingly it is sensible for producers to base their expectations on the assumption that the most recently realised results will continue, except in so far as there are definite reasons for expecting a change. Thus in practice there is a large overlap between the effects on employment of the realised sale-proceeds of recent output and those of the sale-proceeds expected from current input; and producers' forecasts are more often gradually modified in the light of results than in anticipation of prospective changes.[4]

一つの生産過程が始まるたびに新たに予想を形成するのは面倒だし時間の無駄でもある。一日ごとではまわりの状況は殆ど変わることがないのが普通だからであ る。だから、生産者は変化が予想される明確な理由がない限りは、間近に実現された結果がそのまま続くと考えて自分の予想を形成するのが賢明である。つま り、当期の投入から予想される販売売上が雇用に及ぼす影響と、直近の産出物によって実現された販売売上が雇用に及ぼす影響とでは殆ど同じなのである。した がって、生産者の予想は将来の変化への予想よりは現実の結果によって徐々に変わってくるである[4]。

Nevertheless, we must not forget that, in the case of durable goods(耐久財、耐久消費財), the producer's short-term expectations are based on the current long-term expectations of the investor; and it is of the nature of(~に似ている) long-term expectations that they cannot be checked at short intervals in the light of realized results. Moreover, as we shall see in Chapter 12, where we shall consider long-term expectations in more detail, they are liable to sudden revision. Thus the factor of current long-term expectations cannot be even approximately eliminated or replaced by realised results.

それにもかかわらず、耐久消費財の場合には、生産者の短期予想は投資家の当期の長期予想にもとづいていることを忘れてはならない。そして、実現された結果 によって生産者の予想が短期的に変更されないのは、長期予想の性格から来ているのである。しかも、後に第12章で長期予想についてもっと詳しく検討すると きに見るように、長期予想は急激な変化を受けやすい。だから、当期の長期予想という要素を無視することはできないし、実現された結果によってそれを変更す ることもできないのである。

Author's Footnotes

[1]. For the method of arriving at an equivalent of these expectations in terms of sale-proceeds see footnote (3) to p. 24 above.

[2]. Daily here stands for the shortest interval after which the firm is free to revise its decision as to how much employment to offer. It is, so to speak, the minimum effective unit of economic time.

[3]. It is not necessary that the level of long-period employment should be constant, i.e. long-period conditions are not necessarily static. For example, a steady increase in wealth or population may constitute a part of the unchanging expectation. The only condition is that the existing expectations should have been foreseen sufficiently far ahead.

[4]. This emphasis on the expectation entertained when the decision to produce is taken, meets, I think, Mr Hawtrey's point that input and <employment are influenced by the>(一部のテキストで脱落) accumulation of stocks before prices have fallen or disappointment in respect of output is reflected in a realised loss relatively to expectation. For the accumulation of unsold stocks (or decline of forward orders) is precisely the kind of event which is most likely to cause input to differ from what mere statistics of the sale-proceeds of previous output would indicate if they were to be projected without criticism into the next period.

著者注

[1] 販売売上に関してこれらの予想値に相当するものに到達する方法については、上記脚注4★を見よ。

[2] ここでいう「日々」とは企業が提供する雇用量を変更するまでの最短の期間を意味する。それは、いわば経済的時間の有効な最小単位である。

[3] 長期雇用のレベルは一定不変である必要はない。長期の状況は静的であるとは限らないからである。例えば、不変な予想の一部が富や人口の順調な増加 によって維持されているかもしれない。長期雇用の唯一の条件は、現在の予想値がはるか以前から予見されていることだけなのである。

[4] 生産決定をするときの予想に関してこの点(=現実の結果による修正)を強調することは、投入と雇用は在庫の蓄積によって起きるというホートリー氏の主張と 合致していると思う。彼の意見では、価格の低下が起きる前、あるいは産出量についての予想外れが予想外の実損という形で現れる前に、投入の変化が起きると いうのである。というのは、売れ残りの在庫の蓄積(あるいは予約の減少)は、投入に変化をもたらす最も重要な出来事であり、前期の産出量から得られた販売 売上の単なる統計がそのまま無批判に次期に反映されることはないのである。


Chapter 6. The Definition of Income, Saving and Investment

第6章 所得と貯蓄と投資の定義

I. Income

  DURING any period of time an entrepreneur will have sold finished output to consumers or to other entrepreneurs for a certain sum which we will designate as A. He will also have spent a certain sum, designated by A1, on purchasing finished output from other entrepreneurs. And he will end up with a capital equipment, which term includes both his stocks of unfinished goods or working capital and his stocks of finished goods, having a value G.

第1節 所得

  企業家は完成した産出物をある期間中に消費者か他の企業家に一定の額で売り払うだろう。その値をAとする。同時に彼は他の企業家から完成した産出物を購入 するために一定の額を支払うだろう(=設備投資)。その値をA1とする。そして企業家はある資本設備を手にしてその期間を終える。資本設備には未完成品の ストックつまり運転資本(=経営資本)と完成品のストックの両方が含まれる。資本設備の値をGとする。

Some part, however, of A + G - A1 will be attributable, not to the activities of the period in question, but to the capital equipment which he had at the beginning of the period. We must, therefore, in order to arrive at what we mean by the income of the current period, deduct from A + G - A1 a certain sum, to represent that part of its value which has been (in some sense) contributed by the equipment inherited from the previous period. The problem of defining income is solved as soon as we have found a satisfactory method for calculating this deduction.

しかしながら、A+G-A1のいくつかの部分は当該期間における活動から生まれたものではなく、その期間が始まる時点で既に所有していた資本設備から生ま れたものである。だから、当期の所得と考えられるものを算出するためには、「前期から引き継がれた設備が(ある意味で)寄与している部分の価値」をA+G -A1から差し引かねばならない。所得を定義する問題は、この控除分を計算する方法を見つけさえすれば解決するのである。

There are two possible principles for calculating it, each of which has a certain significance; ― one of them in connection with production, and the other in connection with consumption. Let us consider them in turn.

これを計算するための可能な方法は二つあって、それぞれに意義がある。その一つは生産に関するものであり、もう一つのは消費に関するものである。順番に見ていこう。

(i) The actual value G of the capital equipment at the end of the period is the net result of the entrepreneur, on the one hand, having maintained and improved it during the period, both by purchases from other entrepreneurs and by work done upon it by himself, and, on the other hand, having exhausted or depreciated it through using it to produce output.

(i)期間の終わりの実際の資本設備の値Gとは、他の企業家からの購入(=A1)と自分の働きによって企業家がその期間内に資本設備を維持改良した分(=B’)から、産出物を生み出すために資本設備を消耗させてその価値を低下させた分を差し引いた結果である。

  If he had decided not to use it to produce output, there is, nevertheless, a certain optimum sum which it would have paid him to spend on maintaining and improving it. Let us suppose that, in this event, he would have spent B' on its maintenance and improvement, and that, having had this spent on it, it would have been worth G' at the end of the period. That is to say, G' - B' is the maximum net value which might have been conserved from the previous period, if it had not been used to produce A.

もし産出物を生み出すために資本設備を使わないと決めていた場合には、資本設備を維持改良するために支出すれば企業家の得になる最適な額がある。この場 合、彼は資本設備の維持改善のためにB’だけ支出したと仮定しよう。そしてこの支出の御陰でその期間の終りにはその資本設備はG’の価値になっているとし よう。すると、G’-B’は、「設備がAを生産するために使われなかった場合に前期から繰り越されたかもしない最大の純価値」ということになる。

The excess of this potential value of the equipment over G - A1 is the measure of what has been sacrificed (出費された)(one way or another) to produce A. Let us call this quantity, namely

(G' - B') - (G - A1),

which measures the sacrifice of value involved in the production of A, the user cost of A. User cost will be written U.[1] The amount paid out by the entrepreneur to the other factors of production(=他の生産要素=労働者=生産要素) in return for their services, which from their point of view is their income, we will call the factor cost of A. The sum of the factor cost F and the user cost U we shall call the prime-cost of the output A.

そして、設備のこの潜在的な価値(=前期から受け継がれた最大の資本設備の価値)がG-A1(=当期の最後に残った資本設備の価値)を上回る分が、(=前期から受け継がれた資本設備のうちで)Aを生産するために(何らかの形で)使われたものの大きさである。この数量、

(G’-B’)-(G-A1)、

即ちAを生産するために使われた価値の量を、Aの「使用費用」と呼ぶことにしよう。この「使用費用」をUと書くことにする[1]。また、企業家が生産要素 (=労働者)に対してそのサービスの対価として支払った額を、Aの「要素費用」(=F)と呼ぶことにする。この額は生産要素の側から見ると彼らの所得とな る。要素費用Fと使用費用Uとの合計を産出物Aの「主要費用」と呼ぶことにする。

We can then define the income[2] of the entrepreneur as being the excess of the value of his finished output sold during the period over his prime-cost. The entrepreneur's income, that is to say, is taken as being equal to the quantity, depending on his scale of production, which he endeavours to maximise, i.e., to his gross profit in the ordinary sense of this term;― which agrees with common sense. Hence, since the income of the rest of the community(=企業家以外の人達) is equal to the entrepreneur's factor cost, aggregate income is equal to A - U.

すると、企業家の「所得」[2]とはその期間内に販売された完成済み産出物の価格(=A)が主要費用(=F+U)を上回る額であると定義できる(=A-U -F、第3章第1節と同じ)。言い換えれば、生産規模に応じた額であり、企業家ができるだけ大きくしようと努める額でもある粗利潤(=粗利益)、言葉の通 常の意味における粗利潤こそが、企業家の所得と一致するのである。そして、このことは常識にも一致する。逆に、企業家の要素費用は企業家以外の人たちの所 得であるから、「総所得(=企業家とそれ以外の所得の合計=売上)」はA-Uなのである。

  Income, thus defined, is a completely unambiguous quantity. Moreover, since it is the entrepreneur's expectation of the excess of this quantity over his out-goings to the other(=自分以外のことなので訳では省略) factors of production which he endeavours to maximise when he decides how much employment to give to the other factors of production, it is the quantity which is causally significant for employment.

このように定義された所得は一切の曖昧さを含まない額である。企業家はこの所得(=総所得)の額が生産要素への出費(=F)を上回ることを予想するのであ る((A-U)-F>0)。この上回る分の予想値を最大にしようとして、企業家は生産要素に与える雇用量を決めるのである。したがって、この所得は雇用の 要因として非常に重要な数字なのである。

  It is conceivable, of course, that G - A1 may exceed G' - B', so that user cost will be negative. For example, this may well be the case if we happen to choose our period in such a way that input has been increasing during the period but without there having been time for the increased output to reach the stage of being finished and sold. It will also be the case, whenever there is positive investment, if we imagine industry to be so much integrated that entrepreneurs make most of their equipment for themselves. Since, however, user cost is only negative when the entrepreneur has been increasing his capital equipment by his own labour, we can, in an economy where capital equipment is largely manufactured by different firms from those which use it, normally think of user cost as being positive. Moreover, it is difficult to conceive of a case where marginal user cost associated with an increase in A, i.e. dU/dA, will be other than positive.

もちろん、G-A1がG’-B’より大きくなって使用費用(=U)がマイナス(=-Uがプラス)になる事態を想定することも可能である。例えば、期間の選 び方によっては、その期間に投入が増加しても、増加された投入が完成品となって販売される段階に達するだけの時間がない場合にはそうなる可能性がある。ま た、産業の統合(=一貫生産)が進んで企業家たちが自分の設備の大部分を自分で作るようになって(=A1がゼロになる)、投資(=A1-U)がプラスにな る場合にもそうなるだろう。しかし、使用費用がマイナスになるのは企業家が自分の資本設備を自分の働きによって増やし続けた場合だけなので、資本設備がそ れを使う会社とは別の会社によって作られる経済においては、普通は使用費用はプラスになると考えられる。さらに、Aの増加と結びついた限界使用費用、即ち dU/dAがプラスにならない場合を考えるのは難しい。

  It may be convenient to mention here, in anticipation of the latter part of this chapter, that, for the community as a whole, the aggregate consumption (C) of the period is equal to Σ(A - A1), and the aggregate investment (I) is equal to Σ(A1 - U). Moreover, U is the individual entrepreneur's disinvestment (and -U his investment) in respect of his own equipment exclusive of what he buys from other entrepreneurs. Thus in a completely integrated system (where A1 = 0) consumption is equal to A and investment to -U, i.e. to G - (G' - B'). The slight complication of the above, through the introduction of A1, is simply due to the desirability of providing in a generalised way for the case of a non-integrated system of production.

ここでこの章の後半(=第2節 貯蓄と投資)を先取りして、次のことを述べておくのは便利かもしれない。それは、社会全体にとってその期間の「総消費 (C)」はΣ(A-A1)と等しく、「総投資(I)」はΣ(A1-U)に等しいということである。さらに、Uは個々の企業家が他の企業家から購入するもの (=A1)を除いた、彼の設備についてのマイナスの投資(-Uは企業家のプラスの投資)である。つまり、完全に統合された一貫生産システム(そこではA1 =0)では、消費はAと等しく、投資は-UつまりG-(G’-B’)に等しい。上記ではA1を導入したことで多少複雑になっているが、それは単に統合され ていない生産システムのために一般的な方法を提示するほうが望ましいためである。

Furthermore, the effective demand is simply the aggregate income (or proceeds) which the entrepreneurs expect to receive, inclusive of the incomes which they will hand on to other factors of production, from the amount of current employment which they decide to give. The aggregate demand function relates various hypothetical quantities of employment to the proceeds which their outputs are expected to yield; and the effective demand is the point on the aggregate demand function which becomes effective because, taken in conjunction with the conditions of supply, it corresponds to the level of employment which maximises the entrepreneur's expectation of profit.

さらに言うなら、「有効需要」とは、簡単にいえば、企業家が供給すると決めた当期の雇用量から自分が受け取ると予想する総所得(あるいは売上)のことであ り、企業家が生産要素に渡すことになる所得も含まれている。総需要関数とは、様々に仮定した雇用量に、その雇用の産出物がもたらすと予想される売上を関連 付けるものである。したがって、有効需要とはその総需要関数上の点であり、その点が「有効」と言えるのは、供給条件と組み合わされることによって、その点 が企業家の利潤の予想値を最大化する雇用レベルを指すからである。

This set of definitions also has the advantage that we can equate the marginal proceeds (or income) to the marginal factor cost; and thus arrive at the same sort of propositions relating marginal proceeds thus defined to marginal factor costs as(= the same ...as ) have been stated by those economists who, by ignoring user cost or assuming it to be zero, have equated supply price[3] to marginal factor cost.[4]

我々はこの一連の定義のおかげで、限界売上(あるいは限界所得)を限界要素費用と等値出来るようになる。つまり我々は、上記で定義された売上(=使用費用 を含まない)の限界値を要素費用の限界値に関連付けることで、これまでの経済学者が使用費用を無視するかゼロと見なして供給価格[3]を限界要素費用に等 値させて来たのと同種の主張に到達することが出来るのである[4]。

(ii) We turn, next, to the second of the principles referred to above. We have dealt so far with that part of the change in the value of the capital equipment at the end of the period as compared with its value at the beginning which is due to the voluntary decisions of the entrepreneur in seeking to maximise his profit. But there may, in addition, be an involuntary loss (or gain) in the value of his capital equipment, occurring for reasons beyond his control and irrespective of his current decisions, on account of (e.g.) a change in market values, wastage by obsolescence or the mere passage of time, or destruction by catastrophe such as war or earthquake.

(ii)次に、上で言及した二番目の方法に移ろう。これまで我々は期間の最初と最後での資本設備の価値の変化を扱ってきた。その変化は利潤を最大にしよう とする企業家の意図的な決定によってもたらされるものであった。しかし、その他に、資本設備の価値に関しては意図せず損(あるいは得)をすることがあり、 それは当期の決定とは無関係にどうすることも出来ない理由で起こる。つまり、市場価格の変動、旧式化による損失、単なる時間の経過、戦争や地震などの災難 による破壊である。

Now some part of these involuntary losses, whilst they are unavoidable, are ― broadly speaking ― not unexpected; such as losses through the lapse of time irrespective of use, and also “normal” obsolescence which, as Professor Pigou expresses it, “is sufficiently regular to be foreseen, if not in detail, at least in the large”, including, we may add, those losses to the community as a whole which are sufficiently regular to be commonly regarded as “insurable risks”. Let us ignore for the moment the fact that the amount of the expected loss depends on when the expectation is assumed to be framed, and let us call the depreciation of the equipment, which is involuntary but not unexpected, i.e. the excess of the expected depreciation over the user cost, the supplementary cost, which will be written V. It is, perhaps, hardly necessary to point out that this definition is not the same as Marshall's definition of supplementary cost, though the underlying idea, namely, of dealing with that part of the expected depreciation which does not enter into prime-cost, is similar.

ところで、これらの意図しない損失のある部分は、確かに避け難いものではあるがたいていは予期せぬものではない。それは例えば、使用度合いに関わらず時間 の経過によって進む損失や「通常の」旧式化である。それはピグー教授の言うように「充分規則的なもので」「詳細を見通せなくても大体は予想のつくものであ り」、さらには普通「保険可能リスク」と見なされるような充分規則的な社会全体の損失が含まれる。しばらく、予期された損失の量が予想形成の時期に依存す るという事実を無視することにしよう。そして不本意ではあるが予期せぬものではない設備の減価(それは予想される減価が「使用費用」(U)を超える分であ るが)を「補足費用(=補足的費用=固定的減価償却)」と呼んでVで表わすことにしよう。おそらくこの定義がマーシャルの「補足費用」の定義と異なるのは 指摘するまでもない。もっとも、その基礎となる考え方、つまり予想された減価償却のうち主要費用には含まれないもの(=固定的減価償却費、使用しない設備 の減価)を扱うという考え方は似ていると言える。

  In reckoning, therefore, the net income and the net profit of the entrepreneur it is usual to deduct the estimated amount of the supplementary cost from his income and gross profit as defined above. For the psychological effect on the entrepreneur, when he is considering what he is free to spend and to save, of the supplementary cost is virtually the same as though it came off his gross profit. In his capacity as a producer deciding whether or not to use the equipment, prime-cost and gross profit, as defined above, are the significant concepts. But in his capacity as a consumer the amount of the supplementary cost works on his mind in the same way as if it were a part of the prime-cost. Hence we shall not only come nearest to common usage but will also arrive at a concept which is relevant to the amount of consumption, if, in defining aggregate net income, we deduct the supplementary cost as well as the user cost, so that aggregate net income is equal to A - U - V.

したがって、企業家の「純所得」と「純利潤」を計算するときには、上記で定義された所得(=A-U)と粗利潤(=A-U-F)から推定の補足費用を差し引 くのが普通である。というのは、企業家が支出したり貯蓄したりできる額を考えるときには、補足費用は心理的にはその分だけ粗利潤から引かれているのと同じ ことだからである。企業家が「生産者」の立場に立って資本設備を使用するかどうかを決めるときには、上記で定義した主要費用(=U+F)と粗利潤が重要な ものとなる。しかし、企業家が「消費者」の立場に立つ場合には、補足費用(=V 、固定的減価償却費)は主要費用の一部であるとする気持ちになる。だから、我々は慣用に出来るだけ近づくだけでなく、消費額を決定する一つの概念(=純所 得)に到達するためには、「純所得」の総額を定義するときに、売上から使用費用(=∪、原材料費+可変的減価償却費)だけでなく補足費用(=V 、固定的減価償却)も差し引かねばならないのである。つまり「純所得」の総額はA-U-Vに等しくなるのである。

There remains the change in the value of the equipment, due to unforeseen changes in market values, exceptional obsolescence or destruction by catastrophe, which is both involuntary and ― in a broad sense ― unforeseen. The actual loss under this head, which we disregard even in reckoning net income and charge to capital account, may be called the windfall loss.

設備の価値の変化のうちで最後に残るものは、予期せぬ市場価格の変化、例外的な旧式化、災害による破壊である。最後のものは不本意な変化であると同時に広 い意味で予期せぬ変化である。この項目に入る実際の損失は「純所得」の計算には含めずに「資本勘定(=資本収支)」で扱うものであり「偶発的損失(=意外 の損失)」と呼ばれるのが相応しい。

The causal significance of net income lies in the psychological influence of the magnitude of V on the amount of current consumption, since net income is what we suppose the ordinary man to reckon his available income to be when he is deciding how much to spend on current consumption. This is not, of course, the only factor of which he takes account when he is deciding how much to spend. It makes a considerable difference, for example, how much windfall gain or loss he is making on capital account. But there is a difference between the supplementary cost and a windfall loss in that changes in the former are apt to affect him in just the same way as changes in his gross profit. It is the excess of the proceeds of the current output over the sum of the prime-cost and the supplementary cost which is relevant to the entrepreneur's consumption; whereas, although the windfall loss (or gain) enters into his decisions, it does not enter into them on the same scale ― a given windfall loss does not have the same effect as an equal supplementary cost.

経済的要因としての純所得の意味は、V(=補足費用)の大きさが当期の消費額の大きさに与える心理的影響にある。「純所得」とは一般の人の場合なら当期の 消費にどれだけ支出できるかを決めるときに自由にできると見做す額であるからである。もちろん、これだけが支出を決めるときに考慮する唯一の要素ではな い。例えば、企業家が資本勘定にどれだけ偶発的な損得を含めるかによって非常に大きな違いがうまれる。しかし、補足費用と偶発的損失の間には大きな違いが ある。補足費用の変化は粗利潤の変化と同じような影響を企業家に与えるからである。そして、企業家の消費にとって重要なのは、当期の産出物から生まれた売 上から主要費用と補足費用の合計を差し引いた額なのである。それに対して、偶発的損失(あるいは利潤)は企業家の決定に影響するものの、補足費用と同じよ うに影響することはない。偶発的な損失は同額の補足費用と同じ影響力を持たないのである。

We must now recur, however, to the point that the line between supplementary costs and windfall losses, i.e. between those unavoidable losses which we think it proper to debit to income account and those which it is reasonable to reckon as a windfall loss (or gain) on capital account, is partly a conventional or psychological one, depending on what are the commonly accepted criteria for estimating the former. For no unique principle can be established for the estimation of supplementary cost, and its amount will depend on our choice of an accounting method. The expected value of the supplementary cost, when the equipment was originally produced, is a definite quantity. But if it is re-estimated subsequently, its amount over the remainder of the life of the equipment may have changed as a result of a change in the meantime in our expectations; the windfall capital loss being the discounted value(=減価、割引価値、現在価値、将来含まれる利息を割り引いた値) of the difference between the former and the revised expectation of the prospective series of U + V.

しかしながら、我々は次の点に立ち戻らねばならない。即ち、補足費用と偶発的損失との間の線引き、つまり、所得勘定の借り方につけるのが相応しいと思われ る避け難い損失と、資本勘定に偶発的損失(あるいは利潤)として計上すべきものとの間の線引きは、慣習的であるか心理的なものであって、一般に行われてい る補足費用の算定基準に依存しているのである。というのは、補足費用を算定する方法を一つに設定することは不可能なので、補足費用の額は会計のやり方次第 で違ってくるからである。また、設備が最初に作られた時に予想された補足費用の額は明確であるが、その後、その額が計算し直されると、設備の残りの寿命の 期間についての補足費用の額は、それまでの期間の我々の予想の変化によって、変わってしまう可能性がある。それに対して、資本の偶発的損失は、予想される U+Vの組み合わせの最初の予想額と変更された予想額との差額の割引価値(=現在価値、将来の価値を利率分割り引いた現在の値)である。

  It is a widely approved principle of business accounting, endorsed by the Inland Revenue authorities, to establish a figure for the sum of the supplementary cost and the user cost when the equipment is acquired and to maintain this unaltered during the life of the equipment, irrespective of subsequent changes in expectation. In this case the supplementary cost over any period must be taken as the excess of this predetermined figure over the actual user cost. This has the advantage of ensuring that the windfall gain or loss shall be zero over the life of the equipment taken as a whole. But it is also reasonable in certain circumstances to recalculate the allowance for supplementary cost on the basis of current values and expectations at an arbitrary accounting interval, e.g. annually. Business men in fact differ as to which course they adopt. It may be convenient to call the initial expectation of supplementary cost when the equipment is first acquired the basic supplementary cost, and the same quantity recalculated up to date on the basis of current values and expectations the current supplementary cost.

一つ広く認められた企業会計の方法がある。英国の内国歳入庁の権威筋によって認められている方法で、それは設備を入手した時に使用費用と補足費用の合計 (=U+V)を設定して、その後の予想の変化に関わらず、設備の寿命が続く限りこの数字を変更しないという方法である。この場合には、どの期間に対する補 足費用(=V)も、あらかじめ決められたこの数字から実際の使用費用(=U)を差し引いた残りと見なされなければならない。こうすれば設備の寿命の期間を 通じて偶発的な損得(U+Vの変化)をゼロに保てるという利点がある。しかし、ある環境においては、補足費用に対する引当金を任意の間隔を置いて(つまり 1年毎に)現在の価値と予想に基づいて計算し直すほうが合理的である。実業家が実際どの方法を採用するかは様々である。設備を最初に入手したときの補足費 用の初めの予測を「基本的補足費用」と呼び、現在の価値と予測に基づいて再計算した値を「当期補足費用」と呼ぶのが便利かもしれない。

Thus we cannot get closer to a quantitative definition of supplementary cost than that it comprises those deductions from his income which a typical entrepreneur makes before reckoning what he considers his net income for the purpose of declaring a dividend (in the case of a corporation) or of deciding the scale of his current consumption (in the case of an individual). Since windfall charges(=changesの誤植かも。以後は windfall changesとなっている) on capital account are not going to be ruled out of the picture, it is clearly better, in case of doubt, to assign an item to capital account, and to include in supplementary cost only what rather obviously belongs there. For any overloading of the former can be corrected by allowing it more influence on the rate of current consumption than it would otherwise have had.

つまり、補足費用の量的な定義に関しては、(企業の場合には)配当金を公表する目的で(個人の場合には)当期の消費額を決定する目的で、企業家が自分の純 所得(=A-U-V)を計算する前に所得(=A-U)から控除する額は補足費用に含まれるということ以上に詳しい定義はできないのである。偶発的変化は資 本勘定で扱うことがやめられない以上、疑わしい項目は資本勘定に回して、補足費用の中身はそこに含まれることが明白なものだけにするが望ましい。というの は、資本勘定に含める項目が多くなりすぎても、資本勘定が増えたことで普段よりも当期の消費高が影響を受けるだけだからである。

  It will be seen that our definition of net income comes very close to Marshall's definition of income, when he decided to take refuge in the practices of the Income Tax Commissioners and ― broadly speaking ― to regard as income whatever they, with their experience, choose to treat as such. For the fabric of their decisions can be regarded as the result of the most careful and extensive investigation which is available, to interpret what, in practice, it is usual to treat as net income. It also corresponds to the money-value of Professor Pigou's most recent definition of the National Dividend.[5]

我々の純所得の定義がマーシャルの所得の定義と非常によく似ていることはすぐに分かるだろう。簡単に言うと、彼は所得税徴税官の習慣を使って、徴税官が自 分の経験から所得と見做すものは全て所得と見做すことにしたのである。徴税官の決め方は最も慎重かつ広範な調査にもとづくものであり、それはふつう純所得 として扱われるべきものが何であるかを理解するのに格好の調査である。我々の定義はまたピグー教授が最近定義した「国民分配分」の貨幣価値と符合する。

  It remains true, however, that net income, being based on an equivocal criterion which different authorities might interpret differently, is not perfectly clear-cut. Professor Hayek, for example, has suggested that an individual owner of capital goods might aim at keeping the income he derives from his possession constant, so that he would not feel himself free to spend his income on consumption until he had set aside sufficient to offset any tendency of his investment-income to decline for whatever reason.[6] I doubt if such an individual exists; but, obviously, no theoretical objection can be raised against this deduction as providing a possible psychological criterion of net income. But when Professor Hayek infers that the concepts of saving and investment suffer from a corresponding vagueness, he is only right if he means net saving and net investment. The saving and the investment, which are relevant to the theory of employment, are clear of this defect, and are capable of objective definition, as we have shown above.

もっとも、純所得は学者によっては解釈の異なる曖昧な基準にもとづいているので、完全に明確なものにならないのは仕方がない。例えば、ハイエク教授の考え では、資本財の所有者は自分の財産から得られる所得を一定にすることを目指しているので、投資所得が減らないように貯えを充分にするまでは所得を消費にど んどん回す気にはならないらしい[6]。私にはそんな人が実際にいるとは思えないが、純所得の心理学的な基準をもたらすこの償却費を論理的に否定すること はできないのだ。しかし、ハイエク教授が、貯蓄と投資の概念にもこれと同じ曖昧さがあると言っていることについては、それが「純貯蓄」と「純投資」を意味 するのでなければ、彼は間違っている。雇用理論にとって重要な意味を持つ「貯蓄」と「投資」には曖昧さは存在しないし、上で示したように客観的な定義が可 能なのである。

  Thus it is a mistake to put all the emphasis on net income, which is only relevant to decisions concerning consumption, and is, moreover, only separated from various other factors affecting consumption by a narrow line; and to overlook (as has been usual) the concept of income proper, which is the concept relevant to decisions concerning current production and is quite unambiguous.

  つまり、「純所得」ばかりを強調して本来の所得の概念を(よくあるように)無視するのは間違いである。純所得は消費の決定にしか関わらないものであり、消 費に影響する他の様々な要素と大きな違いはない。むしろ当期の生産の決定に関わる概念である本来の「所得」には全く曖昧なところがないのである。

  The above definitions of income and of net income are intended to conform as closely as possible to common usage. It is necessary, therefore, that I should at once remind the reader that in my Treatise on Money I defined income in a special sense. The peculiarity in my former definition related to that part of aggregate income which accrues to the entrepreneurs, since I took neither the profit (whether gross or net) actually realised(利益を得る) from their current operations nor the profit which they expected when they decided to undertake their current operations, but in some sense (not, as I now think, sufficiently defined if we allow for the possibility of changes in the scale of output) a normal or equilibrium profit; with the result that on this definition saving exceeded investment by the amount of the excess of normal profit over the actual profit.

  上記の所得と純所得の定義は出来るだけ慣用に合わせることを目指している。だから、読者には『貨幣論』のなかで私が行った所得の定義が特殊なものだったこ とを思い出してもらう必要がある。以前の私の特殊な定義は、総所得のうちで企業家が手にする部分だけについてのものだったからである。というのは私が取り 上げたのは、現在の事業から実際に実現された利潤(純利潤にしろ粗利潤にしろ)でもなく、現在の事業を行う決定をしたときに予想した利潤でもなく、いわば 正常利潤(=「通常利潤」「正常報酬」)あるいは均衡利潤(これはいま考えると産出量の変化の可能性を含めた充分な定義にはなっていなかった)だったから である。その結果、この定義では、正常利潤が実利潤を上回る分だけ貯蓄が投資を上回ることになっていた。

  I am afraid that this use of terms has caused considerable confusion, especially in the case of the correlative use of saving; since conclusions (relating, in particular, to the excess of saving over investment), which were only valid if the terms employed were interpreted in my special sense, have been frequently adopted in popular discussion as though the terms were being employed in their more familiar sense. For this reason, and also because I no longer require my former terms to express my ideas accurately, I have decided to discard them ― with much regret for the confusion which they have caused.

この用語の使い方は、特に貯蓄について使用される場合には、かなり混乱を引き起こしたのではないかと思う。というのは、あそこでの様々な結論(特に貯蓄が 投資を上回る分に関する結論)は、私が使った専門用語を私だけの特別な意味で解釈して初めて意味があるのに、それがまるで一般的な意味で使われているかの ように、多くの議論の中に引用されたからである。そのために、私はそれらの用語を使うのを止めることにした。また、私の考えを正確に表わすのに以前の用語 を使う必要はなくなっている。それらの用語が引き起こした混乱を私は非常に後悔している。

II. Saving and Investment

  Amidst the welter(混乱) of divergent(異なる) usages of terms, it is agreeable to discover one fixed point. So far as I know, everyone is agreed that saving means the excess of income over expenditure on consumption. Thus any doubts about the meaning of saving must arise from doubts about the meaning either of income or of consumption. Income we have defined above. Expenditure on consumption during any period must mean the value of goods sold to consumers during that period, which throws us back to the question of what is meant by a consumer-purchaser. Any reasonable definition of the line between consumer-purchasers and investor-purchasers will serve us equally well, provided that it is consistently applied. Such problem as there is, e.g. whether it is right to regard the purchase of a motor-car as a consumer-purchase and the purchase of a house as an investor-purchase, has been frequently discussed and I have nothing material to add to the discussion.

第2節 貯蓄と投資

  専門用語の様々な用法が混乱している中に一つ不動な点を発見するのは気持のいいことである。私の知る限り、「貯蓄」が所得から消費支出を差し引いたものを 意味することは誰も異論のないところである。つまり、「貯蓄」の意味に疑いが生まれるとすれば、それは必ず「所得」か「消費」の意味に対する疑問からであ る。我々は「所得」については上で定義した。確かに、ある期間における消費支出とはその期間に消費者に販売された財の価格を意味している。しかし、この定 義は我々を消費者としての買い手とは何を意味するかという問題に引き戻す。消費者としての買い手と投資者としての買い手を区別する線引きの定義がもし合理 的で一貫して適用されるものなら、充分我々に役立ってくれる。このような問題、例えば、自動車を買うことは消費者が買うと見做すべきか、家を買うことは投 資家が買うと見做すべきかという問題は、しばしば議論の対象になってきたが、この議論に対して付け加える材料は私にはない。

The criterion must obviously correspond to where we draw the line between the consumer and the entrepreneur. Thus when we have defined A1 as the value of what one entrepreneur has purchased from another, we have implicitly settled the question. It follows that expenditure on consumption can be unambiguously defined as Σ(A - A1), where ΣA is the total sales made during the period and ΣA1 is the total sales made by one entrepreneur to another. In what follows it will be convenient, as a rule, to omit Σ and write A for the aggregate sales of all kinds, A1 for the aggregate sales from one entrepreneur to another and U for the aggregate user costs of the entrepreneurs.

この判断基準は明らかに消費者と企業家の間の線引きと一致しなければならない。つまり、企業家が他の企業家から購入した物の価格をA1と定義したとき、我 々は暗黙裡にこの問題に決着を付けたことになる。そこから、消費支出はΣ(A-A1)と明確に定義できるのである。ここでΣAはその期間内に行われた全販 売であり、ΣA1は企業家が別の企業家に対して行った全購入を意味する。以下においては便宜のために、概してあらゆる種類の販売の総額はΣを省略してAと 書き、企業家から別の企業家への販売の総額をA1と書き、企業家の使用費用の総額をUと書くことにする。

  Having now defined both income and consumption, the definition of saving, which is the excess of income over consumption, naturally follows. Since income is equal to A - U and consumption is equal to A - A1, it follows that saving is equal to A1 - U. Similarly, we have net saving for the excess of net income over consumption, equal to A1 - U - V.

  既に「所得」と「消費」の両方を定義しおえたからには、所得から消費を引いた余りである「貯蓄」の定義は当然次のようになる。所得はA-Uと等しく、消費 はA-A1に等しいから、ここから貯蓄はA1-Uと等しいことになる。同様にして、「純所得」(=A-U-V)から消費(=A-A1)を差し引いた「純貯 蓄」は、A1-U-Vに等しくなる。

  Our definition of income also leads at once to the definition of current investment. For we must mean by this the current addition to the value of the capital equipment which has resulted from the productive activity of the period. This is, clearly, equal to what we have just defined as saving. For it is that part of the income of the period which has not passed into consumption. We have seen above that as the result of the production of any period entrepreneurs end up with (1)having sold finished output having a value A and with (2)a capital equipment which has suffered a deterioration measured by U (or an improvement measured by -U where U is negative) as a result of having produced and parted with A,after allowing for(=訳さない) purchases A1 from other entrepreneurs.

  また、我々の所得の定義からはただちに当期の投資の定義を導くことが出来る。というのは、「当期の投資」とは資本設備の価値への追加を意味する以外にない からである。そしてその追加はこの期間の生産活動の結果なのである。これは明らかに我々が今しがた貯蓄と定義したものと等しい。というのは、それはこの期 間の所得のうちで消費に回されなかったものだからである。我々が上で見たように、ある期間の生産を終えた企業家は最後には、価値がAの完成産出物を販売し ており、価値がUだけ減少(あるいはUがマイナスのときは-Uだけ改善)した資本設備をもっている。この減価は他の企業家からのA1の購入後に産出物Aを 生産して手放した結果である。

During the same period finished output having a value A - A1 will have passed into consumption. The excess of A - U over A - A1, namely A1 - U, is the addition to capital equipment as a result of the productive activities of the period and is, therefore, the investment of the period. Similarly A1 - U - V, which is the net addition to capital equipment, after allowing for normal impairment in the value of capital (1)apart from(=単なるfromと同じ) its being used and (2)apart from windfall changes in the value of the equipment chargeable to capital account, is the net investment of the period.

これと同じ期間の間にA-A1の価値を持つ完成産出物が消費に移される。A-U(=所得)がA-A1(=消費)上回る分、即ちA1-U(=貯蓄)が、その 期間の生産活動の結果としての資本設備への追加であり、それゆえこの期間の投資となる。同様にして、A1-U-V(=純貯蓄)、即ち資本設備に対する純追 加がその期間の「純投資」である。この場合、資本勘定に計上される設備価値の偶発的変化による減価(=V)と、使用による資本価値の通常の減価(=U)が 考慮されているのである。

Whilst, therefore, the amount of saving is an outcome of the collective behaviour of individual consumers and the amount of investment of the collective behaviour of individual entrepreneurs, these two amounts are necessarily equal, since each of them is equal to the excess of income over consumption. Moreover, this conclusion in no way depends on any subtleties or peculiarities in the definition of income given above. Provided it is agreed that income is equal to the value of current output, that current investment is equal to the value of that part of current output which is not consumed, and that saving is equal to the excess of income over consumption ― all of which is conformable both to common sense and to the traditional usage of the great majority of economists ― the equality of saving and investment necessarily follows.

したがって、貯蓄量は個々の消費者の集団的行動の結果であり、投資量は個々の企業家の集団的行動の結果であるにも関わらず、この二つの額は必然的に一致す る。というのは、そのどちらもが所得が消費を上回る額だからである。さらに、この結論は決して上記の所得の定義の細かい点や独自な点に左右されることはな い。所得は当期の産出物の価格に等しく、投資は当期の産出物のうちで消費されない部分に等しく、貯蓄は所得が消費を上回る額に等しいことを認める限り(こ れらは全て常識とも大多数の経済学者の伝統的用法とも一致している)、貯蓄と投資が等しいことは必然的結果である。


  In short―

  Income = value of output = consumption + investment.
  Saving = income - consumption.
  Therefore saving = investment.

要するに、

所得=産出物の価格=消費+投資であり、
貯蓄=所得-消費である。
故に、貯蓄=投資である。

Thus any set of definitions which satisfy the above conditions leads to the same conclusion. It is only by denying the validity of one or other of them that the conclusion can be avoided.

つまり、どのような定義を採用しようと、上記の等式を満たす限り同じ結論に至るのである。
この結論を避けるには、これらの定義のどれかの有効性を否定するしかない。

The equivalence between the quantity of saving and the quantity of investment emerges from the bilateral character of the transactions between the producer on the one hand and, on the other hand, the consumer or the purchaser of capital equipment.

貯蓄量と投資量が等しいことは、一方における生産者と他方における消費者あるいは資本設備の買い手との間の取り引きが双方向的性格をもっていることから来ている。

  Income is created by the value in excess of user cost which the producer obtains for the output he has sold; but the whole of this output must obviously have been sold either to a consumer or to another entrepreneur; and each entrepreneur's current investment is equal to the excess of the equipment which he has purchased from other entrepreneurs over his own user cost. Hence, in the aggregate the excess of income over consumption, which we call saving, cannot differ from the addition to capital equipment which we call investment. And similarly with net saving and net investment. Saving, in fact, is a mere residual. The decisions to consume and the decisions to invest between them determine incomes. Assuming that the decisions to invest become effective, they must in doing so either curtail consumption or expand income. Thus the act of investment in itself cannot help causing the residual or margin, which we call saving, to increase by a corresponding amount.

所得は生産者が産出物を売って得た価格から使用費用を引いたものである。しかし、この産出物がすべて消費者か他の企業家に売られたものであるのは明らかで ある。そして、それぞれの企業家の当期の投資は、他の企業家から購入した設備から自分の使用費用を引いた額である。すると、総額において、所得から消費を 引いた分、つまり我々が貯蓄と呼ぶことのできるものは、資本設備への追加、つまり我々が投資と呼ぶことのできるものと同じ額にならざるを得ない。事実、貯 蓄は単なる余剰である。消費をする決断と投資をする決断が一緒になって所得を決めるのである。投資の決断が実行されるとすると、それは消費を切り詰めるか 所得を拡大しなければなららない。つまり、投資という行為はそれ自体で、余剰あるいは差額を同じ量だけ増やすことにならざるをえないのである。その余剰を 我々は貯蓄と呼ぶのである。

  It might be, of course, that individuals were so te^te monte'e in their decisions as to how much they themselves would save and invest respectively, that there would be no point of price equilibrium at which transactions could take place. In this case our terms would cease to be applicable, since output would no longer have a definite market value, prices would find no resting-place between zero and infinity. Experience shows, however, that this, in fact, is not so; and that there are habits of psychological response which allow of an equilibrium being reached at which the readiness to buy is equal to the readiness to sell. That there should be such a thing as a market value for output is, at the same time, a necessary condition for money-income to possess a definite value and a sufficient condition for the aggregate amount which saving individuals decide to save to be equal to the aggregate amount which investing individuals decide to invest.

もちろん、個々の人間がどれだけ貯蓄し投資するかをそれぞれ決めるときに頭に血が登って、取り引きが価格の均衡をもたらさないことは考えられる。この場合 には、我々の用語は適用できなくなる。というのは、産出物はもはや明確な市場価格を持たなくなり、価格はゼロから無限大の間をさまようことになるからであ る。しかし、経験から実際にはこんなことは起こらないことを我々は知っている。むしろ、心理的な反応がいつも起こって、売りたい気持と買いたい気持が一致 する均衡点に到達するようになっているのである。産出物に対する市場価格というものが存在するということは、名目所得が明確な値をもつための必要条件であ るだけでなく、貯蓄する個々人が貯蓄しようとする総額と、投資する個々人が投資しようとする総額が等しくなるための十分条件でもあるのである。

Clearness of mind on this matter is best reached, perhaps, by thinking in terms of decisions to consume (or to refrain from consuming) rather than of decisions to save. A decision to consume or not to consume truly lies within the power of the individual; so does a decision to invest or not to invest. The amounts of aggregate income and of aggregate saving are the results of the free choices of individuals whether or not to consume and whether or not to invest; but they are neither of them capable of assuming an independent value resulting from a separate set of decisions taken irrespective of the decisions concerning consumption and investment. In accordance with this principle, the conception of the propensity to consume will, in what follows, take the place of the propensity or disposition to save.

この問題で頭をすっきりさせる一番よい方法は、恐らくは貯蓄する決断について考えるよりも消費するかしないの決断について考えることである。消費をするか しないを決めることはまさに個人の力で出来ることである。投資するしないの決断も同様である。総所得と総貯蓄の額は、消費と投資に関する個人の自由な選択 の結果である。しかしながら、総所得と総貯蓄の額がそれぞれ独自の値を持つことはない。つまり、総所得と総貯蓄の額は、消費と投資に関する決断とは無関係 に行われた個別の決断の結果であることはないのである。この原則にしたがって、以下においては、消費性向の概念が貯蓄性向や貯蓄傾向の代わりをすることに なる。

Author's Footnotes

[1]. Some further observations on user cost are given in an appendix to this chapter.

[2]. As distinguished from his net income which we shall define below.

[3]. Supply price is, I think, an incompletely defined term, if the problem of defining user cost has been ignored. The matter is further discussed in the appendix to this chapter, where I argue that the exclusion of user cost from supply price, whilst sometimes appropriate in the case of aggregate supply price, is inappropriate to the problems of the supply price of a unit of output for an individual firm.

[4]. For example, let us take Zw = φ(N), or alternatively Z = W. φ(N)(=ピリオドは掛け算を表す) as the aggregate supply function (where W is the wage-unit and W.Zw = Z). Then, since the proceeds of the marginal product is equal to the marginal factor-cost at every point on the aggregate supply curve, we have

ΔN = ΔAw - ΔUw = ΔZw = Δφ(N),

that is to say φ'(N) = 1; provided that factor cost bears a constant ratio to wage-cost, and that the aggregate supply function for each firm (the number of which is assumed to be constant) is independent of the number of men employed in other industries, so that the terms of the above equation, which hold good for each individual entrepreneur, can be summed for the entrepreneurs as a whole. This means that, if wages are constant and other factor costs are a constant proportion of the wages-bill, the aggregate supply function is linear with a slope given by the reciprocal of the money-wage.

[5]. Economic Journal, June 1935, p. 235.

[6]. “The Maintenance of Capital”, Economica, August 1935, p. 241 et seq.

著者注

[1]  使用費用についてのさらなる若干の考察がこの章の付録で行われている。

[2]  それに対する「純所得」については後で定義するだろう。

[3]  「供給価格」は、使用費用を定義する問題が無視されている限り、充分に定義された用語とは言えないと思われる。この問題はこの章の付録で詳しく議論され る。そこで私は、供給価格から使用費用を除外するのは、総供給価格の場合に適切なことであるが、個別の企業に対する産出物1単位の供給価格を問題にすると きには適切ではないと主張している。

[4]  例として、総供給関数としてZw=φ(N)あるいはZ=W・φ(N)を考える(ここでWは単位賃金でありW・Zw=Zである)(Zw=Z/W=労働時 間)。すると、限界生産の売上は、総供給曲線のあらゆる点で、限界要素費用と等しくなる(→ΔA-ΔU=W・ΔN)ので、 

ΔN=ΔAw-ΔUw=ΔZw=Δφ(N)(=Zは使用費用を含まない売上)

が成立する。すなわち、φ’(N)=1である(←Δφ(N)=ΔNからdφ(N)/dN=dN/dN=1)。但し、要素費用と賃金費用(=初出)の比率は 一定とし、それぞれの企業の総供給関数は他の産業での雇用人数から独立であるため、この等式の各項は個々の企業にとって有効であるだけでなく、それぞれの 総計は企業全体にとって有効なものとする。これは、賃金が一定で、他の要素費用と総賃金費用の比率も一定の場合には、総供給関数は直線となり、その勾配は 名目賃金の逆数によって与えられる(=名目賃金に反比例する)ことを意味する。(=『コンメンタール』p123以下では、この注は難解である上に間違って いると言われている。)

[5]  『エコノミック・ジャーナル』(1935年7月235頁)

[6]  「資本の維持」(『エコノミカ』1935年8月241頁以下)

Appendix on User Cost

付録、使用費用について

I

  USER cost has, I think, an importance for the classical theory of value which has been overlooked. There is more to be said about it than would be relevant or appropriate in this place. But, as a digression, we will examine it somewhat further in this appendix.

第1節

  使用費用はこれまで見落とされてきたが古典派の価格理論にとって重要なものだと思われる。使用費用については、所得の定義とは関係ないこともあるし、ここで語るにはふさわしくないが、脱線して、この付録で詳しく検討してみよう。

  An entrepreneur's user cost is by definition equal to

A1 + (G' - B') - G,

where A1 is the amount of our entrepreneur's purchases from other entrepreneurs, G the actual value of his capital equipment at the end of the period, and G' the value it might have had at the end of the period if he had refrained from using it and had spent the optimum sum B' on its maintenance and improvement. Now G - (G' - B'), namely the increment in the value of the entrepreneur's equipment beyond the net value which he has inherited from the previous period, represents the entrepreneur's current investment in his equipment and can be written I. Thus U, the user cost of his sales-turnover A, is equal to A1 - I where A1 is what he has bought from other entrepreneurs and I is what he has currently invested in his own equipment. A little reflection will show that all this is no more than common sense. Some part of his outgoings to other entrepreneurs is balanced by the value of his current investment in his own equipment, and the rest represents the sacrifice which the output he has sold must have cost him over and above the total sum which he has paid out to the factors of production.

  企業家の使用費用は定義としては

A1+(G’-B’)-G (=上記では(G’-B’)-(G-A1))

と等しい。ここでA1は我らが企業家による他の企業家からの購入量(=原材料費)であり、Gはこの期間の終りにおける彼の資本設備の実際の価値であり、 G’はもし設備を使わずに設備の維持改善に最適な額B’を支出していた場合に期間の終りに設備がもちえた価値である。さてG-(G’-B’)は企業家の設 備の価値(=G)が前期から受け継いだ純価値(=G’-B’)を上回る増加分で、企業家による設備に対する当期の投資を表しており、Iと書くことが出来 る。すると、販売売上Aの使用費用UはA1-Iに等しい(I=A1-Uは既出)。ここでA1は他の企業家からの購入であり、Iは当期に自分の設備に行った 投資である。少し考えればこれが常識以外の何物でもないことはすぐに分かる。他の企業家への支出(=A1)の一部は自分の設備に対する当期の投資(=- I)で相殺されて、その残り(=∪)は彼が売った産出物の製造にかかった経費のうちで生産要素へ支払った額を超える分(=原材料費+可変的減価償却費)を 表しているからである。

  If the reader tries to express the substance of this otherwise, he will find that its advantage lies in its avoidance of insoluble (and unnecessary) accounting problems. There is, I think, no other way of analysing the current proceeds of production unambiguously. If industry is completely integrated or if the entrepreneur has bought nothing from outside, so that A1 = 0, the user cost is simply the equivalent of the current disinvestment involved in using the equipment; but we are still left with the advantage that we do not require at any stage of the analysis to allocate the factor cost between the goods which are sold and the equipment which is retained. Thus we can regard the employment given by a firm, whether integrated or individual, as depending on a single consolidated decision ― a procedure which corresponds to the actual interlocking character of the production of what is currently sold with total production.

もしこれを読む人がこれと同じ事を別のやり方で表わそうとすれば、このやり方のお陰で会計上の解決不可能な(そして不必要な)問題に関わらずに済むことに 気づくだろう。私が思うに、当期の生産売上を曖昧さを残さずに分析する方法はこれ以外にないのである。もし産業が完全に統合されて企業家がよそからは何も 購入せず、その結果A1=0となる場合は、使用費用は単に設備の使用によって生じる当期のマイナス投資である。しかし、分析のどの段階でも、要素費用を販 売された製品と維持された設備の間に割り振る必要がないという利点は残る。つまり我々は、企業が統合されていようがいまいが、企業の与える雇用は一つの統 一された決定(=使用費用を考えるやり方)によって行われると見ることが出来る。こうしたやり方こそ、当期に販売された物の生産が全生産過程(=販売され なかった物を含む)と実際に絡み合っているという性質とよく呼応しているのである。

  The concept of user cost enables us, moreover, to give a clearer definition than that usually adopted of the short-period supply price of a unit of a firm's saleable output. For the short-period supply price is the sum of the marginal factor cost and the marginal user cost.

  さらに、使用費用の概念のおかげで、我々はある企業の販売可能な産出物1単位の短期供給価格に関して普通採用されている定義よりも明確な定義が得られる。というのは、短期供給価格は限界要素費用と限界使用費用の合計だからである。

  Now in the modern theory of value it has been a usual practice to equate the short-period supply price to the marginal factor cost alone. It is obvious, however, that this is only legitimate if marginal user cost is zero or if supply-price is specially defined so as to be net of marginal user cost, just as I have defined (Chapter 3) “proceeds” and “aggregate supply price” as being net of aggregate user cost. But, whereas it may be occasionally convenient in dealing with output as a whole to deduct user cost, this procedure deprives our analysis of all reality if it is habitually (and tacitly) applied to the output of a single industry or firm, since it divorces the “supply price” of an article from any ordinary sense of its “price”; and some confusion may have resulted from the practice of doing so. It seems to have been assumed that “supply price” has an obvious meaning as applied to a unit of the saleable output of an individual firm, and the matter has not been deemed to require discussion.

  ところで、現在の価格理論では短期供給価格は限界要素費用だけに等しいとするのが普通の習慣となっている。しかし、これが正しいのは、限界使用費用がゼロ である場合か、供給価格を限界使用費用を含めずに特別に定義した場合だけであるのは明らかである。これは(第3章注3)「売上」と「総供給価格」を総使用 費用を含めず定義した私のやり方と同じである。時には全体としての産出物を使用費用を含めずに扱うのが便利かもしれないが、こんな事をもし習慣的に(そし て暗黙に)単独の産業や企業の産出物に対して適用していると、我々の分析から現実味が全く失われてしまう。なぜなら、それによってある商品の「供給価格」 が普通の意味での「価格」から離れてしまうからである。また使用費用を含めない習慣から混乱さえ生まれてきたかもしれない。個々の企業の販売可能な単位産 出物に適用される「供給価格」の意味は明々白々だと思われてきたので、この問題を議論する必要はないと思われてきたのである。

Yet the treatment both of what is purchased from other firms and of the wastage of the firm's own equipment as a consequence of producing the marginal output involves the whole pack of perplexities which attend the definition of income. For, even if we assume that the marginal cost of purchases from other firms involved in selling an additional unit of output has to be deducted from the sale-proceeds per unit in order to give us what we mean by our firm's supply price, we still have to allow for the marginal disinvestment in the firm's own equipment involved in producing the marginal output. Even if all production is carried on by a completely integrated firm, it is still illegitimate to suppose that the marginal user cost is zero, i.e. that the marginal disinvestment in equipment due to the production of the marginal output can generally be neglected.

ところが、他企業から購入と、限界産出物を生産した結果としての企業設備の消耗の両方を扱うのは、所得を定義するのと同じくらい複雑なことなのである。と いうのは、我々の意味する企業の供給価格を得るためには、産出物の追加1単位の販売に含まれる他企業からの購入の限界費用は、単位あたりの販売売上から差 し引かれねばならないと考えるとしても、それでもなお限界産出物の生産に含まれる企業の自己設備の限界マイナス投資(=設備の消耗)を考慮に入れねばなら ないからである。たとえ、完全に統合された企業ですべての生産が行われたとしても、限界使用費用をゼロとみなすこと、つまり限界産出物の生産による設備の 限界マイナス投資を無視できると考えることは間違っている。

  The concepts of user cost and of supplementary cost also enable us to establish a clearer relationship between long-period supply price and short-period supply price. Long-period cost must obviously include an amount to cover the basic supplementary cost as well as the expected prime-cost appropriately averaged over the life of the equipment. That is to say, the long-period cost of the output is equal to the expected sum of the prime-cost and the supplementary cost; and, furthermore, in order to yield a normal profit, the long-period supply price must exceed the long-period cost thus calculated by an amount determined by the current rate of interest on loans of comparable term and risk, reckoned as a percentage of the cost of the equipment. Or if we prefer to take a standard “pure”rate of interest, we must include in the long-period cost a third term which we might call the risk-cost to cover the unknown possibilities of the actual yield differing from the expected yield.

  使用費用と補足費用の概念によって、我々はまた長期供給価格と短期供給価格の関係を以前より明確にすることができる。長期費用には明らかに予想主要費用 (設備の寿命を通じて適宜平均化されている)と基本的な補足費用とをまかなう額が含まれねばならない。つまり、産出物の長期費用は、主要費用と補足費用の 合計の予想値に等しいのである。さらには、正常利潤を生み出すためには、長期供給価格は、このように計算された長期費用を上回らなければならない。こうし て得られる正常利潤は、同種のリスクと満期(=既出)を持つ現行の公債の利子率(=リスク費用+利子費用)次第で決まってくる。この利子率は設備の価格に 一定率をかけて計算されたものである。また、もし我々が標準的な「純粋利子率」(=リスク費用を含む粗利子の対義語)を好むなら、長期費用にリスク費用を 第三項目として含めて、実際の収益が予想収益と異なるかもしれない事態に対処しなければならない。

Thus the long-period supply price is equal to the sum of the prime-cost, the supplementary cost, the risk cost and the interest cost, into which several components it can be analysed. The short-period supply price, on the other hand, is equal to the marginal prime-cost. The entrepreneur must, therefore, expect, when he buys or constructs his equipment, to cover his supplementary cost, his risk cost and his interest cost out of the excess of the marginal value of the prime-cost over its average value; so that in long-period equilibrium the excess of the marginal prime-cost over the average prime-cost is equal to the sum of the supplementary, risk and interest costs.[7]

つまり長期供給価格は主要費用と補足費用とリスク費用と利子費用の合計に等しい。長期供給価格はこれら複数の構成要素に分解できるのである。その一方で、 短期供給価格は限界主要費用(=限界要素費用+限界使用費用)に等しい。したがって、企業家は自分の設備を購入したり作ったりするときに、限界主要費用が 平均主要費用を上回る分によって補足費用とリスク費用と利子費用の合計がまかなえることを予想しなければならない。その結果、長期均衡状態においては、限 界主要費用が平均主要費用を上回る額が、補足費用とリスク費用と利子費用の合計に等しくなるのである[7]。

  The level of output, at which marginal prime-cost is exactly equal to the sum of the average prime and supplementary costs, has a special importance, because it is the point at which the entrepreneur's trading account breaks even. It corresponds, that is to say, to the point of zero net profit; whilst with a smaller output than this he is trading at a net loss. The extent to which the supplementary cost has to be provided for apart from the prime-cost varies very much from one type of equipment to another. Two extreme cases are the following:

  限界主要費用が平均主要費用と補足費用の合計とちょうど等しくなる産出量のレベルは特に重要である。なぜなら、そこで企業家の売買勘定の均衡がとれるから である。つまり、このレベルが純利潤がゼロになる点であり、これより少ない産出量では純損失になる。主要費用は別として、補足費用をどの程度準備すべきか は設備のタイプによって大きく異なる。次にその極端に違う二つのケースをあげる。

  (i) Some part of the maintenance of the equipment must necessarily take place pari passu(par passus「等しい歩み」の奪格) with the act of using it (e.g. oiling the machine). The expense of this (apart from outside purchases) is included in the factor cost. If, for physical reasons, the exact amount of the whole of the current depreciation has necessarily to be made good in this way, the amount of the user cost (apart from outside purchases) would be equal and opposite to that of the supplementary cost; and in long-period equilibrium the marginal factor cost would exceed the average factor cost by an amount equal to the risk and interest cost.

  (i)設備の維持が必ず設備の使用と同時に行われなければならない(例えば機械に注油する)タイプ。この費用は(外部からの購入を別として)要素費用に含 まれる。物質的な理由から当期の減価の正確な額が必ず要素費用から補填される場合には、使用費用の額(外部からの購入を別に)は補足費用の額と等しくなっ て、両者は相殺されてゼロになる。すると長期均衡状態においては、限界要素費用が平均要素費用を上回る額が、リスク費用と利子費用の合計と等しくなる(= 使用費用も補足費用もなし)。

  (ii) Some part of the deterioration in the value of the equipment only occurs if it is used. The cost of this is charged in user cost, in so far as it is not made good pari passu with the act of using it. If loss in the value of the equipment could only occur in this way, supplementary cost would be zero.

  (ii)設備の価値の減少が、設備が使用された場合にのみ起こるタイプ。この費用は設備の使用と同時に補填されない場合には、使用費用に計上される。設備の価値の損失がこのようにしてのみ起こる場合には、補足費用はゼロとなる(=補足費用だけなし)。

  It may be worth pointing out that an entrepreneur does not use his oldest and worst equipment first, merely because its user cost is low; since its low user cost may be outweighed by its relative inefficiency, i.e. by its high factor cost. Thus an entrepreneur uses by preference that part of his equipment for which the user cost plus factor cost is least per unit of output.[8] It follows that for any given volume of output of the product in question there is a corresponding user cost,[9] but that this total user cost does not bear a uniform relation to the marginal user cost, i.e. to the increment of user cost due to an increment in the rate of output.

  ここで指摘しておくのがいいと思われる事は、企業家は単に使用費用が低いという理由で自分の設備の一番古い物や質の悪い物を最初に使うことはないというこ とである。というのは、使用費用が低くても相対的に効率が悪くて要素費用が高くなっては意味がないからである。だから、企業家が好んで最初に使うのは自分 の設備のうちで、産出量1単位あたりの使用費用+要素費用が最小のものである[8]。したがって、製品のどの産出量に対しても、それに相応しい使用費用と いうものがある[9]。しかし、これを合計した使用費用は限界使用費用(産出量の増分に基づく使用費用の増分)と一定不変の関係にはないのである。

II

  User cost constitutes one of the links between the present and the future. For in deciding his scale of production an entrepreneur has to exercise a choice between using up his equipment now and preserving it to be used later on. It is the expected sacrifice of future benefit involved in present use which determines the amount of the user cost, and it is the marginal amount of this sacrifice which, together with the marginal factor cost and the expectation of the marginal proceeds, determines his scale of production. How, then, is the user cost of an act of production calculated by the entrepreneur?

第2節

  使用費用は現在と未来を結ぶ絆の一つである。というのは、生産規模を決めるときに企業家は自分の設備を使い切るか、それとも後でまた使うためにとっておく かの選択を迫られる。使用費用の額を決めるのは現在の使用によって失われると予想される将来の利益なのである。この失われる利益の限界値(=限界使用費 用)が限界要素費用と予想される限界売上といっしょになって企業家の生産規模を決める。では、一つの生産行為の使用費用を企業家はどうやって計算するの か。

  We have defined the user cost as the reduction in the value of the equipment due to using it as compared with not using it, after allowing for the cost of the maintenance and improvements which it would be worth while to undertake and for purchases from other entrepreneurs. It must be arrived at, therefore, by calculating the discounted value(=現在価値、次のpresent valueと同義) of the additional prospective yield which would be obtained at some later date if it were not used now. Now this must be at least equal to the present value of the opportunity to postpone replacement which will result from laying up the equipment; and it may be more.[10]

  我々の定義では、使用費用とは、設備の適切な維持改善費用と他の企業家からの購入費に、設備を使わない場合に比べて設備を使った場合に減少する設備の価値 (=減価償却費)を加えたものである。したがって、使用費用は、設備を今使わなければ将来余計に得られると予想される収益の割引価値(=現在価値)を計算 することで求められねばならない。だから、設備を使わないでおけば設備の交換を延期できるが、そのことで得られる利益の現在価値が、最低限の使用費用とな る。だから、それ以上である可能性がある[10]。

  If there is no surplus or redundant stock, so that more units of similar equipment are being newly produced every year either as an addition or in replacement, it is evident that marginal user cost will be calculable by reference to the amount by which the life or efficiency of the equipment will be shortened if it is used, and the current replacement cost. If, however, there is redundant equipment, then the user cost will also depend on the rate of interest and the current (i.e. re-estimated) supplementary cost over the period of time before the redundancy is expected to be absorbed through wastage, etc. In this way interest cost and current supplementary cost enter indirectly into the calculation of user cost.

  もし余った在庫がなく、毎年同種の設備をあらたに増設したり交換したりしている場合には、設備を交換するのに現在必要な費用と、使用することで設備の寿命 や効率が低下する額を足せば限界使用費用が計算出来るのは明らかである。しかし、設備が余っている場合には、使用費用は、設備の余剰分が損耗などによって 吸収されるのが予想されるまでの期間の利子率と当期補足費用(再評価された)(=既出)にも影響される。このようにして利子費用と当期補足費用は間接的に 使用費用の中に含まれるのである。

  The calculation is exhibited in its simplest and most intelligible form when the factor cost is zero. e.g. in the case of a redundant stock of a raw material such as copper, on the lines which I have worked out in my Treatise on Money, vol. ii. chap. 29. Let us take the prospective values of copper at various future dates, a series which will be governed by the rate at which redundancy is being absorbed and gradually approaches the estimated normal cost. The present value or user cost of a ton of surplus copper will then be equal to the greatest of the values obtainable by subtracting from the estimated future value at any given date of a ton of copper the interest cost and the current supplementary cost on a ton of copper between that date and the present.

  この計算が最も簡単で分かりやすいのは要素費用がゼロの場合である。それは例えば、銅などの原材料の在庫が余っている場合であり、私が『貨幣論』の第2巻 29章で扱ったやり方である。将来のさまざまな時点での銅の予想価格を考えてみると、その一連の価格を決めるのは銅の余剰分が吸収されて次第に推定される 標準価格に近づいていく早さである。つまり、余った1トンの銅の現在価値つまり使用費用は、1トンの銅の将来のある日の推定価格から、その日と現在の間に 生じる利子費用と当期補足費用を差し引いて得られる最大値と等しくなるだろう。

  In the same way the user cost of a ship or factory or machine, when these equipments are in redundant supply, is its estimated replacement cost discounted at the percentage rate of its interest and current supplementary costs to the prospective date of absorption of the redundancy.

  同様にして、船や工場や機械が供給過剰になったときの使用費用は、その設備の推定交換費用から、余剰が吸収される将来の日までの当期補足費用と利子率を引いた割引価値(=現在価値)である。

  We have assumed above that the equipment will be replaced in due course by an identical article. If the equipment in question will not be renewed identically when it is worn out, then its user cost has to be calculated by taking a proportion of the user cost of the new equipment, which will be erected to do its work when it is discarded, given by its comparative efficiency.

  上記においては設備は将来同種のものに交換されると想定されていた。しかし、問題の設備が消耗したときに同じものに交換できない場合、その設備の使用費用 は、古い設備が廃棄される時に代わりに設置される新しい設備の使用費用を設備の相対的な効率の度合いで換算して計算されなければならない。

III

  The reader should notice that, where the equipment is not obsolescent but merely redundant for the time being, the difference between the actual user cost and its normal value (i.e. the value when there is no redundant equipment) varies with the interval of time which is expected to elapse before the redundancy is absorbed. Thus if the type of equipment in question is of all ages and not “bunched' so that a fair proportion is reaching the end of its life annually, the marginal user cost will not decline greatly unless the redundancy is exceptionally excessive. In the case of a general slump, marginal user cost will depend on how long entrepreneurs expect the slump to last. Thus the rise in the supply price when affairs begin to mend may be partly due to a sharp increase in marginal user cost due to a revision of their expectations.

第3節

  読者が注意しなければならないのは、設備が旧式になったのではなく単に当面余っているだけの場合には、今の使用費用と設備の標準価格(つまり余剰設備がな くなったときの値)の差は、その余剰が吸収されるまでにかかると予想される期間によって異なるということである。だから、問題となる設備のタイプが全部同 じ種類ではなく様々な寿命のものからなっていて、毎年かなりの割合が寿命を終える場合には、余剰が例外的に過度でない限り、限界使用費用が大きく低下する ことはない。全般的な不況の場合には、限界使用費用はその不況がどれくらい続くかについての企業家たちの予想に依存する。だから、景気が好転しはじめた時 の供給価格の上昇は、一部は企業家たちの予想の更新によって生じた限界使用費用の急激な増加によって起こるのである。

  It has sometimes been argued, contrary to the opinion of business men, that organised schemes for scrapping redundant plant cannot have the desired effect of raising prices unless they apply to the whole of the redundant plant. But the concept of user cost shows how the scrapping of (say) half the redundant plant may have the effect of raising prices immediately. For by bringing the date of the absorption of the redundancy nearer, this policy raises marginal user cost and consequently increases the current supply price. Thus business men would seem to have the notion of user cost implicitly in mind, though they do not formulate it distinctly.

  実業家たちの意見に反して、余剰施設の廃棄を組織的に計画しても、それが余剰施設全体に及ばない限り、価格を引き上げる望ましい効果は得られないと主張さ れてきた。しかし、使用費用の考え方からすれば、たとえ半分でも余剰施設を廃棄すれば直ちに価格を引き上げる効果があることになる。というのは、この方針 に従えば余剰分が吸収される日が早まるので、限界使用費用は増加してその結果当期の供給価格が上昇するからである。つまり、実業家たちは使用費用の考え方 をはっきり表明してはいないが、暗黙のうちに心に留めているのだ。

  If the supplementary cost is heavy, it follows that the marginal user cost will be low when there is surplus equipment. Moreover, where there is surplus equipment, the marginal factor and user costs are unlikely to be much in excess of their average value. If both these conditions are fulfilled, the existence of surplus equipment is likely to lead to the entrepreneur's working at a net loss, and perhaps at a heavy net loss. There will not be a sudden transition from this state of affairs to a normal profit, taking place at the moment when the redundancy is absorbed. As the redundancy becomes less, the user cost will gradually increase; and the excess of marginal over average factor and user cost may also gradually increase.

  もし補足費用が大きいと、余剰設備がある場合には限界使用費用は小さくなる。さらに、余剰設備がある場合、限界要素費用と限界使用費用はそれぞれの平均値 を大きく上回りそうにない。つまり、両方の条件が揃っている場合には、余剰設備の存在は企業家に純損失、しかも恐らくひどい純損失のもとでの操業を余儀な くさせると思われる。この状態から正常利潤に急速に移行することはできず、それは余剰が吸収された時にやっと実現される。余剰が減少するに従って、使用費 用は次第に上昇する。そして限界要素費用と限界使用費用も平均要素費用と平均使用費用をそれぞれ次第に上回るようになるのである。

IV

  In Marshall's Principles of Economics (6th ed. p. 360) a part of user cost is included in prime-cost under the heading of “extra(余分な、特別な、追加の、限界的な) wear-and-tear of plant”. But no guidance is given as to how this item is to be calculated or as to its importance. In his Theory of Unemployment (p. 42) Professor Pigou expressly assumes that the marginal disinvestment in equipment due to the marginal output can, in general, be neglected: “The differences in the quantity of wear-and-tear suffered by equipment and in the costs of non-manual labour employed, that are associated with differences in output, are ignored, as being, in general, of secondary importance”.[11] Indeed, the notion that the disinvestment in equipment is zero at the margin of production runs through a good deal of recent economic theory. But the whole problem is brought to an obvious head as soon as it is thought necessary to explain exactly what is meant by the supply price of an individual firm.

第4節

  マーシャルの『経済学原理』(第6版360頁)では、使用費用の一部が「施設の追加的消耗」という項目のなかに含まれている。しかし、この項目の計算方法 も重要性の説明も何もない。ピグー教授は『失業理論』(42頁)のなかで、限界産出量による設備の限界マイナス投資(=既出)は普通は無視してよいとはっ きり言っている。「産出量の変化に伴う設備の消耗量と非肉体労働の雇用費用の変化はふつう二次的な重要性しかないので無視できる」と[11]。確かに、設 備のマイナス投資は生産の限界状況ではゼロになるという考え方は最近の多くの経済理論に広まっている。しかし、個々の企業の供給価格が意味するものを正確 に説明する必要性に思い及ぶやいなや、問題の全体像は明らかになるのである。

  It is true that the cost of maintenance of idle plant may often, for the reasons given above, reduce the magnitude of marginal user cost, especially in a slump which is expected to last a long time. Nevertheless a very low user cost at the margin is not a characteristic of the short period as such, but of particular situations and types of equipment where the cost of maintaining idle plant happens to be heavy, and of those disequilibria(不均衡) which are characterised by very rapid obsolescence or great redundancy, especially if it is coupled with a large proportion of comparatively new plant.

  遊休施設の維持費は上記の理由によって限界使用費用の額を減少させる。不況の長期化が予想される場合はとくにそうである。しかし、限界使用費用が非常に低 くなることは短期の特徴ではない。それは、設備の状況や設備のタイプが特殊なために遊休施設の維持費が大きくなる場合の特徴であり、また世の中が不安定に なって設備の旧式化が早まったり余剰が増大した場合の特徴である。特に、比較的新しい施設の割合が大きい時にそうなりがちである。

  In the case of raw materials the necessity of allowing for user cost is obvious;― if a ton of copper is used up to-day it cannot be used to-morrow, and the value which the copper would have for the purposes of to-morrow must clearly be reckoned as a part of the marginal cost. But the fact has been overlooked that copper is only an extreme case of what occurs whenever capital equipment is used to produce. The assumption that there is a sharp division between raw materials where we must allow for the disinvestment due to using them and fixed capital where we can safely neglect it, does not correspond to the facts; ― especially in normal conditions where equipment is falling due for replacement every year and the use of equipment brings nearer the date at which replacement is necessary.

  原材料の場合に使用費用を考慮しなければならないのは明らかである。もし1トンの銅を今日使い切ったら明日には使えない。だから、明日のために銅がもって いる価値は明らかに限界費用の一部として計算されねばならない。しかし、銅の例は資本設備が生産に使われる時に何が起こるかを示す極端な一例でしかない、 という事実は見過ごされてきた。使用すればマイナス投資が生ずることを考慮しなければならない原材料と、それを無視できる固定資本(=建物や機械など)の 間には明確な違いがあるとする考え方は事実に反している。設備が毎年交換時期に至ったり、設備を使用すれば交換が必要な日が近づいてくるという普通の状況 では特にそうである。

  It is an advantage of the concepts of user cost and supplementary cost that they are as applicable to working and liquid capital as to fixed capital. The essential difference between raw materials and fixed capital lies not in their liability to user and supplementary costs, but in the fact that the return to liquid capital consists of a single term; whereas in the case of fixed capital, which is durable and used up gradually, the return consists of a series of user costs and profits earned in successive periods.

  使用費用と補足費用の考え方の利点は、運転資本と流動資本だけでなく固定資本にも適用できることである。原材料と固定資本の間の重要な違いは使用費用と補 足費用が必要かどうかの違いではなく、流動資本の収益は一期であるのに対して、固定資本の場合には耐久性があって徐々に使い切るので、その利益を構成する 使用費用と利潤は何期にもわたることである。

Author's Footnotes

[7]. This way of putting it depends on the convenient assumption that the marginal prime-cost curve is continuous throughout its length for changes in output. In fact, this assumption is often unrealistic, and there may be one or more points of discontinuity, especially when we reach an output corresponding to the technical full capacity of the equipment. In this case the marginal analysis partially breaks down; and the price may exceed the marginal prime-cost, where the latter is reckoned in respect of a small decrease of output. (Similarly there may often be a discontinuity in the downward direction. i.e. for a reduction in output below a certain point). This is important when we are considering the short-period supply price in long-period equilibrium, since in that case any discontinuities, which may exist corresponding to a point of technical full capacity, must be supposed to be in operation. Thus the short-period supply price in long-period equilibrium may have to exceed the marginal prime-cost (reckoned in terms of a small decrease of output).

[8]. Since user cost partly depends on expectations as to the future level of wages, a reduction in the wage-unit which is expected to be short-lived will cause factor cost and user cost to move in different proportions and so affect what equipment is used, and, conceivably, the level of effective demand, since factor cost may enter into the determination of effective demand in a different way from user cost.

[9]. The user cost of the equipment which is first brought into use is not necessarily independent of the total volume of output (see below); i.e. the user cost may be affected all along the line when the total volume of output is changed.(ネットのテキストではnot necessarilyがnot onlyになっていることが多い)

[10]. It will be more when it is expected that a more than normal yield can be obtained at some later date, which, however, is not expected to last long enough to justify (or give time for) the production of new equipment. To-day's user cost is equal to the maximum of the discounted values of the potential expected yields of all the tomorrows.

[11]. Mr. Hawtrey (Economica, May 1934, p. 145) has called attention to Prof. Pigou's identification of supply price with marginal labour cost, and has contended that Prof. Pigou's argument is thereby seriously vitiated.

著者注

[7]  この構成の仕方は、限界主要費用の曲線は産出量の変化に応じて全体にわたって連続しているという便宜的な仮定に依存している。しかし、この仮定はあまり現 実的ではなく、とくに産出量が設備の技術力の頂点に達した場合には、不連続点が発生する可能性がある。この場合には、限界分析は部分的に働かなくなる。そ して価格は限界主要費用を上回る可能性がある。この場合には、限界主要費用は産出量の僅かな減少を考慮して計算されるからである。(同様にして曲線が下向 きの場合、つまり産出量がある点以下に減少する場合にも不連続点が発生する可能性がある)。これは長期均衡状態における短期供給価格を検討する場合に重要 である。なぜなら、この場合には技術力の頂点に発生するような不連続点がいつでも起きると考えなければならないからである。だから、長期均衡状態における 短期供給価格は限界主要費用(産出量の僅かの減少に応じて計算された)を上回ると考えなければならない。

[8]  使用費用は将来の賃金レベルについての予想に一部を依存するため、一時的だと思われる単位賃金の引き下げによって、要素費用(=賃金)と使用費用は異なっ た割合で変動して、そのために企業家による設備の選び方が違ってくるし、有効需要のレベルも違ってくる。なぜなら、要素費用は使用費用とは違うやり方で有 効需要の決定に関与してくるからである。

[9]  最初に使用される設備の使用費用は総産出量と必ずしも無関係であるわけではない(以下を見よ)、この使用費用は総産出量が変化するにつれて変わってくる可能性がある。

[10]  使用費用がそれ以上になるのは、通常収益以上の収益が後に得られると予想できるが、その収益は新たな設備を自分で作れるほど長くは続くないと思われる場合 である。今日の使用費用は明日以降の潜在的な予想収益の割引価値(=現在価値)の最大値と等しいのである。

[11]  ホートレー氏(『エコノミカ』1934年5月145頁)はピグー教授が供給価格と限界労働費用を同一視していることに注目して、ピグー教授の議論はそれによって著しく価値を損なっていると主張している。


Chapter 7. The Meaning of Saving and Investment Further Considered

第7章 貯蓄と投資の意味の再考

I

  IN the previous chapter Saving and Investment have been so defined that they are necessarily equal in amount, being, for the community as a whole, merely different aspects of the same thing. Several contemporary writers (including myself in my Treatise on Money) have, however, given special definitions of these terms on which they are not necessarily equal. Others have written on the assumption that they may be unequal without prefacing their discussion with any definitions at all. It will be useful, therefore, with a view to relating the foregoing to other discussions of these terms, to classify some of the various uses of them which appear to be current.

第1節

  前の章で「貯蓄」と「投資」は必ず同額であり、社会全体にとっては両者は同じ物の異なる二つの面でしかないと定義された。しかし、多くの現代の学者(『貨 幣論』を書いた私を含めて)はこれらの用語に特殊な定義をほどこして両者は必ずしも等しくないと言っている。また、他の学者は全く定義もせず前置きもなく 両者は一致しないことがあることを前提にしている。だから、これらの用語についてのこれまでの議論をそのほかの議論と結びつけるために、現在見ることの出 来るこの用語の様々な用法を分類してみるのは有益だろう。

  So far as I know, everyone agrees in meaning by Saving the excess of income over what is spent on consumption. It would certainly be very inconvenient and misleading not to mean this. Nor is there any important difference of opinion as to what is meant by expenditure on consumption. Thus the differences of usage arise either out of the definition of Investment or out of that of Income.

  私の知る限り、「貯蓄」が所得から消費支出を引いた余りであることを意味する点は誰もが一致している。もしそうでなければ非常に不便だろうし紛らわしいこ とになるのは必定である。「消費支出」の意味についても重大な意見の違いはない。したがって、用語の混乱の原因は「投資」の定義か「所得」の定義にあるこ とになる。

II

  Let us take Investment first. In popular usage it is common to mean by this the purchase of an asset, old or new, by an individual or a corporation. Occasionally, the term might be restricted to the purchase of an asset on the Stock Exchange. But we speak just as readily of investing, for example, in a house, or in a machine, or in a stock of finished or unfinished goods; and, broadly speaking, new investment, as distinguished from reinvestment, means the purchase of a capital asset of any kind out of income. If we reckon the sale of an investment as being negative investment, i.e. disinvestment, my own definition is in accordance with popular usage; since exchanges of old investments necessarily cancel out.

第2節

  「投資」から始めよう。一般的な用法では投資とは個人や企業による新旧の資産の購入を意味するのが普通である。時には、この用語は証券市場での資産の購入 に限定されることがあるかもしれない。しかし、我々は例えば家や機械あるいは完成品や未完成品の在庫に対しても同じ様に投資すると言う。そして、広い意味 で「新投資」とは「再投資」と区別して、所得によって何らかの資本資産を購入することを意味する。もし投資の売却を負の投資、すなわちマイナス投資とみな すなら、私自身の定義は一般的な用法と合致している。なぜなら古い投資の売りと買いは必ず釣り合っているからである。

We have, indeed, to adjust for the creation and discharge of debts (including changes in the quantity of credit or money); but since for the community as a whole the increase or decrease of the aggregate creditor position is always exactly equal to the increase or decrease of the aggregate debtor position, this complication also cancels out when we are dealing with aggregate investment. Thus, assuming that income in the popular sense corresponds to my net income, aggregate investment in the popular sense coincides with my definition of net investment, namely the net addition to all kinds of capital equipment, after allowing for those changes in the value of the old capital equipment which are taken into account in reckoning net income.

もちろん、債務の創設と解消(信用や貨幣の量の変更を含む)を勘案すべきではある。しかし、社会全体として債権者の立場にいる人の総数の増減はつねに債務 者の立場にいる人の増減とぴったり一致するので、我々が「総投資」を扱うときには、この複雑な現象(=債務の創設と解消)は釣り合っているのである。だか ら、一般的な意味の所得が私の言う「純所得」と一致すると考えるなら、一般的な意味での「総投資」は私の定義する「純投資」と一致する。即ち、総投資と は、古い資本設備の価値のうちで純所得の計算に含まれる価格の変化(=使用費用と補足費用)を考慮した、あらゆる種類の資本設備に対する純追加(=既出) なのである。

  Investment, thus defined, includes, therefore, the increment of capital equipment, whether it consists of fixed capital, working capital or liquid capital; and the significant differences of definition (apart from the distinction between investment and net investment) are due to the exclusion from investment of one or more of these categories.

  したがって、このように定義された投資は資本設備の増加であり、それが固定資本、運転資本、流動資本であるかに関わらない。そして様々な定義の違いは主に(投資と純投資の違いを別にして)投資からこれらの種類の資本のいくつかを除外することから来ている。

  Mr. Hawtrey, for example, who attaches great importance to changes in liquid capital, i.e. to undesigned increments (or decrements) in the stock of unsold goods, has suggested a possible definition of investment from which such changes are excluded. In this case an excess of saving over investment would be the same thing as an undesigned increment in the stock of unsold goods, i.e. as an increase of liquid capital. Mr. Hawtrey has not convinced me that this is the factor to stress; for it lays all the emphasis on the correction of changes which were in the first instance unforeseen, as compared with those which are, rightly or wrongly, anticipated.

  例えば、ホートレー氏は流動資本の変化に、即ち売れ残り品の在庫の予期せぬ増減に重きを置いたので、流動資本の変化を除外した投資の定義を提案している。 この場合には、貯蓄が投資を上回る分が、売れ残り品の在庫の予期せぬ増加、つまり流動資本の増加と同じものとなる。これが強調すべき要素であるというホー トレー氏の意見は私には説得力がなかった。というのは、彼の説は、良かれ悪しかれ予想される変化よりは、むしろ最初に予想されなかった変化の修正に全ての 力点を置いているからである。

Mr. Hawtrey regards the daily decisions of entrepreneurs concerning their scale of output as being varied from the scale of the previous day by reference to the changes in their stock of unsold goods. Certainly, in the case of consumption goods, this plays an important part in their decisions. But I see no object in excluding the play of other factors on their decisions; and I prefer, therefore, to emphasise the total change of effective demand and not merely that part of the change in effective demand which reflects the increase or decrease of unsold stocks in the previous period. Moreover, in the case of fixed capital, the increase or decrease of unused capacity corresponds to the increase or decrease in unsold stocks in its effect on decisions to produce; and I do not see how Mr. Hawtrey's method can handle this at least equally important factor.

ホートレー氏は、企業家が日々決定する産出量は、売れ残り品の在庫の変化に応じて前日の産出量から変化すると考える。確かに消費財の場合、これは企業家の 決定に重要な役割を果たす。しかし、企業家の決定に及ぼす他の要素の役割を除外するのは無意味だと思う。だから、私はむしろ有効需要の全体的な変化を強調 すべきであって、有効需要の変化のうちで前期の売れ残り品の在庫の増減を反映する部分だけを強調すべきだとは思わない。さらに、固定資本(=機械など)の 場合、使われていない能力の増減は、生産決定に対する影響力の点では、売れ残り品の在庫の増減に匹敵する。そして、少なくとも同程度に重要なこの要素を ホートレー氏の方法がどう扱うか私には分からないのである。

  It seems probable that capital formation and capital consumption, as used by the Austrian school of economists, are not identical either with investment and disinvestment as defined above or with net investment and disinvestment. In particular, capital consumption is said to occur in circumstances where there is quite clearly no net decrease in capital equipment as defined above. I have, however, been unable to discover a reference to any passage where the meaning of these terms is clearly explained. The statement, for example, that capital formation occurs when there is a lengthening of the period of production does not much advance matters.

  オーストリア学派の経済学者によって使われている資本形成と資本消費という用語はおそらく上で定義した投資とマイナス投資とも純投資とマイナス純投資とも 一致しないと思われる。特に、資本消費は上で定義した資本設備の純減価(=使用費用と補足費用を含まない)が全くないことが明らかな状況で起きると言われ ている。しかし、私はこれらの用語の意味が明快に説明されているところを見たことがない。例えば、資本形成は生産期間が長期化するときに起こると言ったと ころで、事態はたいして何も変わらないのだ。

III

  We come next to the divergences between saving and investment which are due to a special definition of income and hence of the excess of income over consumption. My own use of terms in my Treatise on Money is an example of this. For, as I have explained in Chapter 6 above, the definition of income, which I there employed, differed from my present definition by reckoning as the income of entrepreneurs not their actually realised profits but (in some sense) their “normal profit”. Thus by an excess of saving over investment I meant that the scale of output was such that entrepreneurs were earning a less than normal profit from their ownership of the capital equipment; and by an increased excess of saving over investment I meant that a decline was taking place in the actual profits, so that they would be under a motive to contract output.

第3節

  次に、所得の特殊な定義および所得が消費を上回る分の特殊な定義に起因する貯蓄と投資の不一致に移ろう。私の『貨幣論』での用語の使い方はこの一例であ る。というのは、前の第6章で説明したように、あの本の中で使っている所得の定義は私の今の定義とは違って、実際に実現された利潤ではなく(ある意味で) 企業家の「正常利潤」を企業家の所得とみなしているからである(=既出)。そして、そこで私は、貯蓄が投資を上回るということは、産出量が少なくて自分の 資本設備から企業家が得られる利潤が正常利潤以下であることを意味し、また貯蓄が投資を上回る分が増えるということは、実利潤が低下して、企業家は産出量 を縮小しようとしていることを意味していた。

As I now think, the volume of employment (and consequently of output and real income) is fixed by the entrepreneur under the motive of seeking to maximise its present and prospective profits (the allowance for user cost being determined by his view as to the use of equipment which will maximise his return from it over its whole life); whilst the volume of employment which will maximise his profit depends on the aggregate demand function given by his expectations of the sum of the proceeds resulting from consumption and investment respectively on various hypotheses. In my Treatise on Money the concept of changes in the excess of investment over saving, as there defined, was a way of handling changes in profit, though I did not in that book distinguish clearly between expected and realised results.[1] I there argued that change in the excess of investment over saving was the motive force governing changes in the volume of output.

今考えるに、企業家は現在と将来の利潤を最大化しようとする動機のもとで雇用量(それは結果的には産出量と実質賃金の量になる)を決めるものである(=第 3章2節に既出)(使用費用の計算は設備の寿命が終わるまでに得られる収益を最大化するような設備の利用法についての企業家の考え方によって決まる)。一 方、企業家の利潤を最大化する雇用量は総需要関数によって与えられる。この総需要関数は様々な仮定のもと消費と投資の両方から生まれる売上合計に対する企 業家の予想値によって与えられる。『貨幣論』のなかで、私は予想された結果と実現された結果を明確に区別していなかったが[1]、投資があの本で定義され た貯蓄を上回る分(=上記と逆)の「変化」を考えることは、利潤の変化を扱う方法だった。私があの本で主張したことは、投資が貯蓄を上回る分の変化は、産 出量の変化を左右する要因だということなのである。

Thus the new argument, though (as I now think) much more accurate and instructive, is essentially a development of the old. Expressed in the language of my Treatise on Money, it would run: the expectation of an increased excess of Investment over Saving, given the former volume of employment and output, will induce entrepreneurs to increase the volume of employment and output. The significance of both my present and my former arguments lies in their attempt to show that the volume of employment is determined by the estimates of effective demand made by the entrepreneurs, an expected increase of investment relatively to saving as defined in my Treatise on Money being a criterion of an increase in effective demand. But the exposition in my Treatise on Money is, of course, very confusing and incomplete in the light of the further developments here set forth.

だから、今回の新たな議論は、以前の議論よりもはるかに正確で役に立つものだと思っているが、基本的には以前の議論の発展である。『貨幣論』の中の言葉遣 いを使えば「以前の雇用量と産出量のもと、投資が貯蓄を上回る分が増加すると予想できるなら、企業家は雇用量と産出量を増やそうとするだろう」となる。私 の現在の議論と以前の議論の意義は両方とも、『貨幣論』で定義された貯蓄に対する投資の相対的な増加の予想値が有効需要の増加の尺度であり、雇用量を決め るのは有効需要に対する企業家の推測であることを示す点にある。しかし、『貨幣論』のなかの表現は、本書で提示された議論の進展からも見れが、当然なが ら、非常に紛らわしく不完全なものである。

  Mr. D. H. Robertson has defined to-day's income as being equal to yesterday's consumption plus investment, so that to-day's saving, in his sense, is equal to yesterday's investment plus the excess of yesterday's consumption over to-day's consumption. On this definition saving can exceed investment, namely, by the excess of yesterday's income (in my sense) over to-day's income. Thus when Mr. Robertson says that there is an excess of saving over investment, he means literally the same thing as I mean when I say that income is falling, and the excess of saving in his sense is exactly equal to the decline of income in my sense. If it were true that current expectations were always determined by yesterday's realised results, to-day's effective demand would be equal to yesterday's income. Thus Mr. Robertson's method might be regarded as an alternative attempt to mine (being, perhaps, a first approximation to it) to make the same distinction, so vital for causal analysis, that I have tried to make by the contrast between effective demand and income.[2]

  D.H.ロバートソン氏は、今日の所得は「昨日の消費+投資」と等しいと定義している。だから、彼の言う意味では今日の貯蓄は「昨日の投資+昨日の消費- 今日の消費」に等しくなる。即ち、この定義では貯蓄が投資を上回るのは「昨日の所得」(私の意味での)が「今日の所得」を上回る分だけということになる。 つまり、貯蓄が投資を上回るとロバートソン氏が言う時、それは私が「所得が低下する」と言うのとまったく同じ事を意味しており、彼の言う「貯蓄の超過」 は、私の言う「所得の低下」とちょうど同じことを意味している。もし仮に、現在の予想が昨日実現された結果によって常に決まるというのが真実なら、今日の 有効需要は昨日の所得と等しいことになる。つまり、ロバートソン氏の方法は私の方法と代替可能な試み(多分最も私の方法に近いもの)と見做すことが出来る かもしれない。彼の方法はまさに原因分析にとって決め手となる区別(=予想された結果と実現された結果の区別)、私が有効需要と所得の対比によって行おう とした区別と同じ区別をしているからである。[2]

IV

  We come next to the much vaguer ideas associated with the phrase “forced saving”. Is any clear significance discoverable in these? In my Treatise on Money (vol. i. p. 171, footnote) I gave some references to earlier uses of this phrase and suggested that they bore some affinity to the difference between investment and “saving” in the sense in which I there used the latter term. I am no longer confident that there was in fact so much affinity as I then supposed. In any case, I feel sure that “forced saving” and analogous phrases employed more recently (e.g. by Professor Hayek or Professor Robbins) have no definite relation to the difference between investment and “saving” in the sense intended in my Treatise on Money. For whilst these authors have not explained exactly what they mean by this term, it is clear that “forced saving”, in their sense, is a phenomenon which results directly from, and is measured by, changes in the quantity of money or bank-credit.

第4節

  次に「強制貯蓄」(=インフレ下で消費を控えるため貯蓄が増えるように見えること)という言葉と結びついたかなり曖昧な考え方を扱おう。この考え方のなか に何か重要なものが見い出せるだろうか。『貨幣論』(第1巻171頁脚注)で私はこの言葉のもっと古い使用例に言及して、それが投資と「貯蓄」(あの本の 意味による)との差額に似ていると言った。今では当時思ったほど実際にそれほどの類似性があるか自信はない。いづれにせよ、確かなのは「強制貯蓄」やそれ と似た最近使われる言葉(例えばハイエク教授やロビンス教授のもの)は私が『貨幣論』の中で意図した意味での「貯蓄」と投資との差額とは何ら明確なつなが りがないということである。というのは、これらの学者たちはこの言葉で何を意味するかを正確に説明していないが、彼らのいう意味での「強制貯蓄」とは貨幣 量や銀行信用(=貸出金)の量の変化から直接的に生まれ、その変化によって測られる現象であることは明らかだからである。

  It is evident that a change in the volume of output and employment will, indeed, cause a change in income measured in wage-units(単位賃金数); that a change in the wage-unit will cause both a redistribution of income between borrowers and lenders and a change in aggregate income measured in money; and that in either event there will (or may) be a change in the amount saved. Since, therefore, changes in the quantity of money may result, through their effect on the rate of interest, in a change in the volume and distribution of income (as we shall show later), such changes may involve, indirectly, a change in the amount saved.

  確かに、(=貨幣量の変化に起因する)産出量と雇用量の変化は単位賃金数で測った所得の変化をもたらし、単位賃金の変化は貸手と借手の間に所得の再分配を もたらすだけでなく、名目総所得も変化させ、さらに、どちらの場合にも貯蓄高に変化(=強制貯蓄)をもたらす(あるいはその可能性がある)のは明らかであ る。したがって、貨幣量の変化は利子率への影響を通じて所得の量と分配に変化(後に見るような)をもたらす可能性があるから、貨幣量の変化が間接的に貯蓄 量の変化(=強制貯蓄)をもたらす可能性はある。

But such changes in the amounts saved are no more “forced savings” than any other changes in the amounts saved due to a change in circumstances; and there is no means of distinguishing between one case and another, unless we specify the amount saved in certain given conditions as our norm or standard. Moreover, as we shall see, the amount of the change in aggregate saving which results from a given change in the quantity of money is highly variable and depends on many other factors.

しかしながら、貯蓄量のこのような変化は決して「強制貯蓄」ではない。それは環境の変化によって貯蓄量に変化があった場合、それが強制貯蓄でないのと同じ である。つまり特定の条件のもとでの貯蓄量を我々の判断基準あるいは標準として指定しない限り、強制貯蓄かどうかを区別する方法はない。さらに、後に見る ように、貨幣量の変化から来る総貯蓄量の変化は非常に多様で、他の多くの原因に左右される。

  Thus “forced saving” has no meaning until we have specified some standard rate of saving. If we select (as might be reasonable) the rate of saving which corresponds to an established state of full employment, the above definition would become: “Forced saving is the excess of actual saving over what would be saved if there were full employment in a position of long-period equilibrium”. This definition would make good sense, but a sense in which a forced excess of saving would be a very rare and a very unstable phenomenon, and a forced deficiency of saving the usual state of affairs.

  つまり「強制貯蓄」は標準貯蓄率を指定しない限り意味が無いのである。もし確立した完全雇用状態に対応する貯蓄率を(そうすれば理にかなっているかもしれ ない)標準貯蓄率に選ぶなら、上記の定義は次のようになる。「強制貯蓄とは長期均衡状態で完全雇用のときに行われる貯蓄を現実の貯蓄が上回る額である」。 この定義だとちゃんとした意味になるが、この場合、強制的な貯蓄超過は非常に珍しい不安定な現象で、強制的な貯蓄不足が普通の状態になるだろう。

  Professor Hayek's interesting “Note on the Development of the Doctrine of Forced Saving”[3] shows that this was in fact the original meaning of the term. “Forced saving” or “forced frugality” was, in the first instance, a conception of Bentham's; and Bentham expressly stated that he had in mind the consequences of an increase in the quantity of money (relatively to the quantity of things vendible for money) in circumstances of “all hands being employed and employed in the most advantageous manner”[4]. In such circumstances, Bentham points out, real income cannot be increased, and, consequently, additional investment, taking place as a result of the transition, involves forced frugality “at the expense of national comfort and national justice”.

  ハイエク教授の興味深い論文『強制貯蓄理論の発展についての覚書』[3]を見れば、これがこの言葉の元々の意味だったことがわかる。最初は「強制貯蓄」あ るいは「強制倹約」はベンサムの考えだった。そしてベンサムは「全員が雇われており、しかも最も有利なように雇われている」状況で(貨幣によって購買可能 な品物の量に比べて)貨幣量が増加した結果について考えているとはっきり述べている[4]。そのような状況では実質所得が増加することは不可能なので、そ の過渡期に起こる投資の増加は「国民の安寧と正義を犠牲にした」強制倹約を引き起こすとベンサムは指摘しているのだ。

All the nineteenth-century writers who dealt with this matter had virtually the same idea in mind. But an attempt to extend this perfectly clear notion to conditions of less than full employment involves difficulties. It is true, of course (owing to the fact of diminishing returns to an increase in the employment applied to a given capital equipment), that any increase in employment involves some sacrifice of real income to those who were already employed, but an attempt to relate this loss to the increase in investment which(先行詞はlossである) may accompany the increase in employment is not likely to be fruitful. At any rate I am not aware of any attempt having been made by the modern writers who are interested in “forced saving” to extend the idea to conditions where employment is increasing; and they seem, as a rule, to overlook the fact that the extension of the Benthamite concept of forced frugality to conditions of less than full employment requires some explanation or qualification.

この問題を扱う19世紀の学者たちは全員がほとんど同じ考え方をしていた。しかし、この完全に明白な考えを不完全雇用の状況にまで押し広げて適用しようと する試みは困難をともなう。もちろん(一定の資本設備に適用される雇用の増加に対して収益が次第に減少するという事実のために)雇用の「どんな」増加も既 存の被雇用者の実質賃金の低下を引き起こすのは事実であるが、雇用の増加に伴う実質賃金の低下を投資の増加に結びつけようとする試みは上手くいきそうにな い。とにかく、強制貯蓄に関心のある現代の学者たちがこの考えを雇用が増加する状況にまで押し広げようとしたどんな試みも私は知らない。ベンサムの強制倹 約の考えを不完全雇用の状況に押し広げるためには若干の説明か条件付けが必要なことに、概して彼らは気付いていないようなのである。

V

  The prevalence of the idea that saving and investment, taken in their straightforward sense, can differ from one another, is to be explained, I think, by an optical illusion due to regarding an individual depositor's relation to his bank as being a one-sided transaction, instead of seeing it as the two-sided transaction which it actually is. It is supposed that a depositor and his bank can somehow contrive between them to perform an operation by which savings can disappear into the banking system so that they are lost to investment, or, contrariwise, that the banking system can make it possible for investment to occur, to which no saving corresponds.

第5節

  貯蓄と投資を素直な意味にとってこの二つが互いに一致しない可能性があるとする考え方が広まっているが、その理由は、私が思うに、個人の預金者と銀行との 関係は実際には二つの面がある取り引きなのに、それを一つの意味しかない取り引きだとする思い込みによって説明できる。つまり、預金者と銀行が一緒になっ てどうにかして預金が銀行の中に消えてしまい投資に回らないように出来るとか、あるいは逆に、銀行は預金とは無関係に投資を発生させることが出来ると思わ れているのだ。

But no one can save without acquiring an asset, whether it be cash or a debt or capital-goods; and no one can acquire an asset which he did not previously possess, unless either an asset of equal value is newly produced or someone else parts with an asset of that value which he previously had. In the first alternative there is a corresponding new investment: in the second alternative someone else must be dissaving an equal sum.

しかし、人は誰しも何らかの貯蓄をする時には必ず何らかの資産(それが現金であれ債務であれ資本財であるかは問わない)を獲得している。そして、人がそれ まで持っていなかった資産を獲得するためには、同じ価値の資産が新たに生産されるか、あるいは誰か他の人がそれまで持っていた同じ価値の資産を手放さなけ ればならない。最初の場合は、それに対応する新投資が行われるのであり、二番目の場合は、誰か他の人が同じ額の貯蓄を引き出さねばならない。

For his loss of wealth must be due to his consumption exceeding his income, and not to a loss on capital account through a change in the value of a capital-asset, since it is not a case of his suffering a loss of value which his asset formerly had; he is duly receiving the current value of his asset and yet is not retaining this value in wealth of any form, i.e. he must be spending it on current consumption in excess of current income. Moreover, if it is the banking system which parts with an asset, someone must be parting with cash. It follows that the aggregate saving of the first individual and of others taken together must necessarily be equal to the amount of current new investment.

というのは、後者の富の喪失は所得を上回る消費の結果であり、資本資産の価値の変化による資産勘定のマイナスのせいではない。なぜなら、この場合、彼の資 産が以前に持っていた価値は損なわれていないからである。彼は(=預金を引き出して)まさに現在の資産の価値を受取ながら、しかもこの価値をどのような富 の形でももう所有していない。彼はその富を現在の所得を上回る消費に支出しているに違いないのである。さらに、もし銀行から資産が離れていったのなら、そ れは誰かが現金を手放しているに違いない。こうして、最初の人とそのほかの人達の貯蓄をひとまとめにした総貯蓄は現在の新たな投資量と必然的に等しくなら ざるを得ないのである。

  The notion that the creation of credit(信用創造、貨幣創造) by the banking system allows investment to take place to which “no genuine saving(真正貯蓄)” corresponds can only be the result of isolating one of the consequences of the increased bank-credit to the exclusion of the others. If the grant of a bank-credit to an entrepreneur additional to the credits already existing allows him to make an addition to current investment which(先行詞はaddition) would not have occurred otherwise, incomes will necessarily be increased and at a rate which will normally exceed the rate of increased investment. Moreover, except in conditions of full employment, there will be an increase of real income as well as of money-income.

  銀行は信用創造(=銀行が貸出をすること『マンキュー経済学II』p320)によって「真正な貯蓄」と何の対応もない投資を発生させているという考え方が あるが、それは銀行信用(=貸出金)の増加で起こる様々なことのうちの一つの事を取り立てて強調して他の事を無視した結果である。もしある企業家に対して 銀行信用が供与されて、既に存在する信用(=借入金)に追加されることによって、その企業家が現在の投資に対して他の方法では発生しないような追加の投資 を行うことができた場合には、必然的に総所得が増加する。しかも、それはふつう投資の増加率を上回る率で増えるのである。さらに、完全雇用の状態でなけれ ば、名目賃金も実質賃金も増えるのである(=信用創造に対応する貯蓄が可能となる)。

The public will exercise “a free choice” as to the proportion in which they divide their increase of income between saving and spending; and it is impossible that the intention of the entrepreneur who has borrowed in order to increase investment can become effective (except in substitution for investment by other entrepreneurs which would have occurred otherwise) at a faster rate than the public decide to increase their savings. Moreover, the savings which result from this decision are just as genuine as any other savings. No one can be compelled to own the additional money corresponding to the new bank-credit, unless he deliberately prefers to hold more money rather than some other form of wealth. Yet employment, incomes and prices cannot help moving in such a way that in the new situation someone does choose to hold the additional money.

社会はその所得の増加分を貯蓄と支出に振り分ける割合について「自由選択権」をもっている。しかも、企業家が借金(=信用創造)して投資を増やそうとして も(他の企業家が借金以外の方法で行えたはずの投資を代行するのでないかぎり)、社会が貯蓄を増やすことを決める前にそれを実行することは不可能である。 さらに、社会のこの決定から生まれる貯蓄はまさに他のどの貯蓄とも同じ真正な貯蓄である(=信用創造に対応する真正な貯蓄)。確かに、他の富の形態ではな くより多くの貨幣を意図的に保有(=貯蓄)しようとする場合は別として、新たな銀行信用(=信用創造)に対応する追加の貨幣を誰かに強制的に保有(=真正 な貯蓄を)させることは出来ない。しかし、雇用と所得と物価が変動していくと、新たな状況の中で必ず誰かが追加の貨幣を保有するようになるのである。

  It is true that an unexpected increase of investment in a particular direction may cause an irregularity in the rate of aggregate saving and investment which would not have occurred if it has been sufficiently foreseen. It is also true that the grant of the bank-credit will set up three tendencies (1) for output to increase, (2) for the marginal product to rise in value in terms of the wage-unit (which in conditions of decreasing return must necessarily accompany an increase of output), and (3) for the wage-unit to rise in terms of money (since this is a frequent concomitant(付随物) of better employment); and these tendencies may affect the distribution of real income between different groups. But these tendencies are characteristic of a state of increasing output as such, and will occur just as much if the increase in output has been initiated otherwise than by an increase in bank-credit. They can only be avoided, by avoiding any course of action capable of improving employment. Much of the above, however, is anticipating the result of discussions which have not yet been reached.

確かに、特定の方面での投資の予期せぬ増加は、総貯蓄と総投資の割合に不規則性を、しかも投資の増加が充分予想された場合には起こらないような不規則性を もたらすだろう。また、銀行信用の供与が次の三つの傾向をもたらすのは事実である。(1)産出量の増加、(2)単位賃金で測った限界生産物の価格の上昇 (収益の減少という状況ではそれは必然的に産出量の増加を伴う)、(3)名目単位賃金の上昇(これはしばしば雇用の改善に付随するからである)。しかもこ の三つの傾向は、異なる集団間への実質所得の分配に影響する可能性がある。しかし、これらは産出量が増加する状況それ自身の特徴であるから、産出量の増加 が銀行信用の増加以外の原因で始まった場合にも、同じようにこれらは発生する。これらの傾向を回避するには、雇用を改善させるようなあらゆる方針を回避す るしかない。しかし、上記の多くは今後行われる議論の結論を先取りするものである。

  Thus the old-fashioned view that saving always involves investment, though incomplete and misleading, is formally sounder than the newfangled(流行の) view that there can be saving without investment or investment without “genuine” saving. The error lies in proceeding to the plausible inference that, when an individual saves, he will increase aggregate investment by an equal amount. It is true, that, when an individual saves he increases his own wealth. But the conclusion that he also increases aggregate wealth fails to allow for the possibility that an act of individual saving may react on someone else's savings and hence on someone else's wealth.

  つまり、貯蓄はつねに投資を引き起こすという昔から存在する考え方は不完全であり紛らわしいものだが、投資なしの貯蓄、あるいは「真正な貯蓄」なしの投資 が存在しうるとする最近の物の見方よりは、明らかに健全である。個人が貯蓄するとき彼は総投資を同じ量だけ増やしているという妥当な結論に至るまでの過程 に間違いが存在するのだ。確かに、個人が貯蓄をするときに彼は自分の富を増やしている。しかし、彼は同時に富の総体を増やしているとする結論は、個人の貯 蓄行為が他の誰かの貯蓄に逆の作用を及ぼして(=減らす)、その結果、他の誰かの富に逆の作用を及ぼす(=他人の富を減らす)可能性を見落としている。

  The reconciliation of the identity between saving and investment with the apparent “free-will” of the individual to save what he chooses irrespective of what he or others may be investing, essentially depends on saving being, like spending, a two-sided affair. For although the amount of his own saving is unlikely to have any significant influence on his own income, the reactions of the amount of his consumption on the incomes of others makes it impossible for all individuals simultaneously to save any given sums. Every such attempt to save more by reducing consumption will so affect incomes that the attempt necessarily defeats itself. It is, of course, just as impossible for the community as a whole to save less than the amount of current investment, since the attempt to do so will necessarily raise incomes to a level at which the sums which individuals choose to save add up to a figure exactly equal to the amount of investment.

  貯蓄と投資が一致するという事実と、個人が自分や他人の投資量に無関係に好きなだけ貯蓄する明らかな「自由意志」とが調和するのは、本質的に貯蓄が支出と 同じく二面性のある出来事だからである。というのは、自分の貯蓄量が自分の所得に大きく影響しそうにないにもかかわらず、自分の消費量が他人の所得に作用 を及ぼす(=消費を減らして貯蓄を増やすと他人の所得を減らす)ため、すべての個人が同時に一定額の貯蓄をすることは不可能である(=合成の誤謬)。その ようにして消費を減らして貯蓄を増やそうとするあらゆる試みは、所得に影響を与えるので(=所得を減らせてしまうので)、その試みは必然的に失敗する。も ちろん社会全体が現在の投資量より少ない額の貯蓄(=多くの消費)をすることも同様に不可能である。なぜなら、そのような試みは必然的に所得を増加させつ づけて、個人が貯蓄しようとする額の総計が投資量とちょうど同じ数字になるレベルまで進むからである。

  The above is closely analogous with the proposition which harmonises the liberty, which every individual possesses, to change, whenever he chooses, the amount of money he holds, with the necessity for the total amount of money, which individual balances add up to, to be exactly equal to the amount of cash which the banking system has created. In this latter case the equality is brought about by the fact that the amount of money which people choose to hold is not independent of their incomes or of the prices of the things (primarily securities有価証券、債券), the purchase of which is the natural alternative to holding money. Thus incomes and such prices necessarily change until the aggregate of the amounts of money which individuals choose to hold at the new level of incomes and prices thus brought about has come to equality with the amount of money created by the banking system. This, indeed, is the fundamental proposition of monetary theory.

  すべての個人は自分が保有(=消費しない=貯蓄)する貨幣量を好きなときに変更する自由をもっているが、その一方で、個々の収支を総計した全貨幣量は必然 的に銀行が創造した現金量(=貨幣創造によって生まれた貨幣供給量)とちょうど一致する。前段の議論はこの自由と必然を調和させる命題と非常によく似てい る。後者の場合にこの一致が生まれるのは、人々が保有しようとする貨幣量は、自分の所得や物品(主に債券)ー貨幣を保有し続けない場合に当然購入する物ー の価格に制約されるという事実によるのである。つまり所得と債券価格は変化していって、それらが新たなレベルに達したとき個人が保有している貨幣量の総額 は必然的に最後には銀行が創造した貨幣量と等しくならざるを得ないのである。これは貨幣理論の根本命題である。

  Both these propositions follow merely from the fact that there cannot be a buyer without a seller or a seller without a buyer. Though an individual whose transactions are small in relation to the market can safely neglect the fact that demand is not a one-sided transaction, it makes nonsense to neglect it when we come to aggregate demand. This is the vital difference between the theory of the economic behaviour of the aggregate and the theory of the behaviour of the individual unit, in which we assume that changes in the individual's own demand do not affect his income.

  この二つの命題は単に「売り手がなければ買い手がない、買い手がなければ売り手がない」という事実から来ているに過ぎないのである。市場と比較して取引量 が少ない個人の場合には需要が一面的な取り引きではないという事実を無視しても問題はないが、総需要を扱うときにこの事実を無視するのはナンセンスであ る。これが総額としての経済行動の理論と個人単位の行動の理論との決定的な違いである。個人の行動においては彼の需要の変化は彼の所得に影響を与えないと 見なせるのである。

Author's Footnotes

[1]. My method there was to regard the current realised profit as determining the current expectation of profit.

[2]. Vide Mr. Robertson's article “Saving and Hoarding” (Economic Journal, September 1933, p. 399) and the discussion between Mr. Robertson, Mr. Hawtrey and myself (Economic Journal, December 1933, p. 658).

[3]. Quarterly Journal of Economics, Nov. 1932, p. 123.

[4]. Loc. cit. p. 125.

著者注

[1]  『貨幣論』における私の方法は、当期に実現された利潤が当期の予想利潤を決定すると見なしている。

[2]  ロバートソン氏の論文『貯蓄と貯蔵』(エコノミック・ジャーナル1933年9月399頁)と、私、ロバートソン氏そしてホートレー氏の間で行われた議論(エコノミック・ジャーナル1933年658頁)を見よ。

[3]  『クオーターリー・ジャーナル・オブ・エコノミスクス』(1932年11月123頁)

[4]  前掲書125頁。


Book III The Propensity to Consume

Chapter 8. The Propensity to Consume: I. The Objective Factors

第3巻 消費性向

第8章 消費性向 1 客観的要因

I

  WE are now in a position to return to our main theme, from which we broke off at the end of Book I in order to deal with certain general problems of method and definition. The ultimate object of our analysis is to discover what determines the volume of employment. So far we have established the preliminary conclusion that the volume of employment is determined by the point of intersection of the aggregate supply function with the aggregate demand function. The aggregate supply function, however, which depends in the main on the physical conditions of supply, involves few considerations which are not already familiar. The form may be unfamiliar but the underlying factors are not new. We shall return to the aggregate supply function in Chapter 20, where we discuss its inverse under the name of the employment function. But, in the main, it is the part played by the aggregate demand function which has been overlooked; and it is to the aggregate demand function that we shall devote Books III and IV.

第1節

  方法と定義という一般的な問題を扱うために第一巻の終わりで中断していたメインテーマにここで戻ることにしよう。我々の分析の最終的な目的は雇用量を決め るものは何かと決定することである。これまでのところでは、雇用量は総供給関数と総需要関数の交点で決まるという結論を我々は一応得ている。ところで、総 供給関数は主に物理的な供給条件によって決まるので、未知の検討課題はほとんど残っていない。関数の形式は珍しくても基本となる要素はよく知られているも のばかりである(=要素費用等々)。総供給関数については第20章でその逆関数を雇用関数として再び扱うことになる。それに対して、総需要関数が果たす役 割はこれまであまり検討してこなかった。そこで、我々は第3巻と第4巻を総需要関数の検討に充てようと思う。

  The aggregate demand function relates any given level of employment to the “proceeds” which that level of employment is expected to realise. The “proceeds” are made up of the sum of two quantities ― the sum which will be spent on consumption when employment is at the given level, and the sum which will be devoted to investment. The factors which govern these two quantities are largely distinct(大きく異なる). In this book we shall consider the former, namely what factors determine the sum which will be spent on consumption when employment is at a given level; and in Book IV we shall proceed to the factors which determine the sum which will be devoted to investment.

  総需要関数はある雇用レベルとそれが実現すると予想される売上を結びつける関数である。その売上は二種類の金額の合計である。つまり、総需要関数とはその 雇用レベルにおける消費支出と投資支出の合計である。この二つの種類の金額を決める要素はそれぞれに異なっている。この巻では、ある雇用レベルにおける消 費支出の額を決める要因について考える。そのあと第4巻では投資支出の額を決める要因について考えることになる。

  Since we are here concerned in determining what sum will be spent on consumption when employment is at a given level, we should, strictly speaking, consider the function which relates the former quantity (C) to the latter (N). It is more convenient, however, to work in terms of a slightly different function, namely, the function which relates the consumption in terms of wage-units (Cw) to the income in terms of wage-units (Yw) corresponding to a level of employment N.
 
  我々がここで問題にしているのはある雇用レベルの時にどれだけの消費支出があるかなので、厳密に言えば、我々は消費量を雇用量に結びつける関数を考えるべ きところである。しかしながら、少し異なる関数を扱うほうが都合が良い。それは雇用レベルの代わりにそれに対応する所得を考えて、ある雇用レベルNの時に 単位賃金数で測った消費Cwを単位賃金数で測った所得Ywに結びつける関数である。
 
This suffers from the objection that Yw is not a unique function of N, which is the same in all circumstances. For the relationship between Yw and N may depend (though probably in a very minor degree) on the precise nature of the employment. That is to say, two different distributions of a given aggregate employment N between different employments might (owing to the different shapes of the individual employment functions ― a matter to be discussed in Chapter 20 below) lead to different values of Yw. In conceivable circumstances(ある場合には、そういう状況もある) a special allowance might have to be made for this factor.

これには次のような反論が来るだろう。つまり、所得Ywと雇用数Nの関係はたった一つではなく、状況によって大きく異なるはずだ、というものである。とい うのは、所得Ywと雇用数Nの関係は雇用の正確な性質に(多分ごく僅かな程度)依存するからである。つまり、ある総雇用Nを2つの異なる雇用に配分すると (それぞれの雇用関数は異なってくる―これは第20章で扱う)所得の値Ywは異なってくる可能性があるからである。ある場合にはこの要因を特に考慮に入れ る必要も出てくる。

But in general it is a good approximation to regard Yw as uniquely determined by N. We will therefore define what we shall call the propensity to consume as the functional relationship χ between Yw a given level of income in terms of wage-units, and Cw the expenditure on consumption out of that level of income, so that

Cw = χ(Yw) or C = W.χ(Yw).

しかし、一般的には所得Ywは雇用数Nで一意的に決まってくると考えて概ね間違いない。したがって、我々が消費性向と呼ぶものは、単位賃金数で測った所得レベルYwとその所得レベルからの消費支出Cwとの間の関数関係χと定義する。そこで、

Cw=χ(Yw)あるいはC=W×χ(Yw)

となる。

  The amount that the community spends on consumption obviously depends (i) partly on the amount of its income, (ii) partly on the other objective attendant circumstances, and (iii) partly on the subjective needs and the psychological propensities and habits of the individuals composing it and the principles on which the income is divided between them (which may suffer modification as output is increased).

  社会の消費支出量は(一)所得に一部は依存し、(ニ)他の客観的な付帯状況に一部は依存し、(三)社会を構成する個人の主観的な要求、心理的な傾向と習慣、個人間に所得を分配する原則(これは産出量の増加によって変化する)に一部は依存する。

The motives to spending interact and the attempt to classify them runs the danger of false division. Nevertheless it will clear our minds to consider them separately under two broad heads which we shall call the subjective factors and the objective factors. The subjective factors, which we shall consider in more detail in the next Chapter, include those psychological characteristics of human nature and those social practices and institutions which, though not unalterable, are unlikely to undergo a material change over a short period of time except in abnormal or revolutionary circumstances. In an historical enquiry or in comparing one social system with another of a different type, it is necessary to take account of the manner in which changes in the subjective factors may affect the propensity to consume. But, in general, we shall in what follows take the subjective factors as given; and we shall assume that the propensity to consume depends only on changes in the objective factors.

支出の様々な動機は互いに影響しあうし、その様々な動機を分類しようとすると、間違った分類をして恐れがある。それでも、それらを主観的要因と客観的要因 の二つに分けて考えることは頭の整理になるだろう。主観的要因については次章で詳しく検討するが、その中には人間の性質の心理的な性格と社会慣習と社会制 度が含まれる。それらは不変ではないとしても、異常な環境や革命的な状況でもなければ短期間で大きく変化をすることはない。歴史的に研究する場合や異なっ た社会制度を比較研究する場合には、主観的要因の変化がどのように消費性向に影響を与えるかを検討する必要があるだろう。しかし、一般的に、以下において は、主観的要因は所与のものとして取り扱うことにする。そして、消費性向は客観的な要因の変化だけに依存するものと想定する。


II

The principal objective factors which influence the propensity to consume appear to be the following:

(1) A change in the wage-unit. ― Consumption (C) is obviously much more a function of (in some sense) real income than of money-income. In a given state of technique and tastes and of social conditions determining the distribution of income, a man's real income will rise and fall with the amount of his command(支配、制御) over labour-units(単位労働数), i.e. with the amount of his income measured in wage-units; though when the aggregate volume of output changes, his real income will (owing to the operation of decreasing returns) rise less than in proportion to his income measured in wage-units.

第2節

消費性向に影響を与える客観的な要因の主なものは次のとおりである。

(1)単位賃金(=所得)の変化 ― 消費(C)は名目所得の関数と言うよりは明らかに(ある意味で)実質所得の関数である。技術と嗜好、それに所得の分配を決める社会的な条件が所与のものと するとき、ある人の実質所得(=製品の価格で測った所得=製品の個数)は、彼が占める複数の単位労働数(=何時間労働したか)、すなわち単位賃金数(=例 えば時給×時間)で測った彼の所得(=上記のYw)に比例して上下する。ただし、総産出量が変化した時、(収穫逓減の法則のために)単位賃金数で測った所 得より実質所得は小さな割合で増えることになる(=生産物の数は労働時間数より増え方が少ない)。

As a first approximation, therefore, we can reasonably assume that, if the wage-unit changes, the expenditure on consumption corresponding to a given level of employment will, like prices, change in the same proportion; though in some circumstances we may have to make an allowance for the possible reactions(反作用) on aggregate consumption of the change in the distribution of a given real income between entrepreneurs and rentiers resulting from a change in the wage-unit. Apart from this, we have already allowed for changes in the wage-unit by defining the propensity to consume in terms of income measured in terms of wage-units.

したがって大雑把に言って、物価の変化と同じように、単位賃金が変化すると、ある雇用量に対応する消費支出も同じ割合で変化すると言ってよい。ただし、あ る環境においては、単位賃金の変化は利子生活者と企業家の間の実質所得の配分に変化をもたらし、その変化が総消費に逆向きの作用を及ぼす可能性があること を考慮する必要がある(=既出「単位賃金の変化は貸手と借手の間に所得の再分配をもたらす」)。これ以外にも、我々は既に消費性向を単位賃金数で測った所 得によって定義した時に、単位賃金の変化を考慮に入れている。

(2) A change in the difference between income and net income. We have shown above that the amount of consumption depends on net income rather than on income, since it is, by definition, his net income that a man has primarily in mind when he is deciding his scale of consumption. In a given situation there may be a somewhat stable relationship between the two, in the sense that there will be a function uniquely relating different levels of income to the corresponding levels of net income. If, however, this should not be the case, such part of any change in income as is not reflected in net income must be neglected since it will have no effect on consumption; and, similarly, a change in net income, not reflected in income, must be allowed for. Save in exceptional circumstances, however, I doubt the practical importance of this factor. We will return to a fuller discussion of the effect on consumption of the difference between income and net income in the fourth section of this chapter.

(2)所得と純所得の差額(=補足費用)の変化。上記で我々は消費量は所得ではなく純所得に依存することを示した。というのは、定義によって、人が消費の 規模を決めるときに第一に思い浮かべるのは自分の純所得であるからである。ある状況では所得と純所得の間には安定した関係が見られる場合がある。それは様 々なレベルの所得とそれに対応する純所得を一意的に結びつける関数が存在するという意味である。しかしながら、たとえそうでなくても、所得の変化のうちで 純所得に反映されない部分は無視しなければならない。なぜなら、その部分は消費に影響しないからである。また、同様に、所得に反映されない純所得の変化は 考慮に入れなければならない。しかしながら、例外的な環境を除いて、この要素の実際的な重要性に私は疑いを持っている。所得と純所得の差額が消費に与える 影響については、後にこの章の第四節でもっと詳しく議論する。

(3) Windfall changes in capital-values not allowed for in calculating net income. ― These are of much more importance in modifying the propensity to consume, since they will bear no stable or regular relationship to the amount of income. The consumption of the wealth-owning class may be extremely susceptible to unforeseen changes in the money-value of its wealth. This should be classified amongst the major factors capable of causing short-period changes in the propensity to consume.

(3)純所得の計算には考慮されない資本価値の偶発的変化 ― この変化は消費性向を変化させるうえでさらに重要である。というのは、この変化と所得量の間には安定した規則的関係はないからである。富裕階級の消費は彼 らの富がもつ貨幣価値の予測できない変化に極度に影響を受けやすい。この要素は消費性向に短期間に変化を引き起こす可能性があると考えるべきである。

(4) Changes in the rate of time-discounting, i.e. in the ratio of exchange between present goods and future goods. ― This is not quite the same thing as the rate of interest, since it allows for future changes in the purchasing power of money in so far as these are foreseen. Account has also to be taken of all kinds of risks, such as the prospect of not living to enjoy the future goods or of confiscatory taxation. As an approximation, however, we can identify this with the rate of interest.

(4)期限割引率の変化。つまり、現在の財と将来の財の交換比率の変化。― 期限割引率は利子率と全く同じというわけではない。なぜなら、期限割引率の変化には、予想できるかぎりにおいて将来の貨幣の購買力の変化が含まれているか らである。また将来の財を享受するまで生きていない可能性や重税が課される可能性など、あらゆるリスクも考慮されねばならない。しかし、大雑把に言えば。 これは利子率(=利子率)を同じだと考えることが出来る。

  The influence of this factor on the rate of spending out of a given income is open to a good deal of doubt. For the classical theory of the rate of interest,[1] which was based on the idea that the rate of interest was the factor which brought the supply and demand for savings into equilibrium, it was convenient to suppose that expenditure on consumption is cet. par. negatively sensitive to changes in the rate of interest, so that any rise in the rate of interest would appreciably diminish consumption. It has long been recognised, however, that the total effect of changes in the rate of interest on the readiness to spend on present consumption is complex and uncertain, being dependent on conflicting tendencies, since some of the subjective motives towards saving will be more easily satisfied if the rate of interest rises, whilst others will be weakened. Over a long period substantial changes in the rate of interest probably tend to modify social habits considerably, thus affecting the subjective propensity to spend ― though in which direction it would be hard to say, except in the light of actual experience.

 所得からの支出量に対するこの要素の影響については大きな疑問の声があがっている。利子率についての古典派の理論は[1]、利子率が貯蓄の需要と供給を 均衡させる要因であるという考えに基いているので、その理論にとっては、消費支出は他の事情が同じならば利子率の変化には反比例して、利子率の上昇は消費 を下げると考えるのが好都合である。しかしながら、今期の消費支出に対する利子率の包括的な影響は、相反する傾向に依存しているので、複雑で不明確である ということが、ずっと前から認識されてきている。というのは、利子率が上がっても、主観的な貯蓄の動機のうちには、容易に満たされるものもあれば弱められ るものもあるからである。長期間の後には利子率の大きな変化が社会の習慣を大きく変えて、消費支出傾向にも影響を与える場合がある。ただし、どの方向に変 えるかは実際の経験に照らしてみなければ分からない。

The usual type of short-period fluctuation in the rate of interest is not likely, however, to have much direct influence on spending either way. There are not many people who will alter their way of living because the rate of interest has fallen from 5 to 4 per cent, if their aggregate income is the same as before. Indirectly there may be more effects, though not all in the same direction. Perhaps the most important influence, operating through changes in the rate of interest, on the readiness to spend out of a given income, depends on the effect of these changes on the appreciation or depreciation in the price of securities and other assets. For if a man is enjoying a windfall increment in the value of his capital, it is natural that his motives towards current spending should be strengthened, even though in terms of income his capital is worth no more than before; and weakened if he is suffering capital losses. But this indirect influence we have allowed for already under (3) above. Apart from this, the main conclusion suggested by experience is, I think, that the short-period influence of the rate of interest on individual spending out of a given income is secondary and relatively unimportant, except, perhaps, where unusually large changes are in question. When the rate of interest falls very low indeed, the increase in the ratio between an annuity purchasable for a given sum and the annual interest on that sum may, however, provide an important source of negative saving by encouraging the practice of providing for old age by the purchase of an annuity.

通常タイプの利子率の短期変動は支出に対して直接どの方向にも影響を与えることはない。総所得が同じなら利子率が5%から4%に下がったからと言って暮し 向きを変える人は多くない。間接的な影響はあるかもしれないが、同じ方向への影響とは限らない。利子率の変化が所得の支出に対して与える恐らく最も大きな 影響は、債券などの資産価格の高騰あるいは低下に対して利子率の変化がどのように影響するかで決まる。というのは、自分の資本の価値が偶発的に増加した場 合、たとえ所得としては自分の資本価値に変化がなくても、当期の支出の動機は強められるし、資本に損失が出たら支出の動機が弱まるのは当然である。しか し、この間接的な影響は(3)で既に検討済みである。これを別としても経験が示唆する主な結論は、個人の所得の支出に対する利子率の短期の影響は、二次的 で比較的重要性を欠く。しかし、異常に大きな変化が起きた時はそうではない。実際、利子率が大きく下がった時には、ある金額で購入できる年金で毎年もらえ る金額の方がその金額で稼げる毎年の利子よりも大きくなるので、老後に備えて年金を買うという習慣が促進されて、その結果、負の貯蓄(=資産の取り崩し、 この場合は貯金の解約)がよく促進されるようになるかもしれない。

  The abnormal situation, where the propensity to consume may be sharply affected by the development of extreme uncertainty concerning the future and what it(将来) may bring forth, should also, perhaps, be classified under this heading.

  消費性向が将来に対する大きな不安が広がることで急激な影響を受ける異常な状況は多分この括りに含まれる。

(5) Changes in fiscal policy. ― In so far as the inducement to the individual to save depends on the future return which he expects, it clearly depends not only on the rate of interest but on the fiscal policy of the Government. Income taxes, especially when they discriminate against “unearned” income, taxes on capital-profits, death-duties and the like are as relevant as the rate of interest; whilst the range of possible changes in fiscal policy may be greater, in expectation at least, than for the rate of interest itself. If fiscal policy is used as a deliberate instrument for the more equal distribution of incomes, its effect in increasing the propensity to consume is, of course, all the greater.[2]

(5)財政政策の変化 ― 個人の貯蓄性向を左右するものが予想される将来の利息である場合には、その性向は明らかに利子率だけでなく政府の財政政策にも影響を受ける。貯蓄性向に とっては、所得税、特に不労所得にかかる所得税、資本利得税、相続税などは利子率と同じように重要である。その一方、財政政策の変化の幅、少なくともそれ に対する期待の変化の幅は、利子率の変化の幅よりも大きい。もし所得の公平な配分のための意図的な道具として財政政策が使われるなら、消費性向を強める効 果はもちろん大きくなる[2]。

We must also take account of the effect on the aggregate propensity to consume of Government sinking funds(減債基金、負債償却積立金) for the discharge of debt(負債の返済) paid for out of ordinary taxation. For these represent a species of corporate saving(法人貯蓄), so that a policy of substantial sinking funds must be regarded in given circumstances as reducing the propensity to consume. It is for this reason that a change-over from a policy of Government borrowing to the opposite policy of providing sinking funds (or vice versa) is capable of causing a severe contraction (or marked expansion) of effective demand.

通常の租税から支払われる公債償還のための減債基金が総消費性向に及ぼす効果も考慮されねばならない。なぜなら、減債基金というものは一種の法人貯蓄のよ うな働きをするので、ある環境のもとでは巨大な減債基金の政策は消費性向を低下させると見做さねばならない。この理由のために、政府が借入れ政策から正反 対の減債基金を置く政策へ変更(あるいはその逆)すると有効需要の激しい縮小(あるいは明確な拡張)をもたらす可能性があるのである。

(6) Changes in expectations of the relation between the present and the future level of income. ― We must catalogue this factor for the sake of formal completeness. But, whilst it may affect considerably a particular individual's propensity to consume, it is likely to average out for the community as a whole. Moreover, it is a matter about which there is, as a rule, too much uncertainty for it to exert much influence.

(6) 現在の所得水準と将来の所得水準との間の関係についての予想の変化 ― この要素をここに並べるのは形式的な完成度のためである。しかし、これは特定の個人の消費性向に大きく影響する一方で、社会全体としては平均化されるだろ う。さらに、この問題が大きな影響力を持つためにはあまりにも不確実な要素が大きすぎる。

  We are left therefore, with the conclusion that in a given situation the propensity to consume may be considered a fairly stable function, provided that we have eliminated changes in the wage-unit in terms of money. Windfall changes in capital-values will be capable of changing the propensity to consume, and substantial changes in the rate of interest and in fiscal policy may make some difference; but the other objective factors which might affect it, whilst they must not be overlooked, are not likely to be important in ordinary circumstances.

  したがって、貨幣で測った単位賃金の変化がないと仮定した場合、所与の状況では消費性向はかなり安定した関数であるという結論に至る。資本価値の偶発的変 化は消費性向を変化させる可能性があるし、利子率と財政政策の大きな変化はある程度の変化をもたらすだろう。しかし、消費性向に影響する他の客観的な要因 は、無視する訳にはいかないが、通常の環境においては重要ではない。

  The fact that, given the general economic situation, the expenditure on consumption in terms of the wage-unit depends in the main[,] on the volume of output and employment is the justification for summing up the other factors in the portmanteau(色んな性質を持った) function “propensity to consume”. For whilst the other factors are capable of varying (and this must not be forgotten), the aggregate income measured in terms of the wage-unit is, as a rule, the principal variable upon which the consumption-constituent of the aggregate demand function will depend.

  一般的な経済状況において、単位賃金で測った消費支出が主に産出量と雇用量に依存するという事実は、それ以外の要素は「消費性向関数」という色んな性質を もつ関数の中に含めてもよいということを意味する。というのは、他の要素が変化するとしても(これは忘れてはいけない)、基本的には単位賃金で測った総所 得が主な変数であり、総需要関数のうちの消費はこの変数に依存するからである。

III

  Granted(以上から仮に), then, that the propensity to consume is a fairly stable function so that, as a rule, the amount of aggregate consumption mainly depends on the amount of aggregate income (both measured in terms of wage-units), changes in the propensity itself being treated as a secondary influence, what is the normal shape of this function?

第3節

   以上から、消費性向関数は変動の少ない関数であり、基本的には主に総所得量が総消費量(両者は単位賃金数で測ったものである)を決定し、消費性向自体の変 化がそこに脇から影響を与えると見なすならば、消費性向関数の標準的な形はどのようなものになるだろうか。

  The fundamental psychological law, upon which we are entitled to depend with great confidence both a priori from our knowledge of human nature and from the detailed facts of experience, is that men are disposed, as a rule and on the average, to increase their consumption as their income increases, but not by as much as the increase in their income. That is to say, if Cw is the amount of consumption and Yw is income (both measured in wage-units) ΔCw has the same sign as ΔYw but is smaller in amount, i.e. dCw/dYw is positive and less than unity.

  人間の本質と経験的な事実から我々が大きな信頼を置ける基本的心理法則は、所得が増えれば消費も増えるが、消費の増加量は所得の増加量よりも小さいという ことである。つまり、Cwを消費量Ywを所得とすると(両者とも単位賃金数で測った値)、ΔCwとΔYwは同じ符号をもっておりΔCwはΔYwよりも少な い、即ちdCw/dYwは1より小さい正の数である。

  This is especially the case where we have short periods in view, as in the case of the so-called cyclical fluctuations of employment <,>during which habits, as distinct from more permanent psychological propensities, are not given time enough to adapt themselves to changed objective circumstances. For a man's habitual standard of life usually has the first claim on his income, and he is apt to save the difference which discovers itself between his actual income and the expense of his habitual standard; or, if he does adjust his expenditure to changes in his income, he will over short periods do so imperfectly. Thus a rising income will often be accompanied by increased saving, and a falling income by decreased saving, on a greater scale at first than subsequently.

  これは短期を視野に考えるときに特に当てはまる。短期というのは例えば雇用の周期的は変動がそうである。それは客観情勢の変化に(もっと恒久的な心理的傾向とは違って)習慣的な事でさえも適応できないような期間である。というのは、人は普通自分の所得からまず第一に習慣的な生活レベルを維持するために支出する。そして、その生活水準を維持するための支出と自分の所得の差額を貯蓄に回すのである。あるいは、もし彼が自分の所得の変化に支出を適応させるとしても、短期間ではそれをうまく出来ないだろう。つまり、所得が上がると貯蓄も上がるだろうし、所得が減ると貯蓄も減るだろう(=消費は変わらない)。しかも、その同調する規模は最初は大きく、後に小さくなっていくだろう。

  But, apart from short-period changes in the level of income, it is also obvious that a higher absolute level of income will tend, as a rule, to widen the gap between income and consumption. For the satisfaction of the immediate primary needs of a man and his family is usually a stronger motive than the motives towards accumulation, which only acquire effective sway when a margin of comfort has been attained. These reasons will lead, as a rule, to a greater proportion of income being saved as real income increases.

 一方、所得レベルの短期の変化は別としても、所得レベルが絶対的に高くなると所得と消費の差が広がる傾向があるのも明らかである。というのは、普通は自 分と家族の今すぐの必要を満たす欲求のほうが貯蓄の欲求よりも強いものであり、ある程度楽な生活が出来るようになって初めて貯蓄の欲求が生まれるからであ る。こういう次第で、所得が増えるに従ってより大きな所得の割合が貯蓄されるようになるのである。

But whether or not a greater proportion is saved, we take it as a fundamental psychological rule of any modern community that, when its real income is increased, it will not increase its consumption by an equal absolute amount, so that a greater absolute amount must be saved, unless a large and unusual change is occurring at the same time in other factors.

その一方で、より大きな所得の割合が貯蓄されるか否かに関わらず、近代社会では実質所得が増えても、消費はそれと丁度同じ量だけ増えないのは、近代社会の 本質的な心理法則であって、その結果、他の要素に大きな変化がない限り、実質所得が増えると必ず貯蓄(=消費しない分)の絶対量が増加するのである。

As we shall show subsequently,[3] the stability of the economic system essentially depends on this rule prevailing in practice. This means that, if employment and hence aggregate income increase, not all the additional employment will be required to satisfy the needs of additional consumption.

あとで示すように[3]、経済機構が安定していることは、本質的にはこの法則が現実に浸透しているおかげである。このことは、雇用とそれに伴う総所得が増 加した場合、増加した消費の需要を満たすためには、雇用の増加分の全てを振り向ける必要はないということを意味する(第3章第2節に既出)。

On the other hand, a decline in income due to a decline in the level of employment, if it goes far, may even cause consumption to exceed income not only by some individuals and institutions using up the financial reserves(個人貯蓄と法人貯蓄) which they have accumulated in better times, but also by the Government, which will be liable, willingly or unwillingly, to run into a budgetary deficit or will provide unemployment relief, for example, out of borrowed money.

他方、雇用レベルの低下のために所得が低下して、それが進んでいった場合には、消費が所得をオーバーしてしまうことも起こりうる(=消費の低下は所得の低 下に同調しない)。それは、好調の時に蓄えた個人と機関の貯蓄でまかなわれる場合もあれば、政府によってまかなわれる場合もある。後者の場合は、好むと好まざるに関わらず、赤字予算となる。つまり、例えば失業率を下げるために借金をするのである。

Thus, when employment falls to a low level, aggregate consumption will decline by a smaller amount than that by which real income has declined, by reason both of the habitual behaviour of individuals and also of the probable policy of governments; which is the explanation why a new position of equilibrium can usually be reached within a modest range of fluctuation. Otherwise a fall in employment and income, once started, might proceed to extreme lengths.

つまり、雇用が低下して実質所得が低下しても、総消費はそれよりは少ない量しか減らないのである。それは個人の習慣的な行動様式(=貯蓄)のためだけめなく、政府のありうべき政策(=借金)のためである。このために、それほど大きな変動を経ずに新たな均衡に至るのである。さもなければ、雇用と所得の低下は一旦始まると極端な程度にまで進んでしまうだろう。

This simple principle leads, it will be seen, to the same conclusion as before, namely, that employment can only increase pari passu with an increase in investment; unless, indeed, there is a change in the propensity to consume. For since consumers will spend less than the increase in aggregate supply price when employment is increased, the increased employment will prove unprofitable unless there is an increase in investment to fill the gap.

  この単純な原理のおかげで、他の条件が同じならば、雇用の増加は投資の増加と歩調を合わせるという、以前と同じ結論に至ることがわかるだろう。というの は、雇用が増加した場合にも、消費支出は総供給価格(=所得)よりも少いので、この2つの差を埋める投資の増加がなければ、雇用の増加は不利となるからで ある。

IV

  We must not underestimate the importance of the fact already mentioned above that, whereas employment is a function of the expected consumption and the expected investment, consumption is, cet. par.(=ceteris paribus他の事情が同じならば), a function of net income, i.e. of net investment (net income being equal to consumption plus net investment). In other words, the larger the financial provision(金銭的な備え) which it is thought necessary to make before reckoning net income, the less favourable to consumption, and therefore to employment, will a given level of investment prove to be.

第4節

  雇用は消費と投資の予想値の関数であるが、その一方で、消費は他の事情が同じならば純所得の関数であり、それは即ち純投資の関数である(純所得は消費と純 投資の和に等しい)。この事実は既に述べたものだが(第3章2節(3)、第7章3節)、その重要性を決して軽視してはならない。言い換えれば、純所得を計 算する前に取りのけておく必要のある準備金が大きくなればなるだけ、投資が消費に与える効果も雇用に与える効果も小さくなってしまう。

  When the whole of this financial provision (or supplementary cost) is in fact currently expended in the upkeep of the already existing capital equipment, this point is not likely to be overlooked. But when the financial provision exceeds the actual expenditure on current upkeep(維持), the practical results of this in its effect on employment are not always appreciated. For the amount of this excess neither directly gives rise to current investment nor is available to pay for consumption.

  この準備金(つまり補足費用)が既存の資本設備の維持に全額支出されている間は、この問題は大したことではない。しかし、補足費用が当期の維持費を超えて 多すぎて余った場合に、それが現実の雇用に与える影響はしばしば見落とされてきた。というのは、この超過分は当期の投資を生み出すわけでもなく、消費に回 されることもないからである。

 It has, therefore, to be balanced by new investment, the demand for which has arisen quite independently of the current wastage of old equipment <,>against which the financial provision is being made; with the result that the new investment available to provide current income is correspondingly diminished and a more intense demand for new investment is necessary to make possible a given level of employment. Moreover, much the same considerations apply to the allowance for wastage included in user cost, in so far as the wastage is not actually made good.

そのために、この余った分は新たな投資によって埋め合わせる必要がある。その新たな投資への需要は古い設備の消耗とは関係なく発生したものでなければなら ない。その消耗に備えて補足費用が設定されているが、その結果、当期の所得をもたらすはずの新規投資はそれだけ減額されてしまっており、ある雇用レベルを 維持するためには、新規投資へのさらに大きな需要が必要となるのである。さらに、使用費用の中に含まれている消耗引当金についても、それが実際に出費され ない場合には、まったく同じ懸念が当てはまる。

  Take a house which continues to be habitable until it is demolished or abandoned. If a certain sum is written off its value out of the annual rent paid by the tenants, which the landlord neither spends on upkeep(維持) nor regards as net income available for consumption, this provision(準備金、蓄え), whether it is a part of U or of V, constitutes a drag(邪魔) on employment all through the life of the house, suddenly made good in a lump(まとめて) when the house has to be rebuilt.

  壊されるか廃棄されるまで住み続けられる家を考えてみよう。もし家賃収入の内から借家の価値を一定額ずつ取り除けていき、それを家主が借家の維持にも使わ ず純所得として消費にも回さなかった場合には、この準備金は、∪の一部であろうと∨の一部であろうと、その家の寿命の続く限り雇用の妨げになり、家が建て 替えられる時に突然まとめて支出されるのである。

  In a stationary economy all this might not be worth mentioning, since in each year the depreciation allowances in respect of old houses would be exactly offset by the new houses built in replacement of those reaching the end of their lives in that year. But such factors may be serious in a non-static economy, especially during a period which immediately succeeds a lively burst of investment in long-lived capital. For in such circumstances a very large proportion of the new items of investment may be absorbed by the larger financial provisions made by entrepreneurs in respect of existing capital equipment, upon the repairs and renewal of which, though it is wearing out with time, the date has not yet arrived for spending anything approaching the full financial provision which is being set aside; with the result that incomes cannot rise above a level which is low enough to correspond with a low aggregate of net investment.
 
  定常的な経済ではこうしたことの全ては言及する価値はないかもしれない。なぜなら、古い家の毎年の減価償却の引当金は、その年その年に寿命がつきた家が順 に新しい家に建て替えられることによって相殺されるからである。しかし、この要素は動的な経済では重要なものである。特に長い寿命をもつ資本に対して活発 な投資が行われた直後の期間はそうである。というのは、そのような状況では、新しい投資項目の大部分は、企業家たちが現在の投資設備のために設定したさら に大きな準備金によって吸収されてしまうからである。その設備は時間とともに損耗するが、修理や買い替えのために設定された準備金の全額に近い額を使う期 日はまだ到来していないので、所得は低い純投資(A1-U-V)の総額に対応する低いレベルを留まってしまう。
 
Thus sinking funds, etc., are apt to withdraw spending power from the consumer long before the demand for expenditure on replacements (which such provisions are anticipating) comes into play; i.e. they diminish the current effective demand and only increase it in the year in which the replacement is actually made. If the effect of this is aggravated by “financial prudence”, i.e. by its being thought advisable to “write off”(減価償却として取り除けておく) the initial cost(初期投資費用⇔維持管理費用ランニングコスト) more rapidly than the equipment actually wears out, the cumulative result may be very serious indeed.
 
つまり、減債基金等のおかげで(そのような準備金が予定している)買い替え需要が動き出すまでの長い間、消費者の支出力が取り上げられてしまう傾向がある のである。このような準備金のおかげで当期の有効需要を減ってしまい、買い替えが実現する年になったようやく有効需要が増えるである。もしこの結果が「財 政的用心」つまり設備の消耗よりも先に初期投資費用を減価償却として取り除けておくことによってさらに悪化するなら、累積的な結果は非常に深刻なものとな る。
 
  In the United States, for example, by 1929 the rapid capital expansion of the previous five years had led cumulatively to the setting up of sinking funds and depreciation allowances, in respect of plant which did not need replacement, on so huge a scale that an enormous volume of entirely new investment was required merely to absorb these financial provisions; and it became almost hopeless to find still more new investment on a sufficient scale to provide for such new saving as a wealthy community in full employment would be disposed to set aside. This factor alone was probably sufficient to cause a slump. And, furthermore, since “financial prudence” of this kind continued to be exercised through the slump by those great corporations which were still in a position to afford it, it offered a serious obstacle to early recovery.

  例えば、合衆国では1929年まではそれまでの5年間の急速な資本の拡張の結果、買い替えが必要でないプラントのために、減債基金と減価償却引当金が積立 てられて、それが非常に大規模だったので、これらの準備金を吸収するだけに新規の莫大な額の投資が必要となった。そして、完全雇用である豊かな社会が取り 除けておく新たな貯蓄に備えて、さらに大きな新投資を充分な規模で見つけるなど殆ど絶望的となったのである。この要因だけでも充分に景気後退の理由になっ た。その上さらに、この種の「財政的用心」は不景気の間も余裕のある大企業によって実施され続けたために、早期の景気回復にとって大きな障害となったので ある。

  Or again, in Great Britain at the present time (1935) the substantial amount of house-building and of other new investments since the war has led to an amount of sinking funds being set up much in excess of any present requirements for expenditure on repairs and renewals, a tendency which has been accentuated, where the investment has been made by local authorities and public boards, by the principles of “sound” finance which often require sinking funds sufficient to write off the initial cost some time before replacement will actually fall due; with the result that even if private individuals were ready to spend the whole of their net incomes it would be a severe task to restore full employment in the face of this heavy volume of statutory provision by public and semi-public authorities, entirely dissociated from any corresponding new investment.

  あるいはまた、英国では戦後家屋の建築など膨大な量の新たな投資が行われた結果、現在(1935年)では修理や買い替えに必要な額を超えた減債基金が設定 されている。この傾向は、投資が地方公共団体によって行われた場合には、買い替え時期が来る前に初期投資費用を減価償却として取り除けさせる「健全財政」 の方針によって強められた。その結果、個人が自分の純所得を全部支出しようとしても、公共機関と準公共機関による巨大な法定準備金を前に、それに対応する 新たな投資がまったく伴わない状態で完全雇用を回復するのは至難の業である。

The sinking funds of local authorities now stand, I think,[4] at an annual figure of more than half the amount which these authorities are spending on the whole of their new developments.[5] Yet it is not certain that the Ministry of Health are aware, when they insist on stiff sinking funds by local authorities, how much they may be aggravating the problem of unemployment. In the case of advances by Building Societies to help an individual to build his own house, the desire to be clear of debt more rapidly than the house actually deteriorates may stimulate the house-owner to save more than he otherwise would; ― though this factor should be classified, perhaps, as diminishing the propensity to consume directly rather than through its effect on net income. In actual figures, repayments of mortgages advanced by Building Societies, which amounted to £24,000,000 in 1925, had risen to £68,000,000 by 1933, as compared with new advances of £103,000,000; and to-day the repayments are probably still higher.

地方公共団体の減債基金は今では毎年新たな開発に支出する全金額の半分以上[4]に達していると思われる[5]。しかし、健康省が地方団体に堅苦しい減債 基金を要求することで失業問題をどれほど悪化させているかを知っているのだろうか。建設協会が個人の住宅建設を援助する融資の場合は、家が劣化する前に借 金を返したいという欲求のおかげで、他の場合より家の持ち主の貯蓄欲が促進される。もっとも、この要因は消費性向を直接減少させるものであって、純所得へ の効果を通じて消費性向を減らすものではない。実際の数字では建設協会からの借入金の返済額は1925年に2400万ポンドだったものが、1933年には 新規の融資が1億300万ポンドになったのに合わせて6800万ポンドにまでのぼり、今日では恐らくそれ以上だろう。

  That it is investment, rather than net investment, which emerges from the statistics of output, is brought out forcibly and naturally in Mr. Colin Clark's National Income, 1924-1931. He also shows what a large proportion depreciation, etc., normally bears to the value of investment. For example, he estimates that in Great Britain, over the years 1928-1931,[6] the investment and the net investment were as follows, though his gross investment is probably somewhat greater than my investment, inasmuch as it may include a part of user cost, and it is not clear how closely his “net investment” corresponds to my definition of this term:

  投入産出統計に現れている数字は純投資量ではなく粗投資量であることは、コーリン・クラーク氏の研究『1924から1931年の国民所得』が明らかにして いる。また、同氏は粗投資量のどれだけ多くの部分を減価償却等が占めているかも示している。例えば、1928年から1931年[6]の英国の投資と純投資 を以下のように計算してる。ただし、彼の粗投資は使用費用を含んでいるので私の定義した投資より大きいし、彼の「純投資」は私の用語にどれだけ近いかは明 らかではない。

                                                 (£ million)
                                                 1928    1929    1930    1931
Gross Investment-Output                           791     731     620     482
“Value of physical wasting of old capital”     433     435     437     439
Net Investment                                   358     296     183      43

                                                 (100万ポンド)
                                                 1928    1929    1930    1931
粗投入産出量                                      791      731      620      482
「旧資本の物的損耗値」                            433      435      437      439
純投資                                            358      296      183        43


  Mr. Kuznets has arrived at much the same conclusion in compiling the statistics of the Gross Capital Formation (as he calls what I call investments) in the United States1919-1933. The physical fact(中身), to which the statistics of output correspond, is inevitably the gross, and not the net, investment. Mr. Kuznets has also discovered the difficulties in passing from gross investment to net investment. “The difficulty”, he writes, “of passing from gross to net capital formation, that is, the difficulty of correcting for the consumption of existing durable commodities, is not only in the lack of data. The very concept of annual consumption of commodities that last over a number of years suffers from ambiguity”.[7] He falls back, therefore, “on the assumption that the allowance for depreciation and depletion on the books of business firms describes correctly the volume of consumption of already existing' finished durable goods used by business firms”. On the other hand, he attempts no deduction(償却費) at all in respect of houses and other durable commodities in the hands of individuals. His very interesting results for the United States can be summarised as follows:

                                            (Millions of Dollars)
                              1925      1926      1927      1928      1929
Gross capital formation
 (after allowing for
 net change in business
 inventories)                    30,706    33,571    31,157    33,934    34,491
Entrepreneurs' servicing,
 repairs, maintenance,
 depreciation and depletion      7,685     8,288  8,223  8,481       9,010
 
Net capital formation
 (on Mr. Kuznets'definition)    23,021    25,293    22,934    25,453    25,481

     (Millions of Dollars)
                                 1930      1931       1932       1933
Gross capital formation
(after allowing for net
change in business
inventories)                    27,538    19,721    7,780      14,879

Entrepreneurs' servicing,
repairs, maintenance,
depreciation and depletion      8,502  7,623  6,543      8,204

Net capital formation
(on Mr. Kuznets' definition)    19,036 11,098  1,237 6,675


  クズネッツ氏も『合衆国の1919年から1933年の粗資本形成』(投資と私が呼ぶものを氏はこう呼ぶ)の統計でほぼ同じ結論に達している。この統計の数 字の実際の中身は当然純投資ではなく粗投資である。クズネッツ氏はまた粗投資から純投資を導き出すことが困難だと言っている。彼は「粗投資から純投資を導 き出すこと、つまり現存耐久財の消耗分を補正するのが難しいのは、データがないからだけではない。数年間にわたって継続する毎年の財の消耗という考え方は 非常に曖昧だからである」[7]と書いている。したがって、彼は「企業の帳簿の減価償却引当金と消耗引当金が現存耐久財の消耗量を正確に表していると想定 する」ことにした。一方、彼は個人所有の家屋や耐久財については償却費を差し引こうとしていない。合衆国について彼が行った興味深い計算結果は以下のよう に要約できる。


                                   (単位100万ドル)
                                  1925       1926        1927       1928       1929
粗資本形成
 (企業在庫の純変化を勘案後)  30,706    33,571     31,157    33,934    34,491
企業家の点検、補修、維持、
 減価、損耗の償却費               7,685    8,288    8,223    8,481      9,010
純資本形成
 (クズネッツ氏の定義による)     23,021    25,293     22,934    25,453    25,481

                                    (単位100万ドル)
                                     1930       1931        1932        1933
粗資本形成
 (企業在庫の純変化を勘案後) 27,538    19,721     7,780      14,879
企業家の点検、補修、維持、
 減価、損耗 の償却費              8,502   7,623     6,543        8,204
純資本形成
 (クズネッツ氏の定義による)     19,036 11,098     1,237     6,675

Several facts emerge with prominence from this table. Net capital formation was very steady over the quinquennium 1925-1929, with only a 10 per cent increase in the latter part of the upward movement. The deduction for entrepreneurs' repairs, maintenance, depreciation and depletion remained at a high figure even at the bottom of the slump. But Mr. Kuznets' method must surely lead to too low an estimate of the annual increase in depreciation, etc.; for he puts the latter at less than 1 1/2 per cent per annum of the new net capital formation. Above all, net capital formation suffered an appalling collapse after 1929, falling in 1932 to a figure no less than 95 per cent below the average of the quinquennium 1925-1929.

この表から色んな事が分かってくる。純資本形成は1925年から1929年までの5年間は安定しており、この上昇期の後半でもわずかに10%増加しただけ である。企業家の点検、補修、維持、減価、損耗などの償却費は不景気のどん底でも高いレベルを保っている。しかし、クズネッツ氏の方法では償却費の毎年の 増加は過剰に低く抑えられる。というのは、彼は償却費の毎年の増加を新たな純資本形成のうちの1.5%以下に設定しているからである。とにかく、純資本形 成は1929年が終わると崩壊して1932年の値は1925年から1929年の5年間の平均値の95%も下回っている。

  The above is, to some extent, a digression. But it is important to emphasise the magnitude of the deduction which has to be made from the income of a society, which already possesses a large stock of capital, before we arrive at the net income which is ordinarily available for consumption. For if we overlook this, we may underestimate the heavy drag on the propensity to consume which exists even in conditions where the public is ready to consume a very large proportion of its net income.

  以上は少々脱線である。しかし、大きな資本ストックをすでに持っている社会で、通常は消費に使える純所得を計算するまえに、所得から控除されるべき償却費 の大きさを強調しておくことは重要である。というのは、もしこの事実を見逃すと、社会が既に純所得のうちの非常に多くの部分を消費しようとしている状況に おいて、なお消費性向を妨げる巨大なものが存在することを過小評価することになる。

  Consumption ― to repeat the obvious ― is the sole end and object of all economic activity. Opportunities for employment are necessarily limited by the extent of aggregate demand. Aggregate demand can be derived only from present consumption or from present provision for future consumption. The consumption for which we can profitably provide in advance cannot be pushed indefinitely into the future. We cannot, as a community, provide for future consumption by financial expedients but only by current physical output. In so far as our social and business organisation separates financial provision for the future(準備金) from physical provision for the future so that efforts to secure the former do not necessarily carry the latter with them, financial prudence will be liable to diminish aggregate demand and thus impair well-being, as there are many examples to testify. The greater, moreover, the consumption for which we have provided in advance, the more difficult it is to find something further to provide for in advance, and the greater our dependence on present consumption as a source of demand. Yet the larger our incomes, the greater, unfortunately, is the margin between our incomes and our consumption. So, failing some novel expedient, there is, as we shall see, no answer to the riddle, except that there must be sufficient unemployment to keep us so poor that our consumption falls short of(不足する→所得から消費を引いたものが) our income by no more than the equivalent of the physical provision for future consumption which it pays to produce to-day.

  当たり前のことを繰り返すが、消費は全ての経済活動の唯一の目的であり目標である。雇用機会は総需要の大きさによって必然的に制約されるが、総需要をもた らすのは現在の消費だけである。あるいはまた将来の消費に対して現在準備(=機械の生産)することもそうであるが、それは将来有利になるように準備した消 費は永遠に引き伸ばすことは出来ないからである。社会として我々が将来の消費のために行える準備は金融的な手段(=準備金)によってではなく現在の物理的 な産出(=機械の生産)によってだけである。我々の社会やビジネス組織は将来への金融的な準備と物理的な準備を切り離したので、前者を確保する努力では必 ずしも同時に後者を確保できない。そういう状況では多くの例が証明するように、経済的用心深さは総需要を減らし社会の厚生を損ないがちである。さらに、将 来の消費への準備(=機械の生産)が大きくなるほど、それ以上の将来のための準備を見つけることは難しいし、需要源としての現在の消費の役割は大きくな る。しかし、不幸なことに、所得が大きくなるに連れて、所得と消費の差は大きくなる。だから、何か斬新な方法がないと、これから見るように、この問題に対 する答えはない。ただし、我々は大量に失業して非常な所得不足になれば、所得から現在の消費を引いたものが、今日生産する事が利益になる「将来の消費への 物理的準備」と全く等しくなるとだけは言える。

  Or look at the matter thus. Consumption is satisfied partly by objects produced currently and partly by objects produced previously, i.e. by disinvestment. To the extent that consumption is satisfied by the latter, there is a contraction of current demand, since to that extent a part of current expenditure fails to find its way back as a part of net income. Contrariwise whenever an object is produced within the period with a view to satisfying consumption subsequently(後の、将来), an expansion of current demand is set up. Now all capital-investment is destined to result, sooner or later, in capital-disinvestment.

 しかし、それがだめならこういう見方もある。消費は今期の生産物と以前の生産物即ちマイナス投資(=在庫の消耗)によって満たされる。消費が後者によっ て満たされる分だけ、当期の需要は縮小する。なぜなら、その分だけ当期の支出は純所得に戻ってこないからである。逆にいえば、ある生産物が将来の消費を満 たすために今期内に作られるとき、今期の需要が拡張するのである。つまり、あらゆる資本投資は遅かれ早かれ資本のマイナス投資となる運命にあるのである。
 
Thus the problem of providing that new capital-investment shall always outrun capital-disinvestment sufficiently to fill the gap between net income and consumption, presents a problem which is increasingly difficult as capital increases. New capital-investment can only take place in excess of current capital-disinvestment if future expenditure on consumption is expected to increase. Each time we secure to-day's equilibrium by increased investment<,> we are aggravating the difficulty of securing equilibrium to-morrow. A diminished propensity to consume to-day can only be accommodated to the public advantage if an increased propensity to consume is expected to exist some day. We are reminded of “The Fable of the Bees” ― the gay of to-morrow are absolutely indispensable to provide a raison d'e^tre for the grave of to-day.

つまり、資本のマイナス投資を凌駕するような新たな資本投資によって、純所得と消費の差が広まるのを防ぐようにするという問題は、資本が増加するに従って ますます困難となる。新たな資本投資が資本のマイナス投資を超えて行われるには、将来の消費支出が増加すると期待される時だけである。我々は今日の均衡を 手に入れるために投資を増やすたびに、明日の均衡を手に入れることを難しくしているのである。いつか消費性向が増加すると期待できないかぎり、今日減少し た消費性向を社会の利益と調和させることはできない。我々は『蜂の寓話』(=18世紀にマンデヴィル作、節約を批判する内容、二三章七節で詳説)を思い出す。今日の憂鬱が存在理由を持つためには明日の陽気さが絶対に無くてはならないのだ。

  It is a curious thing, worthy of mention, that the popular mind seems only to be aware of this ultimate perplexity where public investment is concerned, as in the case of road-building and house-building and the like. It is commonly urged as an objection to schemes for raising employment by investment under the auspices of public authority that it is laying up trouble for the future. “What will you do,” it is asked, “when you have built all the houses and roads and town halls and electric grids and water supplies and so forth which the stationary population of the future can be expected to require?” But it is not so easily understood that the same difficulty applies to private investment and to industrial expansion; particularly to the latter, since it is much easier to see an early satiation of the demand for new factories and plant which absorb individually but little money, than of the demand for dwelling-houses.

奇妙なことだが、言っておくべき事は、道路建設や住宅建設などの公共投資に関するかぎり、人々の心はこの究極の難問に気づいているようである。一般的に、 公共機関の支援で行う投資による雇用増加計画は、将来の困難をためこむと反対される事が多い。「家と道路と公会堂と送電線と水道設備など将来の安定した人 口が必要とすると予想されるものを全部作ってしまったら、その後どうするつもりなのか?」と問われるのだ。しかし、この同じ困難が民間投資や産業の発展に も当てはまることは、それほど容易には理解されない。特に後者にはこの問題がつきまとう。なぜなら、住宅の需要よりも、個別には殆どお金を吸収しない新たな工場やプラントの需要が早々に満たされるのは見易い事実だからである。

The obstacle to a clear understanding is, in these examples, much the same as in many academic discussions of capital, namely, an inadequate appreciation of the fact that capital is not a self-subsistent entity existing apart from consumption. On the contrary, every weakening in the propensity to consume regarded as a permanent habit must weaken the demand for capital as well as the demand for consumption.

これらの例の理解を妨げているものは、資本に関する多くの学術的な理論の場合と同じである。それはすなわち、資本とは消費から切り離された自己完結的な存 在ではないという事実を充分に理解していないことである。それどころか、不変の習慣とみなされている消費性向が弱まるたびに、消費の需要だけではなく資本 の需要も必ず弱まるのである。

Author's Footnotes

[1]. Cf. Chapter 14 below.

[2]. It may be mentioned, in passing, that the effect of fiscal policy on the growth of wealth has been the subject of an important misunderstanding which, however, we cannot discuss adequately without the assistance of the theory of the rate of interest to be given in Book IV.

[3]. Cf. p. 251 below.

[4]. The actual figures are deemed of so little interest that they are only published two years or more in arrears.

[5]. In the year ending March 31, 1930, local authorities spent £87,000,000 on capital account, of which £37,000,000 was provided by sinking funds, etc., in respect of previous capital expenditure; in the year ending March 31, 1933, the figures were £81,000,000 and £46,000,000.

[6]. Op. cit. pp. 117 and 138.

[6] 前掲書 117頁と138頁。 

[7]. These references are taken from a Bulletin (No. 52) of the National Bureau of Economic Research, giving preliminary results of Mr. Kuznets' forthcoming book.

著者注

[1] 14章参照。

[2] 序でに言っておくと、富の増加に対する財政政策の影響は重要な誤解のテーマとなってきたが、第4巻で扱う利子率の理論の助けなしには充分に論じることはできない。

[3] 251頁参照。

[4] 実際の数字は重視されていないので2年以上遅れて公開されている。

[5] 1930年3月31日で終わる年度に、地方公共団体は8千7百万ドルを資本勘定で支出しているが、そのうちの3千7百万ドルは以前の資本支出に対 する減債基金等によって拠出されている。1933年3月31日で終わる年度には、その数字は8千1百万ドルと4千6百万ドルである。

[7] この言葉はクズネッツ氏の近刊書の予備的結果を掲載している全米経済研究所の紀要52号からとった。

 
Chapter 9. The Propensity to Consume: II. The Subjective Factors

第9章 消費性向 2 主観的な要因

I

  THERE remains the second category of factors which affect the amount of consumption out of a given income, namely, those subjective and social incentives which determine how much is spent, given the aggregate of income in terms of wage-units and given the relevant objective factors which we have already discussed. Since, however, the analysis of these factors raises no point of novelty, it may be sufficient if we give a catalogue of the more important, without enlarging on them at any length.

第1節

  消費の所得に占める量に影響する要因の二つ目のカテゴリーは、どれだけ消費するかを決める主観的で社会的な動機である。その際、単位賃金数で測った総所得 と既に述べたこれに関連する客観的な要因は所与のものとする。しかし、主観的要素の分析には新しい論点はないので、その中でも比較的重要なものを並べて簡 単な説明を加えれば充分だろう。

  There are, in general, eight main motives or objects of a subjective character which lead individuals to refrain from spending out of their incomes:

(i) To build up a reserve against unforeseen contingencies;

(ii) To provide for an anticipated future relation between the income and the needs of the individual or his family different from that which exists in the present, as, for example, in relation to old age, family education, or the maintenance of dependents;

(iii) To enjoy interest and appreciation, i.e. because a larger real consumption at a later date is preferred to a smaller immediate consumption;

(iv) To enjoy a gradually increasing expenditure, since it gratifies a common instinct to look forward to a gradually improving standard of life rather than the contrary, even though the capacity for enjoyment may be diminishing;

(v) To enjoy a sense of independence and the power to do things, though without a clear idea or definite intention of specific action;

(vi) To secure a masse de manoeuvre(仏、予備金) to carry out speculative or business projects;

(vii) To bequeath a fortune;

(viii) To satisfy pure miserliness, i.e. unreasonable but insistent inhibitions against acts of expenditure as such.

人が自分の所得からの出費を控える主観的な目的ないし動機は主に八つある。

(一)不測の事態に備えるため。

(二)現在とは異なる将来の予想される所得と出費の関係に備えるため。例えば、老後の生活、家族の教育、扶養家族の生活など、家族や個人の将来の必要に備える。

(三)利子や価値の上昇を楽しむため。なぜなら、少額の消費をすぐにするより実質的に高額な消費をあとでするほうが望ましいから。

(四)支出が次第に増えることを楽しむため。なぜなら、楽しみは次第に減っていくにもかかわらず、生活水準が次第に向上することへの期待は誰の本能も満足することだから。

(五)何か具体的にしようという計画はなくても、自律感と有能感を得るため。

(六)投機的あるいは経営上の企画を実行するための大量の運用資金を確保するため。

(七)財産を遺すため。

(八)純粋な貪欲を満たすため。消費支出そのものに反対する不合理な抑制心。

  These eight motives might be called the motives of Precaution, Foresight, Calculation, Improvement, Independence, Enterprise, Pride and Avarice; and we could also draw up a corresponding list of motives to consumption such as Enjoyment, Short-sightedness, Generosity, Miscalculation, Ostentation and Extravagance.

  消費を控えるこれら八つの動機は、用心、深慮、打算、向上、独立、企業、自尊、貪欲と呼ぶことが出来る。これに対して、消費を行う動機は、享楽、浅慮、寛大、誤算、虚飾、浪費である。

  Apart from the savings accumulated by individuals, there is also the large amount of income, varying perhaps from one-third to two-thirds of the total accumulation in a modern industrial community such as Great Britain or the United States, which is withheld by Central and Local Government, by Institutions and by Business Corporations ― for motives largely analogous to, but not identical with, those actuating individuals, and mainly the four following:

(i) The motive of enterprise ― to secure resources to carry out further capital investment without incurring debt or raising further capital on the market;

(ii) The motive of liquidity ― to secure liquid resources to meet emergencies, difficulties and depressions;

(iii) The motive of improvement ― to secure a gradually increasing income, which, incidentally, will protect the management from criticism, since increasing income due to accumulation is seldom distinguished from increasing income due to efficiency;

(iv) The motive of financial prudence and the anxiety to be “on the right side” by making a financial provision in excess of user and supplementary cost, so as to discharge debt and write off the cost of assets ahead of, rather than behind, the actual rate of wastage and obsolescence, the strength of this motive mainly depending on the quantity and character of the capital equipment and the rate of technical change.

  個人が蓄える貯蓄のほかに、英国や米国のような近代産業社会では、中央政府と地方政府、民間機関や営利企業によって大量の所得が保持されている。これは個 人の蓄えを含めた全ての蓄えの3分の1から3分の2に達する。この蓄えを動機は個人の場合と全く同じではないが類似の動機に基づいている。

(一)企業的動機―市場で資本を調達せず借金もせずに投資を増やす資金を確保するため。

(二)流動性(=初出、現金および換金可能性の高いこと)の動機―緊急事態や困難や不況に備えて流動性資産を確保するため。

(三)改良の動機―所得を次第に増加させるため。ちなみに、所得の増加は蓄えに依る場合も効率化による場合も区別できないので、経営を批判から守ることができる。

(四)財政的な慎重さと、使用費用と補足費用以上の金銭的な蓄えをすることで「黒字経営」を維持しようとする願い。これは負債を支払い、資産の損耗や旧式 化の速度に遅れないように、むしろ先立って費用を償却するためである。この動機の強さは主に資産設備の量と性格、および技術的な変化のレベルに依存する。

  Corresponding to these motives which favour the withholding of a part of income from consumption, there are also operative at times motives which lead to an excess of consumption over income. Several of the motives towards positive saving catalogued above as affecting individuals have their intended counterpart in negative saving at a later date, as, for example, with saving to provide for family needs or old age. Unemployment relief financed by borrowing is best regarded as negative saving.

  所得の一部の消費を控えるこれらの動機に対応して、時にはまた所得を超えた消費をする動機が存在する。上記に列挙した動機の多くは個人の場合にはプラスの 貯蓄を促すものであるが、例えば家族の必要や老後のための貯蓄の場合には、それが後になってマイナスの貯蓄を促す動機ともなる。失業対策を借入金で賄え ば、それはマイナス貯蓄と見なすのがよい。

  Now the strength of all these motives will vary enormously according to the institutions and organisation of the economic society which we presume, according to habits formed by race, education, convention, religion and current morals, according to present hopes and past experience, according to the scale and technique of capital equipment, and according to the prevailing distribution of wealth and the established standards of life. In the argument of this book, however, we shall not concern ourselves, except in occasional digressions, with the results of far-reaching social changes or with the slow effects of secular progress. We shall, that is to say, take as given the main background of subjective motives to saving and to consumption respectively. In so far as the distribution of wealth is determined by the more or less permanent social structure of the community, this also can be reckoned a factor, subject only to slow change and over a long period, which we can take as given in our present context.

  これら全ての動機の強さは、我々が想定する経済社会の機関や組織によって、民族・教育・慣習・宗教・道徳が形成した習慣によって、現在の希望と過去の経験 によって、資本設備の規模と技術によって、支配的な富の分配の仕方と一般的な生活水準によって、大きく変化する。しかし、本書では、時々脱線するときのほ かは、社会的な変化の先々の効果や、長年に渡る進歩の遅れた効果については扱わない。つまり、貯蓄と消費のそれぞれについての主観的な動機の主要な背景は 所与のものとして扱うのである。ある程度恒久的な社会構造によって決まっている富の分配については、変化が遅く長期間にわたるものなので、これもまた我々 の文脈では所与の要因と見なすことが出来る。

II

  Since, therefore, the main background of subjective and social incentives changes slowly, whilst the short-period influence of changes in the rate of interest and the other objective factors is often of secondary importance, we are left with the conclusion that short-period changes in consumption largely depend on changes in the rate at which income (measured in wage-units) is being earned and not on changes in the propensity to consume out of a given income.

第2節

  したがって、主観的かつ社会的インセンティブの変化はゆっくりしており、その一方で、利子率や他の客観的要因の変化の短期的影響はあまり重要ではないの で、短期における消費の変化が依存するのは主に所得(単位賃金数で測った)の量の変化であって、所得に対する消費性向の変化ではないという結論に至らざる を得ない。

  We must, however, guard against a misunderstanding. The above means that the influence of moderate changes in the rate of interest on the propensity to consume is usually small. It does not mean that changes in the rate of interest have only a small influence on the amounts actually saved and consumed. Quite the contrary. The influence of changes in the rate of interest on the amount actually saved is of paramount importance, but is in the opposite direction to that usually supposed. For even if the attraction of the larger future income to be earned from a higher rate of interest has the effect of diminishing the propensity to consume, nevertheless we can be certain that a rise in the rate of interest will have the effect of reducing the amount actually saved.

しかし、ここで誤解をしてはいけない。上記の意味は、利子率の穏やかな変化が消費性向に与える影響は普通は小さいということであって、実際に貯蓄される額 と消費される額への利子率の変化の影響が小さいということではない。逆である。実際の貯蓄高への利子率の変化の影響は極めて大きいのであるが、それは普通 に考えられているのと正反対なのである。とうのは、たとえ高い利子率から得られる将来の大きな所得の魅力が消費性向を下げる効果があるとしても、それにも かかわらず、利子率の上昇は実際の貯蓄高を減らす効果があるのである。

For aggregate saving is governed by aggregate investment; a rise in the rate of interest (unless it is offset by a corresponding change in the demand-schedule for investment) will diminish investment; hence a rise in the rate of interest must have the effect of reducing incomes to a level at which saving is decreased in the same measure as investment. Since incomes will decrease by a greater absolute amount than investment, it is, indeed, true that, when the rate of interest rises, the rate of consumption will decrease. But this does not mean that there will be a wider margin for saving. On the contrary, saving and spending will both decrease.

というのは、総貯蓄は総投資次第だからである。利子率の上昇は(それに対応する投資需要表の変化によって相殺されない限りは)投資を減らす。ということ は、利子率の上昇は所得を減らして、投資が減るのと同じだけ貯蓄も減るということである。所得は投資より絶対量で大きく減少するので、確かに、利子率が上 昇すれば、消費が減る。しかし、これは貯蓄の余地が広がるという意味ではない。貯蓄と消費が両方とも減るのである。

  Thus, even if it is the case that a rise in the rate of interest would cause the community to save more out of a given income, we can be quite sure that a rise in the rate of interest (assuming no favourable change in the demand-schedule for investment) will decrease the actual aggregate of savings. The same line of argument can even tell us by how much a rise in the rate of interest will, cet. par., decrease incomes. For incomes will have to fall (or be redistributed) by just that amount which is required, with the existing propensity to consume, to decrease savings by the same amount by which the rise in the rate of interest will, with the existing marginal efficiency of capital, decrease investment. A detailed examination of this aspect will occupy our next chapter.

  つまり、利子率の上昇によって社会が所得の中からより多く貯蓄しようとするのが事実だとしても、(投資需要表の有利な変化がないとすると)利子率の上昇に よって実際の総貯蓄が減るのは確実なのである。同様に考えていくと、他の条件が同じなら、利子率の上昇によって所得がどれだけ減るかも分かるのである。と いうのは、現行の資本の限界効率のもとで、利子率の上昇によって投資が減るが、それは貯蓄が減る量と同じであり、現状の消費性向のもとで、それだけ貯蓄が 減るためには、ちょうどその量だけ所得が減らなければ(再配分されなければ)ならないからである。この点の詳しい検証は次の章で行われる。
 
The rise in the rate of interest might induce us to save more, if our incomes were unchanged. But if the higher rate of interest retards investment, our incomes will not, and cannot, be unchanged. They must necessarily fall, until the declining capacity to save has sufficiently offset the stimulus to save given by the higher rate of interest. The more virtuous we are, the more determinedly thrifty, the more obstinately orthodox in our national and personal finance, the more our incomes will have to fall when interest rises relatively to the marginal efficiency of capital. Obstinacy can bring only a penalty and no reward. For the result is inevitable.

もし我々の所得に変化がなければ、利子率の上昇によって貯蓄を増やしたい気になるかもしれない。しかし、もし高い利子率によって投資が抑制されると、我々 の所得は不変ではないし、不変ではありえない。所得は必ず減って行き、貯蓄する力が落ちて高い利子率に刺激された貯蓄欲がなくなるのである。我々がみな道 徳的であり、倹約家であり、国の財政と家計に関して頑固な正統派であるなら、利子率が資本の限界効率(=予想収益率)よりも上昇したときには(=投資が減 るから)我々の所得は減らざるをえないのである。頑固さには何の報酬もない。ただ罰を受けるだけである。なぜなら、結果は避けられないからである。

Thus, after all, the actual rates of aggregate saving and spending do not depend on Precaution, Foresight, Calculation, Improvement, Independence, Enterprise, Pride or Avarice. Virtue and vice play no part. It all depends on how far the rate of interest is favourable to investment, after taking account of the marginal efficiency of capital[1]. No, this is an overstatement. If the rate of interest were so governed as to maintain continuous full employment, Virtue would resume her sway; ― the rate of capital accumulation would depend on the weakness of the propensity to consume. Thus, once again, the tribute that classical economists pay to her is due to their concealed assumption that the rate of interest always is so governed.

つまり、結局のところ、実際の貯蓄量と消費量は、用心、深慮、打算、向上、独立、企業心、自尊、貪欲とは関係がないのである。道徳も悪徳も何も関係がな い。その全ては、資本の限界効率[1]との比較の上で、利子率が投資にとってどれほど有利な値であるかにかかっているのだ。いや、これは言いすぎだ。もし 完全雇用が維持されるように利子率がコントロールされているなら、道徳が支配権を取り戻して、資本の蓄積額は消費性向の弱さ(=節約は美徳)に依存するよ うになるだろう。つまり、もう一度繰り返すと、古典派経済学者たちは、完全雇用を維持するように利子率がコントロールされていると無意識のうちに想定して いるからこそ、道徳を讃えるのである。

Author's Footnotes

[1]. In some passages of this section we have tacitly anticipated ideas which will be introduced in Book IV.

著者注

[1]この節の中のいくつかの文章には第4巻に出てくる考え方がそれとなく先取りされている。


Chapter 10. The Marginal Propensity to Consume and the Multiplier

第10章 限界消費性向と乗数

WE established in Chapter 8 that employment can only increase pari passu with investment. We can now carry this line of thought a stage further.

第8章において我々は、他の条件が同じならば、雇用は投資と歩調をあわせて増加することを確認した。今や我々はこの考えをさらに進めていくことができる。

For in given circumstances a definite ratio, to be called the Multiplier(乗数), can be established between income and investment and, subject to certain simplifications, between the total employment and the employment directly employed on investment (which we shall call the primary employment). This further step is an integral part of our theory of employment, since it establishes a precise relationship, given the propensity to consume, between aggregate employment and income and the rate of investment.

というのは、一定の環境においては、「乗数」という名の明確な比率が、所得と投資の間に、そしてある種の単純化を経ることによって、総雇用と投資による直 接雇用(これを我々は一次雇用と呼ぶ)の間に確立できるからである。この段階こそは我々の雇用の理論の中心となる部分となる。なぜなら、ここで我々は、一 定の消費性向のもとで、総雇用と所得と投資量の間に正確な関係を確立するからである。

The conception of the multiplier was first introduced into economic theory by Mr. R. F. Kahn in his article on “The Relation of Home Investment to Unemployment” (Economic Journal, June 1931). His argument in this article depended on the fundamental notion that, if the propensity to consume in various hypothetical circumstances is (together with certain other conditions) taken as given and we conceive the monetary or other public authority to take steps to stimulate or to retard investment, the change in the amount of employment will be a function of the net change in the amount of investment; and it aimed at laying down general principles by which to estimate the actual quantitative relationship between an increment of net investment and the increment of aggregate employment which will be associated with it. Before coming to the multiplier, however, it will be convenient to introduce the conception of the marginal propensity to consume.

乗数概念はR.F.カーン氏が「国内投資と失業の関係」(エコノミック・ジャーナル誌1931年6月号)において経済理論に最初に導入したものである。こ の論文の中心となる考え方は、多様な仮定的環境のもとで(他の条件も含めて)消費性向を所与のものとして、金融当局などの公共組織が投資を刺激したり鈍ら せたりする手段を取るとき、雇用量の変化は純投資量の変化の関数であるというものである。それは純投資の増加とそれに伴う総雇用の増加の間の実際の量的関 係を測定する一般的な原理を打ち立てることを目指すものである。しかしながら、乗数概念の話に行く前に、限界消費性向という考え方を導入しておくのが便利 だろう。

I

  The fluctuations in real income under consideration in this book are those which result from applying different quantities of employment (i.e. of labour-units) to a given capital equipment, so that real income increases and decreases with the number of labour-units employed. If, as we assume in general, there is a decreasing return at the margin as the number of labour-units employed on the given capital equipment is increased, income measured in terms of wage-units will increase more than in proportion to the amount of employment, which, in turn, will increase more than in proportion to the amount of real income measured (if that is possible) in terms of product.

第1節

  本書で考えられている実質所得の変動は、資本設備に様々な雇用量(つまり単位労働数)を適用した結果であり、雇用された単位労働数によって実質所得は増減 するのである。もし普通に考えられるように、資本施設に雇用される単位労働数が増えるにしたがって限界収益が逓減するなら、単位賃金数で測った所得(=利 潤込みの労働時間数)が雇用量(=賃金の労働時間数)より大きな割合で増えて、次に、雇用量が(可能なら)生産物で測った実質所得(=生産数)より大きな 割合で増えるだろう(=『コンメンタールp96に逆の順で同様の記述。第8章第2節にも既出)。

Real income measured in terms of product and income measured in terms of wage-units will, however, increase and decrease together (in the short period when capital equipment is virtually unchanged). Since, therefore, real income, in terms of product, may be incapable of precise numerical measurement, it is often convenient to regard income in terms of wage-units (Yw) as an adequate working index of changes in real income. In certain contexts we must not overlook the fact that, in general, Yw increases and decreases in a greater proportion than real income; but in other contexts the fact that they always increase and decrease together renders them virtually interchangeable.

しかしながら、生産物で測った実質所得と単位賃金数で測った所得は一緒に増減する(資本設備が不変である短期の場合)。そこで、生産物で測った実質所得は 正確な数字では表せないので、単位賃金数で測った所得(Yw)を実質所得の変化の有効な指標として使うのが便利である。確かに、一般的に、Ywは実質所得 より大きな割合で増減することを見逃すべきではない場合がある。しかし、それ以外の場合には、この2つが一緒に増減することから、この2つは実質的に代替 可能なのである。

Our normal psychological law that, when the real income of the community increases or decreases, its consumption will increase or decrease but not so fast, can, therefore, be translated ― not, indeed, with absolute accuracy but subject to qualifications which are obvious and can easily be stated in a formally complete fashion ― into the propositions that ΔCw and ΔYw have the same sign, but ΔYw > ΔCw, where Cw is the consumption in terms of wage-units. This is merely a repetition of the proposition already established on p. 29 above.

社会の実質所得が増減する時それに応じた社会の消費の増減幅はそれより少ないというのが我々の通常の心理法則だが、それはΔCwとΔYwは同じ符号を持っ ておりΔYw>ΔCw(Cwは単位賃金数で測った消費量)であるという命題に翻訳できる(この翻訳には完璧な正確さはなく、形式的に完全な形で容易に表わ される明確な条件が付く)。これは上記29頁(=三章二節(8))で既に確認した命題の繰り返しである。

Let us define, then, dCw/dYw as the marginal propensity to consume.

This quantity is of considerable importance, because it tells us how the next increment of output will have to be divided between consumption and investment. For ΔYw = ΔCw + ΔIw, where ΔCw and ΔIw are the increments of consumption and investment; so that we can write ΔYw = kΔIw, where 1 - (1/k) is equal to the marginal propensity to consume.

Let us call k the investment multiplier. It tells us that, when there is an increment of aggregate investment, income will increase by an amount which is k times the increment of investment.

そこで、dCw/dYwを「限界消費性向」と定義しよう。

この量はとても重要である。なぜなら、この量は産出物の次の増加がどのように消費と投資に分割されるかを教えているからである。というのは、ΔYw= ΔCw+ΔIw(ΔCwとΔIwは消費と投資の増加)だからである。そこで、ΔYw=kΔIwと表すと、1-(1/k)は限界消費性向に等しい(←1ー ΔIw/ΔYw=ΔCw/ΔYw)。

このkを投資乗数と呼ぼう。それは総投資が増加したとき、所得は投資の増加のk倍だけ増えるという意味である。

II

  Mr. Kahn's multiplier is a little different from this, being what we may call the employment multiplier designated by k', since it measures the ratio of the increment of total employment which is associated with a given increment of primary employment in the investment industries. That is to say, if the increment of investment ΔIw leads to an increment of primary employment ΔN2 in the investment industries, the increment of total employment ΔN = k'ΔN2.

第2節

  カーン氏の乗数はこれとは若干異なっており、彼の乗数は雇用乗数と呼べるもので、それはk'で表わすことができる。というのは、彼の乗数は、投資産業にお ける一次雇用の増加とそれに伴う総雇用の増加の割合を示しているからである。つまり、もし投資の増加ΔIwが投資産業に一次雇用の増加ΔN2をもたらすな ら、総雇用の増加ΔNはk'×ΔN2と等しくなる。

There is no reason in general to suppose that k = k'. For there is no necessary presumption that the shapes of the relevant portions of the aggregate supply functions for different types of industry are such that the ratio of the increment of employment in the one set of industries to the increment of demand which has stimulated it will be the same as in the other set of industries.[1] It is easy, indeed, to conceive of cases, as, for example, where the marginal propensity to consume is widely different from the average propensity, in which there would be a presumption <in favour of some inequality between> ΔYw/ΔN and ΔIw/ΔN2, since there would be very divergent proportionate changes in the demands for consumption-goods and investment-goods respectively.

一般にk=k'であると考える理由はない。というのは、異なる産業に関連する部分の総供給関数の形状が同じで、ある産業部門の雇用の増加とその増加を刺激 した需要の増加の比率が、他の産業部門と同じとなると想定する必要はないからである[1] 。確かに、例えば、限界消費性向が平均消費性向と大きく異なっていて、消費財の需要と投資財の需要の変化率が非常に違っているので、ΔYw/ΔNと ΔIw/ΔN2が一致しない場合を想像することは容易い(?)。

  If we wish to take account of such possible differences in the shapes of the relevant portions of the aggregate supply functions for the two groups of industries respectively, there is no difficulty in rewriting the following argument in the more generalised form. But to elucidate the ideas involved, it will be convenient to deal with the simplified case where k = k'.
 
  もし総供給関数の中の二つの産業部門に関連する部分の形状がそれほど異なっているという可能性を考慮に入れたければ、以下の議論をもっと一般的な形で書き 換えることは難しいことではない。しかし、そこに含まれている考え方を明らかにするには、k=k'である単純化した場合を扱うのが便利である。

  It follows, therefore, that, if the consumption psychology of the community is such that they will choose to consume, e.g., nine-tenths of an increment of income,[2] then the multiplier k is 10; and the total employment caused by (e.g.) increased public works will be ten times the primary employment provided by the public works themselves, assuming no reduction of investment in other directions. Only in the event of the community maintaining their consumption unchanged in spite of the increase in employment and hence in real income, will the increase of employment be restricted to the primary employment provided by the public works. If, on the other hand, they seek to consume the whole of any increment of income, there will be no point of stability and prices will rise without limit. With normal psychological suppositions, an increase in employment will only be associated with a decline in consumption if there is at the same time a change in the propensity to consume ― as the result, for instance, of propaganda in time of war in favour of restricting individual consumption; and it is only in this event that the increased employment in investment will be associated with an unfavourable repercussion on employment in the industries producing for consumption.

したがって、もし社会の消費心理が所得の増加の例えば10分の9を消費するつもりなら[2]、乗数kは10となる。すると、(例えば)公共工事の増加がも たらす総雇用は、他の分野への投資の削減がない限り、公共工事自体がもたらす一次雇用の10倍である。雇用の増加が公共工事のもたらす一次雇用に限られる ことがあるのは、雇用が増加して実質所得が増えたにもかかわらず、社会がその消費を不変に保ち続ける場合だけである。一方、もし所得の増加のすべてを社会 が消費しようとするなら、安定が取り戻されることはなく、物価は際限なく上昇する。普通の心理状態を仮定するかぎり、雇用が増加して消費が減少するのは同 時に消費性向が変化した場合だけである。例えば、戦時に個人消費を控えるように宣伝が行われた場合がそうである。投資による雇用の増加が、消費財産業の雇 用に対してよい影響を与えないのは、こういう場合だけである。

  This only sums up in a formula what should by now be obvious to the reader on general grounds. An increment of investment in terms of wage-units cannot occur unless the public are prepared to increase their savings in terms of wage-units. Ordinarily speaking, the public will not do this unless their aggregate income in terms of wage-units is increasing, Thus their effort to consume a part of their increased incomes will stimulate output until the new level (and distribution) of incomes provides a margin of saving sufficient to correspond to the increased investment.

  ここでしていることは、今では一般の読者にとって明らかなことをまとめているにすぎない。単位賃金数で測った投資の増加が起きるのは、社会が単位賃金数で 測った貯蓄の増加に積極的な場合だけである。普通に言って、大衆が貯蓄に積極的になるのは、単位賃金数で測った総所得が増加する場合だけである。つまり、 大衆は新たな所得レベルに到達して、投資の増加に対応する貯蓄をするだけの充分な力をもつまで、増えた所得の一部を消費して産出を刺激する努力を続けるの である。

The multiplier tells us by how much their employment has to be increased to yield an increase in real income sufficient to induce them to do the necessary extra saving, and is a function of their psychological propensities.[3] If saving is the pill and consumption is the jam, the extra jam has to be proportioned to the size of the additional pill. Unless the psychological propensities of the public are different from what we are supposing, we have here established the law that increased employment for investment must necessarily stimulate the industries producing for consumption and thus lead to a total increase of employment which is a multiple of the primary employment required by the investment itself.

乗数が我々に教えるのは、どれほど雇用が増えたら充分に実質所得が増加して、大衆は必要とされる余分の貯蓄をする気にをなるかということである。つまり、 乗数とは大衆の心理傾向(=消費性向)の関数なのである[3]。もし貯蓄が丸薬で消費がジャムなら、余分のジャムは追加の丸薬の大きさに比例しなければな らない。もし社会の心理傾向が我々の想定と異ならないなら、ここで我々は、投資による雇用の増加は消費財産業を刺激して総雇用の増加を導くが、それは投資 が要求した一次雇用のある数倍である、という法則を確立したのである。

  It follows from the above that, if the marginal propensity to consume is not far short of unity, small fluctuations in investment will lead to wide fluctuations in employment; but, at the same time, a comparatively small increment of investment will lead to full employment. If, on the other hand, the marginal propensity to consume is not much above zero, small fluctuations in investment will lead to correspondingly small fluctuations in employment; but, at the same time, it may require a large increment of investment to produce full employment. In the former case involuntary unemployment would be an easily remedied malady, though liable to be troublesome if it is allowed to develop. In the latter case, employment may be less variable but liable to settle down at a low level and to prove recalcitrant to any but the most drastic remedies.
 
  これまでのところから次のことがわかる。もし限界消費性向が1よりあまり小さくないなら、投資の僅かな変動は雇用の大きは変動を引き起こす。しかし、それ と同時に、比較的僅かな投資の増加で完全雇用が達成できる。それに対して、もし限界消費性向がゼロよりあまり大きくないなら、投資の僅かな変動は雇用の比 較的小さな変動を引き起こす。しかし、それと同時に、大きな投資の追加がなければ完全雇用を達成できない。前者の場合、非自発的失業はたやすく癒せる病気 であるが、逆に、一旦非自発的失業の発生をゆるすと重病になりがちである。後者の場合には、雇用は変化しにくいが、低いレベルで安定してしまいがちで、大 胆な治療がなくては中々治らない。
 
  In actual fact the marginal propensity to consume seems to lie somewhere between these two extremes, though much nearer to unity than to zero; with the result that we have, in a sense, the worst of both worlds, fluctuations in employment being considerable and, at the same time, the increment in investment required to produce full employment being too great to be easily handled. Unfortunately the fluctuations have been sufficient to prevent the nature of the malady from being obvious, whilst its severity is such that it cannot be remedied unless its nature is understood.
 
実際には限界消費性向はこの両極端の間のどこかに収まると思われる。ただし、ゼロよりは1の方に近いので、現実は両極端がもつ最悪の部分を併せ持ってい る。つまり、雇用の変動はかなり大きく、それと同時に、完全雇用をもたらすのに必要な投資の増加はたやすく扱えないほどに大きい。不幸なことに、病気(= 非自発的失業)はその本質を理解しなければ治療できないほど深刻なのに、雇用の変動が激しくて病気の本質は明らかにできないのだ。

  When full employment is reached, any attempt to increase investment still further will set up a tendency in money-prices to rise without limit, irrespective of the marginal propensity to consume; i.e. we shall have reached a state of true inflation.[4] Up to this point, however, rising prices will be associated with an increasing aggregate real income.

  完全雇用が達成された時には、さらに投資を増やす試みは、限界消費性向の動きとは別に、物価を際限なく上昇させる傾向をもたらすだろう。つまり、その時に は真性インフレーションの状態に達しているのである[4]。しかしながら、それまでは、物価の上昇は総実質所得の増加を伴うだろう。

III

We have been dealing so far with a net increment of investment. If, therefore, we wish to apply the above without qualification to the effect of (eg.) increased public works, we have to assume that there is no offset through decreased investment in other directions,- and also, of course, no associated change in the propensity of the community to consume. Mr. Kahn was mainly concerned in the article referred to above in considering what offsets we ought to take into account as likely to be important, and in suggesting quantitative estimates. For in an actual case there are several factors besides some specific increase of investment of a given kind which enter into the final result. If, for example, a Government employs 100,000 additional men on public works, and if the multiplier (as defined above) is 4, it is not safe to assume that aggregate employment will increase by 400,000. For the new policy may have adverse reactions(反作用) on investment in other directions.

第3節

我々はここまで投資の純増加を扱ってきた。したがって、もしこれまでの議論を例えば公共工事の増加の効果に対して無条件に当てはめたいのなら、他の分野へ の投資の減少による相殺効果がないと仮定しなければならない。さらにまた、それに伴って社会の消費性向に変化がないと仮定しなければならない。カーン氏は 上記の論文のなかで主にどんな相殺効果を考慮することが重要だと思われるかを検討して、量的な評価を示そうとした。というのは、実際のケースでは、投資の 増加以外にも最終的な結果に関わる幾つかの要素があるからである。例えば、もし政府が公共事業で10万人を追加雇用して、乗数(上で定義した)が4なら、 総雇用は40万人増えると考えるのは間違いである。というのは、新たな政策は他の分野の投資に逆作用をもたらすかもしれないからである。

  It would seem (following Mr. Kahn) that the following are likely in a modern community to be the factors which it is most important not to overlook (though the first two will not be fully intelligible until after Book IV. has been reached):

カーン氏によれば、現代社会においては以下の要素を見落とさないことが非常に大切である。もっとも最初の2つは第4巻に来るまでは充分理解できないかもしれない。

(i) The method of financing the policy and the increased working cash, required by the increased employment and the associated rise of prices, may have the effect of increasing the rate of interest and so retarding investment in other directions, unless the monetary authority takes steps to the contrary; whilst, at the same time, the increased cost of capital goods will reduce their marginal efficiency to the private investor, and this will require an actual fall in the rate of interest to offset it.

(一)雇用の増加とそれに伴う物価の上昇によって必要となる財政施策の方法と必要資金の追加は、金融当局が対抗策を取らない限り、利子率を上昇させて他の 分野への投資を遅らせる可能性がある。それと同時に、投資財の追加費用は、個人投資家の限界効率を減少させるだろう。それを防止するためには実際に利子率 が下がることが必要となる。

(ii) With the confused psychology which often prevails, the Government programme may, through its effect on “confidence”(=確信度), increase liquidity-preference or diminish the marginal efficiency of capital, which, again, may retard other investment unless measures are taken to offset it.

(ニ)混乱した心理状態が支配的な場合には、政府のプログラムは企業家の「確信度(=景気見通し)」(=初出)に対して悪影響を及ぼし、流動性選好(=初 出、貨幣需要量)を高めてしまうか、あるいは、資本の限界効率を低下させてしまう。防止策を施さないと今度はそれが他の投資を遅らせてしまう。

(iii) In an open system with foreign-trade relations, some part of the multiplier of the increased investment will accrue to the benefit of employment in foreign countries, since a proportion of the increased consumption will diminish our own country's favourable foreign balance; so that, if we consider only the effect on domestic employment as distinct from world employment, we must diminish the full figure of the multiplier. On the other hand our own country may recover a portion of this leakage through favourable repercussions due to the action of the multiplier in the foreign country in increasing its economic activity.

(三)海外貿易がある開放経済では、追加投資の乗数の一部は外国の雇用にとって有利に働く。なぜなら、追加消費の一部は自国の貿易収支の黒字を減らすよう に働くからである。そのため、もし世界の雇用ではなく国内の雇用だけを考えるとしたら、乗数の値を減額しなければならない。その一方で、外国における乗数 の働きがその国の経済活動を活性化することによって、国内での減額分を取り戻す可能性はある。

Furthermore, if we are considering changes of a substantial amount, we have to allow for a progressive change in the marginal propensity to consume, as the position of the margin is gradually shifted; and hence in the multiplier. The marginal propensity to consume is not constant for all levels of employment, and it is probable that there will be, as a rule, a tendency for it to diminish as employment increases; when real income increases, that is to say, the community will wish to consume a gradually diminishing proportion of it.

さらに、もしかなり大きな量の変化を考えるなら、限界消費性向とそれに伴う乗数が、限界位置の段階的移動に従って、漸進的に変化することを考慮に入れなけ ればならない。限界消費性向は全ての雇用レベルにおいて一定ではない。概して、おそらくは雇用が増えるにつれて限界消費性向は減少する傾向がある。すなわ ち、実質所得が増加するときは、社会がその所得を消費する割合は徐々に減少するのである。

There are also other factors, over and above the operation of the general rule just mentioned, which may operate to modify the marginal propensity to consume, and hence the multiplier; and these other factors seem likely, as a rule, to accentuate the tendency of the general rule rather than to offset it. For, in the first place, the increase of employment will tend, owing to the effect of diminishing-returns in the short period, to increase the proportion of aggregate income which accrues to the entrepreneurs, whose individual marginal propensity to consume is probably less than the average for the community as a whole.

 限界消費性向と乗数を変えるように働く可能性のある要素は、上記にあげた一般的なルールのほかにも色々ある。それは概して一般的なルールの効果をどちら かと言えば強めるように働くようである。というのは、第一に、雇用の増加は、短期における収穫逓減効果によって、総所得のうちの企業家に属する割合を増や す傾向がある。そして、企業家の限界消費性向は社会の平均的な消費性向よりも低いと思われるのである。
 
 In the second place, unemployment is likely to be associated with negative saving in certain quarters, private or public, because the unemployed may be living either on the savings of themselves and their friends or on public relief which is partly financed out of loans; with the result that re-employment will gradually diminish these particular acts of negative saving and reduce, therefore, the marginal propensity to consume more rapidly than would have occurred from an equal increase in the community's real income accruing in different circumstances.

  第二に、失業は一部で公私による負の貯蓄を発生させる。なぜなら、失業した人は自分か友人の貯蓄で生活するか、借入れ金から拠出された公的援助で生活する からである。再雇用はこのような負の貯蓄を徐々に減らして、限界消費性向を急速に減らして行く。それは違う状況で社会の実質所得が同じだけ増加した場合よ り急速である。
 
  In any case, the multiplier is likely to be greater for a small net increment of investment than for a large increment; so that, where substantial changes are in view, we must be guided by the average value of the multiplier based on the average marginal propensity to consume over the range in question.

いずれにせよ、純投資の増加が大きいよりも小さいほうが乗数は大きくなりがちであり、その結果、純投資の大きな変化を考えるときには、必要な範囲内での平均的な限界消費性向に基づく平均的な乗数を基準にすべきである。

Mr. Kahn has examined the probable quantitative result of such factors as these in certain hypothetical special cases. But, clearly, it is not possible to carry any generalisation very far. One can only say, for example, that a typical modern community would probably tend to consume not much less than 80 per cent. of any increment of real income, if it were a closed system with the consumption of the unemployed paid for by transfers from the consumption of other consumers, so that the multiplier after allowing for offsets would not be much less than 5.

カーン氏は特殊な仮定的ケースでこれらの要因がもたらす結果を大雑把な数量で検討した。しかし、明らかに、一般化をこれ以上進めることは不可能である。例 えば、もしある社会が閉鎖経済で失業者の消費が他の消費者の消費分からの移転によって賄われて、乗数が相殺分を考慮しても5に近い場合には、典型的な現代 社会は、実質所得の増加分の80%近くを消費に回す傾向があると言えるだけである。

 In a country, however, where foreign trade accounts for, say, 20 per cent. of consumption and where the unemployed receive out of loans or their equivalent up to, say, 50 per cent. of their normal consumption when in work, the multiplier may fall as low as 2 or 3 times the employment provided by a specific new investment. Thus a given fluctuation of investment will be associated with a much less violent fluctuation of employment in a country in which foreign trade plays a large part and unemployment relief is financed on a larger scale out of borrowing (as was the case, eg., in Great Britain in 1931), than in a country in which these factors are less important (as in the United States in 1932).[5]

 しかし、外国との貿易が消費の20%をしめていて、失業者は自分が働いていた時の普段の消費の50%までを借入れ金等からもらって生活している国では、 乗数は落ちこんで新投資がもたらす雇用を2倍か3倍にしか増やさない可能性がある。つまり、外国との貿易が多くを占めて失業対策が多くの場合借入れ金で賄 われている国(例えば1931年の英国)では、こうした要素が有力ではない国(例えば1932年の合衆国)よりも、投資の変動が雇用の急激な変動をもたら すことは遥かに少ない[5]。

  It is, however, to the general principle of the multiplier to which we have to look for an explanation of how fluctuations in the amount of investment, which are a comparatively small proportion of the national income, are capable of generating fluctuations in aggregate employment and income so much greater in amplitude than themselves.

 しかしながら、投資量の変動は、それが国民所得の比較的小さい割合でしかなくても、それ自身よりも大きな規模の変動を総雇用と総所得にもたらす可能性があるということの説明は、乗数の一般原理に求めるしかないのである。

IV

  The discussion has been carried on, so far, on the basis of a change in aggregate investment which has been foreseen sufficiently in advance for the consumption industries to advance pari passu with the capital-goods industries without more disturbance to the price of consumption-goods than is consequential,in conditions of decreasing returns, on an increase in the quantity which is produced.

第4節

  これまでの議論は総投資の変化があらかじめ充分予想がつくものとして進めてきた。この予想がつくと、消費財産業は資本財産業と足並みを揃えて進むし、消費財価格の変動も、収穫逓減の条件のもとで生産数が増えるために起きるより大きいことはない。

  In general, however, we have to take account of the case where the initiative comes from an increase in the output of the capital-goods industries which was not fully foreseen. It is obvious that an initiative of this description only produces its full effect on employment over a period of time. I have found, however, in discussion that this obvious fact often gives rise to some confusion between the logical theory of the multiplier, which holds good continuously, without time-lag, at all moments of time, and the consequences of an expansion in the capital-goods industries which take gradual effect, subject to time-lag and only after an interval.
 
  しかし、一般的に、資本財産業の産出物が予想外に増加したことから事態が変化するケースも考えておかねばならない。この種の変化が雇用に充分影響を与える には長い時間がかかるのは明らかである。しかしながら、この明らかな事実のせいで、乗数理論の論理と資本財産業の拡張の結果との間に混乱が起きていること を、私は議論の間に発見した。乗数理論は継続的にタイムラグなしにいつでも有効なのに、資本財産業の拡張の結果にはタイムラグがあり一定期間の後に徐々に 効果を表すからである。
 
The relationship between these two things can be cleared up by pointing out, firstly that an unforeseen, or imperfectly foreseen, expansion in the capital-goods industries does not have an instantaneous effect of equal amount on the aggregate of investment but causes a gradual increase of the latter; and, secondly, that it may cause a temporary departure of the marginal propensity to consume away from its normal value, followed, however, by a gradual return to it.

この両者の間の混乱を解決するには次のことを指摘すればよい。それは第一に、予想できないか不完全にしか予想できない資本財産業の拡張は、総投資に対して 同量の効果をすぐに発揮することはなく、後者を徐々に拡大させるということ。第二に、前者が限界消費性向を平常値から乖離させる可能性があり、その後、正 常値に徐々に戻るということである。

Thus an expansion in the capital-goods industries causes a series of increments in aggregate investment occurring in successive periods over an interval of time(一定の期間の後に), and a series of values of the marginal propensity to consume in these successive periods which differ both from what the values would have been if the expansion had been foreseen and from what they will be when the community has settled down to a new steady level of aggregate investment. But in every interval of time the theory of the multiplier holds good in the sense that the increment of aggregate demand is equal to the product(積) of the increment of aggregate investment and the multiplier as determined by the marginal propensity to consume.

つまり、資本財産業の拡張は、総投資の一連の増加を一定の期間の後に何期も連続してもたらし、この連続する期間に限界消費性向の一連の値をもたらす。それ らの値は、資本の拡張が予想されていた場合とも、いずれ社会が落ち着いて新たに安定した総投資レベルになった時とも、異なっている。しかし、総需要の増加 は総投資の増加に乗数(これは消費性向によった決まる)を掛けたものに等しいという意味において、乗数理論は全ての期間において有効である。

  The explanation of these two sets of facts can be seen most clearly by taking the extreme case where the expansion of employment in the capital-goods industries is so entirely unforeseen that in the first instance there is no increase whatever in the output of consumption-goods. In this event the efforts of those newly employed in the capital-goods industries to consume a proportion of their increased incomes will raise the prices of consumption-goods until a temporary equilibrium between demand and supply has been brought about partly by the high prices causing a postponement of consumption, partly by a redistribution of income in favour of the saving classes as an effect of the increased profits resulting from the higher prices, and partly by the higher prices causing a depletion of stocks(在庫の放出).

  この二つの事実が存在することを最も明確に説明するには、極端なケースを考えれば良い。つまり、資本財産業の雇用の拡張がまったく予想できないもので、最 初のうちは消費財産業の産出には何の増加も見られないというケースである。この場合、資本財産業に新たに雇用された人たちが自分たちの増えた所得の一部を 消費しようとすると、消費財の価格が上昇するだろう。それは、価格の上昇によって、消費が後回しになり、利潤が増えて貯蓄階級のために所得の再分配が行な れ、在庫が放出されて、需要と供給の一時的な均衡がもたらされるまで続くだろう。

So far as the balance is restored by a postponement of consumption there is a temporary reduction of the marginal propensity to consume, i.e. of the multiplier itself, and in so far as there is a depletion of stocks, aggregate investment increases for the time being by less than the increment of investment in the capital-goods industries, ― i.e. the thing to be multiplied does not increase by the full increment of investment in the capital-goods industries. As time goes on, however, the consumption-goods industries adjust themselves to the new demand, so that when the deferred consumption is enjoyed, the marginal propensity to consume rises temporarily above its normal level, to compensate for the extent to which it previously fell below it, and eventually returns to its normal level; whilst the restoration of stocks to their previous figure causes the increment of aggregate investment to be temporarily greater than the increment of investment in the capital-goods industries (the increment of working capital corresponding to the greater output also having temporarily the same effect).

需要と供給の均衡が、消費が後回しになることで回復される間は、限界消費性向の一時的な減退が生じるが、それはまさに乗数自体の減退である。また在庫が放 出されて枯渇している場合、総投資の増加は一時的に資本財産業への投資の増加より少ない。つまり、乗数で増える投資は資本財産業の増資を完全には反映しな いのである。しかし時が経つうちに、消費財産業は新たな需要に適応してきて、後回しにされた消費が実行されると、限界消費性向は一時的に標準レベルを上 回って、以前に標準以下に下落した分を埋め合わせて、そして最後に標準レベルに戻るのである。一方、在庫が以前の数字にまで戻ってくると、総投資の増加は 資本財産業の増資分よりも大きくなってくる(産出量の増加に対応する運転資本の増加も一時的に同じ効果を持つ)。

  The fact that an unforeseen change only exercises its full effect on employment over a period of time is important in certain contexts;- in particular it plays a part in the analysis of the trade cycle (on lines such as I followed in my Treatise on Money). But it does not in any way affect the significance of the theory of the multiplier as set forth in this chapter; nor render it inapplicable as an indicator of the total benefit to employment to be expected from an expansion in the capital-goods industries. Moreover, except in conditions where the consumption industries are already working almost at capacity so that an expansion of output requires an expansion of plant and not merely the more intensive employment of the existing plant, there is no reason to suppose that more than a brief interval of time need elapse before employment in the consumption industries is advancing pars passu with employment in the capital-goods industries with the multiplier operating near its normal figure.

  予期せぬ変化がその効果を完全に発揮するのはある期間の後であるという事実は、ある文脈で重要である。特にこの事実は景気循環を分析する際にある役割を果 たす(例えば私が『貨幣論』でたどった文脈)。しかし、この事実から、この章で提示された乗数理論の意味が変わることはないし、投資財産業の拡大から期待 できる雇用への全体的利益の指標として、乗数理論が使えないということにもならない。さらに、消費財産業が既にほぼフル操業状態で産出量の拡大には単に既 存のプラントの活用度を上げるだけではなくプラント自体の拡大が必要となっている場合以外には、乗数が正常値の近くにある場合には、消費財産業の雇用が資 本財産業の雇用と同時に発展するには長い時間の経過が必要であるとと考える理由はないのである。

V

  We have seen above that the greater the marginal propensity to consume, the greater the multiplier, and hence the greater the disturbance to employment corresponding to a given change in investment. This might seem to lead to the paradoxical conclusion that a poor community in which saving is a very small proportion of income will be more subject to violent fluctuations than a wealthy community where saving is a larger proportion of income and the multiplier consequently smaller.

第5節

  限界消費性向が大きくなると乗数も大きくなり、投資の変化に対応する雇用の変動も大きくなるということを我々は上記で見た。ここから我々は、貯蓄が所得の 非常に小さい部分を占めるような貧しい社会では、貯蓄が所得の大きな割合を占める(従って乗数も比較的小さい)豊かな社会よりは、激しい変動が起きやすい という逆説的な結論に至るかのように見える。

  This conclusion, however, would overlook the distinction between the effects of the marginal propensity to consume and those of the average propensity to consume. For whilst a high marginal propensity to consume involves a larger proportionate effect from given percentage change in investment, the absolute effect will, nevertheless, be small if the average propensity to consume is also high. This may be illustrated as follows by a numerical example.

  しかしこの結論は、限界消費性向と平均消費性向のもつ効果の違いを見逃した結果である。というのは、限界消費性向が高いと投資の割合の変化から相対的に大 きな効果が得られるが、もし同時に平均消費性向も高いと絶対的な効果は小さくなる。これは数字を伴う次の実例によって説明できる。

  Let us suppose that a community's propensity to consume is such that, so long as its real income does not exceed the output from employing 5,000,000 men on its existing capital equipment, it consumes the whole of its income; that of the output of the next 100,000 additional men employed it consumes 99 per cent., of the next 100,000 after that 98 per cent., of the third 100,000 97 per cent. and so on; and that 10,000,000 men employed represents full employment. It follows from this that, when 5,000,000 + n x 100,000 men are employed, the multiplier at the margin is 100/n, and n(n + 1)/2.(50 + n) per cent. of the national income is invested.

  社会の消費性向は次のようであるとする。まず、現存投資設備のもとで社会の実質所得が500万人の雇用から生まれる産出量を超えない間は、社会はその所得 の全てを消費する。そして、追加の10万人の雇用から生まれる産出量の99%を社会は消費し、次の10万人の追加から生まれる産出量の98%を社会は消費 し、三番目の10万人の産出量の97%等々となる。さらに、1千万人の雇用が完全雇用であるとすると、500万人+n×10万人が雇用された時(= (100ーn)%を消費する)、限界値の乗数は100/nであり、(=投資量はΣ10n/100=n(n+1)/20)国民所得のn(n+1)/2(50 +n)パーセントが投資されていることになる。

  Thus when 5,200,000 men are employed the multiplier is very large, namely 50, but investment is only a trifling proportion of current income, namely, 0.06 per cent.; with the result that if investment falls off by a large proportion, say about two-thirds, employment will only decline to 5,100,000, i.e. by about 2 per cent. On the other hand, when 9,000,000 men are employed, the marginal multiplier is comparatively small, namely 2.5, but investment is now a substantial proportion of current income, namely, 9 per cent.; with the result that if investment falls by two-thirds, employment will decline to 7,300,000, namely, by 19 per cent. In the limit where investment falls off to zero, employment will decline by about 4 per cent. in the former case, whereas in the latter case it will decline by 44 per cent.[6]

  つまり、520万人が雇用されているとき乗数は50と非常に大きいが、所得にしめる投資の割合はわずか0.06%にすぎないから、投資が例えば3分の2と いう大きな割合だけ減額しても、雇用は2%減って510万人になるだけである。それに対して、900万人が雇用されているときには、限界乗数は比較的小さ くて2.5となるが、投資は現行所得の9%とかなりの部分を占めているので、投資が3分の2だけ減ると、雇用は19%減って730万人になる。投資がゼロ にまで落ちる極端な場合では、前者は雇用が4%だけ下落するだけだが、後者は44%下落する[6]。

  In the above example, the poorer of the two communities under comparison is poorer by reason of under-employment. But the same reasoning applies by easy adaptation if the poverty is due to inferior skill, technique or equipment. Thus whilst the multiplier is larger in a poor community, the effect on employment of fluctuations in investment will be much greater in a wealthy community, assuming that in the latter current investment represents a much larger proportion of current output.[7]

  上記の例では、比較対象となる二つの社会のうちで貧しい方は雇用不足のために貧しいのであるが、貧しさが技術不足や設備不足のためであっても、簡単な修正 を加えれば同じ理屈が当てはまる。つまり、貧しい社会では乗数は大きいが、豊かな社会においては現行の投資が現行産出量の大きな部分を占める場合には、投 資の変動が雇用に与える影響は豊かな社会の方が大きいのである[7]。

  It is also obvious from the above that the employment of a given number of men on public works will (on the assumptions made) have a much larger effect on aggregate employment at a time when there is severe unemployment, than it will have later on when full employment is approached. In the above example, if, at a time when employment has fallen to 5,200,000, an additional 100,000 men are employed on public works, total employment will rise to 6,400,000. But if employment is already 9,000,000 when the additional 100,000 men are taken on for public works, total employment will only rise to 9,200,000. Thus public works even of doubtful utility may pay for themselves over and over again at a time of severe unemployment, if only from the diminished cost of relief expenditure, provided that we can assume that a smaller proportion of income is saved when unemployment is greater; but they may become a more doubtful proposition as a state of full employment is approached. Furthermore, if our assumption is correct that the marginal propensity to consume falls off steadily as we approach full employment, it follows that it will become more and more troublesome to secure a further given increase of employment by further increasing investment.

  以上から、公共事業の一定数の雇用は(上記の想定のもとで)深刻な失業の時の方が完全雇用が達成されそうな時よりも総雇用数に大きな影響を与えるのは明白 である。上記の例では、雇用が520万人まで落ち込んでいる時に、公共事業に追加の10万人の雇用があった場合には、総雇用数は640万人に跳ね上がる。 しかし、もし雇用がすでに900万人になっているなら公共事業による追加の10万人の雇用があっても、総雇用数は920万人に増えるだけである。つまり、 深刻な失業の時には所得から貯蓄される割合が減少すると仮定する場合には、深刻な失業の時には効果の疑わしい公共事業でも、失業手当の費用が減るという意 味だけからも、何度やっても効果がある。しかし、完全雇用が近づいている段階では、公共投資の効果はどんどん疑わしくなってくる。さらに、完全雇用に近づ くにつれて限界消費性向が徐々に低下するという我々の想定が正しければ、さらに投資を増やして一定の雇用数を増やすことはますます困難になってくる。

  It should not be difficult to compile a chart of the marginal propensity to consume at each stage of a trade cycle from the statistics (if they were available) of aggregate income and aggregate investment at successive dates. At present, however, our statistics are not accurate enough (or compiled sufficiently with this specific object in view) to allow us to infer more than highly approximate estimates. The best for the purpose, of which 1 am aware, are Mr. Kuznets' figures for the United States (already referred to in Chapter 8 above), though they are, nevertheless, very precarious. Taken in conjunction with estimates of national income these suggest, for what they are worth, both a lower figure and a more stable figure for the investment multiplier than I should have expected. If single years are taken in isolation, the results look rather wild. But if they are grouped in pairs, the multiplier seems to have been less than 3 and probably fairly stable in the neighbourhood of 2.5.
 
  総所得と総投資の連続した日々の統計(もしあればだが)から、景気循環の各ステージにおける限界消費性向のグラフを作ることは難しいことではないはずだ。 しかしながら、現状では、我々の統計は不正確で(あるいは特殊な目的のためだけに作られたものなので)極めて蓋然的な見積りしか推定することが出来ない。 この目的のために私が知っている最善のものは、合衆国についてのクズネッツ氏の数字(すでに第8章で見た)である。ただし、その数字は不確かなものであ る。国民所得の概算と並べてみると、その数字は現状では投資乗数にとっては私が期待する以上に低く安定した数字に見える。個別の年度を別に取り出したら、 結果はかなり不規則に見えるが、二つずつ並べてみると、乗数は3よりも小さく2.5の近辺でかなり安定しているように見えるのである。

This suggests a marginal propensity to consume not exceeding 60 to 70 per cent. ― a figure quite plausible for the boom, but surprisingly, and, in my judgment, improbably low for the slump. It is possible, however, that the extreme financial conservatism of corporate finance in the United States, even during the slump, may account for it. In other words, if, when investment is falling heavily through a failure to undertake repairs and replacements, financial provision is made, nevertheless, in respect of such wastage, the effect is to prevent the rise in the marginal propensity to consume which would have occurred otherwise. I suspect that this factor may have played a significant part in aggravating the degree of the recent slump in the United States. On the other hand, it is possible that the statistics somewhat overstate the decline in investment, which is alleged to have fallen off by more than 75 percent. in 1932 compared with 1929, whilst net “capital formation” declined by more than 95 per cent.; ― a moderate change in these estimates being capable of making a substantial difference to the multiplier.

この事実は限界消費性向が60%から70%を超えないということを示唆している。つまり、好景気の時には極めてありそうな数字なのだ。しかし不況の時には 驚くべきほどに、そして私の判断では、あり得ないほどに低い数字である。しかしながら、合衆国においては企業会計は財政面で極端な保守主義であることが、 その説明になるかもしれない。言い換えれば、もし修理や取替えが進まずに投資がひどく落ち込んでいる時に、それにも関わらず、その消耗に対する準備金が設 定される場合には、それがなければ上昇していたはずの限界消費性向を抑えることになってしまう。この要因は合衆国の最近の不況を悪化させるのに大きな役割 を果たしていると私は思っている。その一方で、統計は投資の下落をいくらか強調しすぎている可能性がある。1929年に比べて1932年には投資が75% も落ち込み、純資本形成は95%も落ち込んだとされているからである。これらの概算値はわずかに違うだけでも乗数に対して大きな変化をもたらす可能性があ る。

VI

  When involuntary unemployment exists, the marginal disutility of labour is necessarily less than the utility of the marginal product. Indeed it may be much less. For a man who has been long unemployed some measure of labour, instead of involving disutility, may have a positive utility. If this is accepted, the above reasoning shows how “wasteful” loan expenditure[8] may nevertheless enrich the community on balance. Pyramid-building, earthquakes, even wars may serve to increase wealth, if the education of our statesmen on the principles of the classical economics stands in the way of anything better.

第6節

  非自発的失業が存在するときは、労働力の限界不効用は必然的に限界生産物の効用を下回っている(=第3章2節、実質賃金の高止まり)。実際には、かなり下 回っている可能性がある。それどころか、失業が長い人にとっては、ある程度の労働は不効用(=苦痛)ではなくて、プラスの効用をもつ可能性がある。もしそ うなら、上記の理屈でいけば「不経済」な公債支出[8]でも、結果としては社会を富ませる可能性があるということになる。我々の政治家たちが古典経済学の 原理の教育を受けたせいでもっとましな手段をとれないのなら、ピラミッド建設や地震や戦争でさえも富を増やすのに役立つ可能性があるのである。

  It is curious how common sense, wriggling for an escape from absurd conclusions, has been apt to reach a preference for wholly “wasteful” forms of loan expenditure rather than for partly wasteful forms, which, because they are not wholly wasteful, tend to be judged on strict “business” principles. For example, unemployment relief financed by loans is more readily accepted than the financing of improvements at a charge below the current rate of interest; whilst the form of digging holes in the ground known as gold-mining, which not only adds nothing whatever to the real wealth of the world but involves the disutility of labour, is the most acceptable of all solutions.

  部分的に「不経済」な公債支出の方が完全に「不経済」ではないために厳密な「経営」原理に則っていると見られるにも関わらず、我々は常識にしたがって不合 理な結論を免れようとしながら、部分的に「不経済」な公債支出よりも完全に「不経済」な公債支出を選ぶ傾向があるのは奇妙なことである。例えば、公債から 拠出した失業手当の方が、雇用改善の低利融資よりも容易に受け入れられている。いやそれどころか、金採掘として知られる穴掘りは、世界の実際の富を一切増 やさないだけでなく労働の不効用を伴うにも関わらず、あらゆる解決策の中でもっとも好まれているのだ。

  If the Treasury were to fill old bottles with banknotes, bury them at suitable depths in disused coalmines<,>which are then filled up to the surface with town rubbish, and leave it to private enterprise on well-tried principles of laissez-faire to dig the notes up again (the right to do so being obtained, of course, by tendering for leases of the note-bearing territory), there need be no more unemployment and, with the help of the repercussions, the real income of the community, and its capital wealth also, would probably become a good deal greater than it actually is. It would, indeed, be more sensible to build houses and the like; but if there are political and practical difficulties in the way of this, the above would be better than nothing.

もし大蔵省が古い壺に紙幣を詰めて、廃坑になった炭鉱に適度な深さに埋めて、その上に町のゴミを満たして、その後で、多くの試練に耐えてきた自由放任主義 に基づいて、民間企業にその紙幣を掘り出させたなら(採掘権はもちろん紙幣を生む土地の賃貸権の入札によって入手できる)もはや失業は存在する必要がなく なる。また、その影響を受けて、社会の実質所得と資本資産もおそらく現実にあるよりもはるかに大きくなるだろう。もちろん、これより家を建てるなどのやり 方のほうが実際的であろう。しかし、政治的にも実際的にもこういう手段がとれないような困難な事情があるなら、何もしないよりは上記のことをする方がまし だろう。

  The analogy between this expedient and the goldmines of the real world is complete. At periods when gold is available at suitable depths experience shows that the real wealth of the world increases rapidly; and when but little of it is so available, our wealth suffers stagnation or decline. Thus gold-mines are of the greatest value and importance to civilisation. Just as wars have been the only form of large-scale loan expenditure which statesmen have thought justifiable, so gold-mining is the only pretext for digging holes in the ground which has recommended itself to bankers as sound finance; and each of these activities has played its part in progress―failing something better. To mention a detail, the tendency in slumps for the price of gold to rise in terms of labour and materials aids eventual recovery, because it increases the depth at which gold-digging pays and lowers the minimum grade of ore(=鉱石) which is payable.

  この方法と現実世界の金鉱は非常によく似ている。経験の教えるところでは、金が適当な深さで採掘できる間は世界の実際の富は急速に増加して(=理論の上記 と経験は逆)、金がなかなか採れなくなると世界の富は停滞か下り坂に入るのだ。つまり、金鉱は文明にとって最大の価値と重要性があるのだ。戦争が政治家た ちによって正当化されてきた唯一の大規模な公債支出であるのと同じく、金の採掘は銀行家たちに健全な融資策として歓迎されてきた唯一の穴掘りなのである。 それよりましな方法がない状況では、これらはどちらも人類の進歩に貢献してきたのである。もっと詳しく言うなら、不況のときに労働と原材料で測った金の価 格の上昇傾向が景気の回復を最終的に助けるのである。なぜなら、金の価格の上昇は、儲かる金採掘の深度と儲かる原材料の最低グレードを引き下げるからであ る。

  In addition to the probable effect of increased supplies of gold on the rate of interest, gold-mining is for two reasons a highly practical form of investment, if we are precluded from increasing employment by means which at the same time increase our stock of useful wealth. In the first place, owing to the gambling attractions which it offers it is carried on without too close a regard to the ruling rate of interest. In the second place the result, namely, the increased stock of gold, does not, as in other cases, have the effect of diminishing its marginal utility. Since the value of a house depends on its utility, every house which is built serves to diminish the prospective rents obtainable from further house-building and therefore lessens the attraction of further similar investment unless the rate of interest is falling part passu. But the fruits of gold-mining do not suffer from this disadvantage, and a check can only come through a rise of the wage-unit in terms of gold, which is not likely to occur unless and until employment is substantially better. Moreover, there is no subsequent reverse effect on account of provision for user and supplementary costs, as in the case of less durable forms of wealth.

金採掘は金の供給を増やして利子率に影響を与えるだけでなく、もし我々が効用ある富のストックを増加させると同時に雇用を増やす手段が見つからない場合に は、次の二つの理由で極めて実際的な投資形態である。その第一の理由は、金採掘はそれが提供するギャンブル的な魅力によって、支配的な利子率をあまり気に することなく実行できることであり、その第二の理由は、金採掘ではその結果金のストックが増えても他の場合と違って限界効用が減少しないことである。家の 価値はその効用に依存しているから、新たに家が建てられるごとに家を建てることから得られる将来の家賃は下がっていくので、利子率が同時に低下しない限 り、同じ投資を繰り返す魅力は減少する。ところが、金採掘から得られる金の蓄えにはこのような不都合はない。利益を妨げる要素があるとすれば、それは金で 測った単位賃金の上昇だけであるが、そんなことは雇用がかなり改善されない限り起こりそうもない。さらに、耐久性の低い資産の場合と違って、利用費用や補 足費用のための蓄えによって不利な作用が起きることもない。

Ancient Egypt was doubly fortunate, and doubtless owed to this its fabled wealth, in that it possessed two activities, namely, pyramid-building as well as the search for the precious metals, the fruits of which, since they could not serve the needs of man by being consumed, did not stale with abundance. The Middle Ages built cathedrals and sang dirges. Two pyramids, two masses for the dead, are twice as good as one; but not so two railways from London to York. Thus we are so sensible, have schooled ourselves to so close a semblance of prudent financiers, taking careful thought before we add to the “financial” burdens of posterity by building them houses to live in, that we have no such easy escape from the sufferings of unemployment. We have to accept them as an inevitable result of applying to the conduct of the State the maxims which are best calculated to “enrich” an individual by enabling him to pile up claims to enjoyment which he does not intend to exercise at any definite time.
古代エジプトはピラミッド建設と金鉱探索という二つの事業をもっていたために、二重の意味で幸福だったし、疑いもなくエジプトの伝説的な富はこの二つの事 業のおかげだった。これらの事業から得られたものは、消費されて人々の必要を満たすものではなかったので、いくら増えても陳腐化することがなかったからで ある。中世では大聖堂が建てられて大々的に葬儀が営まれた。二つのピラミッドと二つのミサは一つピラミッドと一つのミサと比べて二倍の価値がある。しか し、ロンドンからヨークに至る二本の線路は一つの線路の二倍の価値はない。つまり、現代の我々はあまりに分別があり、経済的な資本家そっくりに振る舞うこ とを身に着けているので、孫が住む家を建てることによって孫の経済的な負担を増やす前に、慎重な考慮を巡らせる。そのおかげで我々は失業という苦難からの 解決策をたやすく手に入れることが出来ないのである。我々は個人が「金持ちになる」ために周到に計算された行動指針を国家の行動に適応したために、その避 けがたい結果として失業という苦難を受け入れねばならないのである。その行動指針とは、自分がいつまでも実際に行使する気のない享楽の請求権(=流動性) を際限もなく積み上げることである。

Author's Footnotes

[1]. More precisely, if ee and e'e are the elasticities of employment in industry as a whole and in the investment industries respectively; and if N and N2 are the numbers of men employed in industry as a whole and in the investment industries, we have

ΔYw = Yw/(ee.N) .ΔN and ΔIw = Iw/(e'e.N2).ΔN2, so that

ΔN = (ee/e'e).(Iw/N2).(N/Yw).k.ΔN2, i.e., k' = (Iw/e'eN2).(eeN/Yw).k.

  If however, there is no reason to expect any material relevant difference in the shapes of the aggregate supply functions for industry as a whole and for the investment industries respectively, so that Iw/(ee'.N2) = Yw/(ee.N), then it follows that ΔYw/ΔN = ΔIw/ΔN2 and, therefore, that k = k'.


著者注

[1] より正確に言うと、eeとe'eを産業全体の雇用の弾力性(=20章に定義がある、賃金にたいする雇用の弾力性)、投資産業の雇用の弾力性とし、もしNとN2が産業全体の雇用者数、投資産業の雇用者数とすると、
ΔYw = (Yw/ee)×(ΔN/N)(←ee=ΔN/N×Yw/ΔYw)、
および
ΔIw = (Iw/e'e)×(ΔN2/N2)(←e'e=ΔN2/N2×Iw/ΔIw)、
したがって
ΔN = (ee/e'e)×(Iw/N2)×(N/Yw)×k×ΔN2(←k=ΔYw/ΔIw=(Yw/ee)×(ΔN/N)×(e'e/Iw)×(N2/ΔN2))、
つまり
k' = (Iw/(e'e×N2)).(ee×N/Yw)×k(←k'=ΔN/ΔN2、k' = (ee/e'e)×(Iw/N2)×(N/Yw)×k)、

しかし、もし産業全体の総供給関数の形と投資産業の総供給関数の形に大きな違いを予想する理由がなく、
Iw/(ee'×N2) = Yw/(ee×N)なら、ΔYw/ΔN = ΔIw/ΔN2 なので k = kとなる。'

[2]. Our quantities are measured throughout in terms of wage-units.

[2] 我々の量は単位賃金数で測ったものである。

[3]. Though in the more generalised case it is also a function of the physical conditions of production in the investment and consumption industries respectively.


[3] ただし、もっと一般的な場合には、乗数とは、投資産業と消費産業のそれぞれの生産の物理的条件の関数である。

[4]. Cf. Chapter 21, p. 303, below.


[4] 21章303頁参照

[5]. Cf., however, below, p. 128, for an American estimate.

[5] アメリカの数字については128頁参照。

[6]. Quantity of investment is measured, above, by the number of men employed in producing it. Thus if there are diminishing returns per unit of employment as employment increases, what is double the quantity of investment on the above scale will be less than double on a physical (if such a scale is available).

[6] 投資量はそれを生産するために雇用される人数で測られる。つまり、もし雇用が増えて雇用1単位あたりの収穫が低減するなら、雇用の尺度で測った投資の二倍は物理的尺度(そのような尺度があればだが)で測った投資の二倍より少ない

[7]. More generally, the ratio of the proportional change in total demand to the proportional change in investment

= (ΔY/Y)/(ΔI/I) = (ΔY/Y).{(Y - C)/(ΔY - ΔC)} = (1 - C/Y)/(1 - dC/dY)

As wealth increases dC/dY diminishes, but C/Y also diminishes. Thus the fraction increases or diminishes according as consumption increases or diminishes in a smaller or greater proportion than income.

[7] もっと一般的に言えば、総需要の変化率と投資の変化率の比率は

= (ΔY/Y)/(ΔI/I) = (ΔY/Y)×{(Y - C)/(ΔY - ΔC)} = (1 - C/Y)/(1 - dC/dY)
(←I=YーC))

富が増すに連れてdC/dYは減る。しかしC/Yも減る。つまりこの分数の値は消費が所得より大きい割合で増えたら増えるし、小さい割合で増えたら減る。また消費が所得より大きい割合で減ったら減るし、小さい割合で減ったら増える。

[8]. It is often convenient to use the term “loan expenditure“ to include both public investment financed by borrowing from individuals and also any other current public expenditure which is so financed. Strictly speaking, the latter should be reckoned as negative saving, but official action of this kind is not influenced by the same sort of psychological motives as those which govern private saving. Thus “loan expenditure” is a convenient expression for the net borrowings of public authorities on all accounts, whether on capital account or to meet a budgetary deficit. The one form of loan expenditure operates by increasing investment and the other by increasing the propensity to consume.

[8] 個人からの借入れで賄われた公共投資と当期の公共支出のことを「公債支出」という言葉で呼ぶのがしばしば便利である。厳密に言えば、後者はマイナス貯蓄と 考えるべきであるが、この種の公的活動は個人の貯蓄を左右する心理的動機には影響されない。したがって、「公債支出」という言葉は資本勘定、赤字予算など公共団体のあらゆる純借入れを表すのに好都合な表現なのである。公債支出でも前者のタイプは投資を増やすし、後者のタイプは消費性向を増やすのであ る。

Book IV The Inducement to Invest

第4巻 投資誘引

Chapter 11. The Marginal Efficiency of Capital

第11章 資本の限界効率

I

  WHEN a man buys an investment or capital-asset, he purchases the right to the series of prospective returns, which he expects to obtain from selling its output, after deducting the running expenses of obtaining that output, during the life of the asset. This series of annuities(年金) Q1, Q2, ... Qn it is convenient to call the prospective yield of the investment.

第1節

  人が投資物件や資本資産を購入するとき、彼はその資産が廃棄されるまでに生み出す産出物を売って得られる一連の予想収益(産出物を得るための費用は差し引 く)の権利を買うのである。この一連の毎年の利益(=年金)Q1, Q2, ... Qnを「投資の予想収益」と呼ぶのが便利である。

Over against the prospective yield of the investment we have the supply price of the capital-asset, meaning by this, not the market-price at which an asset of the type in question can actually be purchased in the market, but the price which would just induce a manufacturer newly to produce an additional unit of such assets, i.e. what is sometimes called its replacement cost.

この投資の予想収益の計算式の反対側に来るのが資本資産の「供給価格」である。供給価格とはそのタイプの資産が市場で実際に購入できる市場価格(=需要価 格)ではなく、業者が同じ機械を新たにもう一単位作る気になるような価格で、時には「再投資費用(=更新費用、更新原価)」と呼ばれるものである。

The relation between the prospective yield of a capital-asset and its supply price or replacement cost, i.e. the relation between the prospective yield of one more unit of that type of capital and the cost of producing that unit, furnishes us with the marginal efficiency of capital of that type.

ある資本資産の予想収益とその供給価格(あるいは再投資費用)の関係は、すなわち、そのタイプの追加資本一単位の予想収益とその追加資本一単位を作る価格との関係であり、それをそのタイプの「資本の限界効率」という。

More precisely, I define the marginal efficiency of capital as being equal to that rate of discount which would make the present value of the series of annuities given by the returns expected from the capital-asset during its life just equal to its supply price. This gives us the marginal efficiencies of particular types of capital-assets. The greatest of these marginal efficiencies can then be regarded as the marginal efficiency of capital in general.

もっと正確に言うなら、資本の限界効率とは、その資本資産が廃棄されるまでの予想収益からなる毎年の利益の合計の現在価値とその資本の供給価格とを等しく するような比率のことである。これが個々のタイプの資産の限界効率である。これらの限界効率うちの最大のものを資本全体の限界効率と見ることが出来る。

The reader should note that the marginal efficiency of capital is here defined in terms of the expectation of yield and of the current supply price of the capital-asset. It depends on the rate of return expected to be obtainable on money if it were invested in a newly produced asset; not on the historical result of what an investment has yielded on its original cost if we look back on its record after its life is over.

読者は、ここで資本の限界効率が資本資産(=機械)の予想収益とその現在の供給価格によって定義されていることに留意して欲しい。もしその投資が新品の資 産に対して行われたのなら、資本の限界効率とは予想収益に依存するものであり、その機械が廃棄された後で振り返ってみて実際に生み出された収益の結果とは 関係ない。

  If there is an increased investment in any given type of capital during any period of time, the marginal efficiency of that type of capital will diminish as the investment in it is increased, partly because the prospective yield will fall as the supply of that type of capital is increased, and partly because, as a rule, pressure on the facilities for producing that type of capital will cause its supply price to increase;
 
  ある期間内にあるタイプの資本(=機械)の投資が増えた場合には、その投資が増えた分だけそのタイプの資本の限界効率は減少するが、それは、そのタイプの 資本の供給が増えるに従って予想収益が減るからであり、またそのタイプの資本(=機械)を作る工場が忙しくなるとその資本(=機械)の供給価格が上がるか らである。

the second of these factors being usually the more important in producing equilibrium in the short run, but the longer the period in view the more does the first factor take its place. Thus for each type of capital we can build up a schedule, showing by how much investment in it will have to increase within the period, in order that its marginal efficiency should fall to any given figure. We can then aggregate these schedules for all the different types of capital, so as to provide a schedule relating the rate(仏訳では量、古い英語でも量) of aggregate investment to the corresponding marginal efficiency of capital in general which that rate of investment will establish. We shall call this the investment demand-schedule; or, alternatively, the schedule of the marginal efficiency of capital.

この内では二つ目の要素の方が均衡状態をもたらすために短期では重要な役割をもっているが、長期では一つ目の要素の方が重要な役割を果たす。そこで資本の タイプごとに、ある数字まで資本の限界効率が下がるにはその資本への投資がどれだけ増える必要があるかを示す一覧表(=グラフ)を作る事が出来る。そして その様々なタイプの全ての資本についての投資と限界効率の一覧表を集計して、総投資量とその投資量よって決まる資本全体の限界効率を結びつける一覧表を作 ることが出来る。これを我々は投資需要表、あるいは、資本の限界効率表と呼ぶことができる。


  Now it is obvious that the actual rate(額、量) of current investment will be pushed to the point where there is no longer any class of capital-asset of which the marginal efficiency exceeds the current rate of interest. In other words, the rate of investment will be pushed to the point on the investment demand-schedule where the marginal efficiency of capital in general is equal to the market rate of interest.[1]

  すると、現行利子率を超えるような限界効率(=予想収益率)をもつような資本がもう存在しないところまで、投資量が押し上げられるのは明らかである。言い 換えれば、投資量は投資需要表の上の資本の限界効率が市場利子率に一致するところまで押し上げられるのである(=内部収益率法)。[1]


  The same thing can also be expressed as follows. If Qr is the prospective yield from an asset at time r, and dr is the present value of £1 deferred(据え置いた) r years at the current rate of interest, ΣQrdr, is the demand price of the investment; and investment will be carried to the point where ΣQrdr becomes equal to the supply price of the investment as defined above. If, on the other hand, ΣQrdr, falls short of the supply price, there will be no current investment in the asset in question.

  同じ事は次のようにも言える(=割引現在価格法)。Qrをある資本資産のr年目の予想収益とし、drを現行利子率でのr年目の1ポンドの現在価値とする と、ΣQr×drがその投資資産の需要価格(=資本の需要価格)となる(=drは1/(1+利子率)、1/(1+利子率)の2乗、・・・r乗)。そして、 ΣQr×drが上で言った投資の供給価格(=資本の供給価格)に等しくなる点まで投資(=資本の追加)は行われる。逆に、ΣQr×drが供給価格を下回る とき、もう新たな投資は行われない。

  It follows that the inducement to invest depends partly on the investment demand-schedule and partly on the rate of interest. Only at the conclusion of Book IV. will it be possible to take a comprehensive view of the factors determining the rate of investment in their actual complexity. I would, however, ask the reader to note at once that neither the knowledge of an asset's prospective yield nor the knowledge of the marginal efficiency of the asset enables us to deduce either the rate of interest or the present value of the asset. We must ascertain the rate of interest from some other source, and only then can we value the asset by “capitalising”(英語はcapitalizing) its prospective yield.

  以上から、投資誘引は投資需要表にも依存するし利子率にも依存することになる。しかし、投資量を決める要素の複雑な全体像を知るためには、第4巻の最後ま で来ないと分からないだろう。ここで注意を喚起したいのは、ある資産の予想収益がわかっても資本の限界効率が分かっても、そこから利子率は分からないし資 産の現在価値も分からないということである。利子率は他のことから知るしかないのである。そして利子率が分かって初めて資産の予想収益を「資本に組み入れ る」ことで、資産の価値を知ることが出来るのだ。

II

  How is the above definition of the marginal efficiency of capital related to common usage? The Marginal Productivity or Yield or Efficiency or Utility of Capital are familiar terms which we have all frequently used. But it is not easy by searching the literature of economics to find a clear statement of what economists have usually intended by these terms.

第2節 一般的な用語と上記の考え方とのつながり

  上記の資本の限界効率の定義は一般的な用語とどうつながっているだろうか。「資本の限界生産力、限界収益、限界効率、限界効用」は馴染みの用語で誰もがよ く使ってきた。しかし、これらの用語を経済学者たちがどういう意味で使ってきたかを、彼らの書いたものから見つけることは容易なことではない。

There are at least three ambiguities to clear up. There is, to begin with, the ambiguity whether we are concerned with the increment of physical product per unit of time due to the employment of one more physical unit of capital, or with the increment of value due to the employment of one more value unit of capital. The former involves difficulties as to the definition of the physical unit of capital, which I believe to be both insoluble and unnecessary. It is, of course, possible to say that ten labourers will raise more wheat from a given area when they are in a position to make use of certain additional machines; but I know no means of reducing this to an intelligible arithmetical ratio which does not bring in values. Nevertheless many discussions of this subject seem to be mainly concerned with the physical productivity of capital in some sense, though(そして) the writers fail to make themselves clear.

明らかでない点が少なくとも三つある。それらを解決していこう。まず第一に、我々が扱っているのは、資本の物理的な一単位を追加して使用することに起因す る単位時間あたりの物理的な産出物の追加なのか、資本の価値一単位を追加して使用することに起因する価値の追加なのかが明確ではない。前者は資本の物理的 な単位の定義が困難であり、またこの困難の解決は不可能でありまた解決は不要であると私は信じている。もちろん、設備の追加的使用によって10人の労働者 が一定の区域から収穫する小麦の量が増えると言うことは出来る。しかし、このことを計算可能な比率に還元するには、価値を持ち込むしかないのである。それ にも関わらず、このテーマについての多くの議論は主に資本の物理的な生産力に関するものであるようである。そして、それらは理解可能なものになっていない のである。

Secondly, there is the question whether the marginal efficiency of capital is some absolute quantity or a ratio. The contexts in which it is used and the practice of treating it as being of the same dimension as the rate of interest seem to require that it should be a ratio. Yet it is not usually made clear what the two terms of the ratio are supposed to be.

第二に、資本の限界効率は絶対的な数量なのか、それとも比率なのかという問題がある。資本の限界効率が使われる文脈を見ても、それが利子率と同じ性質をも つものとして扱う習慣から見ても、資本の限界効率は比率であると考えるべきである。ところが、この比率が何と何の比率なのかは一般には明らかにされていな い。

Finally, there is the distinction, the neglect of which has been the main cause of confusion and misunderstanding, between the increment of value obtainable by using an additional quantity of capital in the existing situation, and the series of increments which it is expected to obtain over the whole life of the additional capital asset; ― i.e. the distinction between Q1 and the complete series Q1, Q2, ... Qr ... This involves the whole question of the place of expectation in economic theory. Most discussions of the marginal efficiency of capital seem to pay no attention to any member of the series except Q1. Yet this cannot be legitimate except in a static theory, for which all the Q's are equal. The ordinary theory of distribution, where it is assumed that capital is getting now its marginal productivity (in some sense or other), is only valid in a stationary state. The aggregate current return to capital has no direct relationship to its marginal efficiency; whilst its current return at the margin of production (i.e. the return to capital which enters into the supply price of output) is its marginal user cost, which also has no close connection with its marginal efficiency.

最後に、現状に対して資本を追加することで得られる追加の価値と、追加の資本が廃棄されるまでにその資本から得られると予想される一連の追加価値との区 別、即ち、単独のQ1と一連のQ1、Q2...Qr...の全体との区別がなされていないことから、混乱と誤解が生まれている。この区別は経済理論におけ る予想の位置付けという問題の全体を含んでいるのである。資本の限界効率に関するこれまでの議論は、この一連のQrではなくQ1にしか注目して来なかった と思われる。しかし、これがうまくいくのはすべてのQが同じ値である静的な理論だけである。資本は(ある意味での)限界生産力を今現在持っているとする一 般的な分配理論は、定常的な状況でのみ有効である。資本に対する現在の総収益は、資本の限界効率とは何の直接的関係もない。一方、資本の限界生産物におけ る現在の収益(つまり産出物の供給価格に含まれる資本の収益)は資本の限界使用費用であって、これもまた資本の限界効率とは何の関係もない。

There is, as I have said above, a remarkable lack of any clear account of the matter. At the same time I believe that the definition which I have given above is fairly close to what Marshall intended to mean by the term. The phrase which Marshall himself uses is “marginal net efficiency” of a factor of production; or, alternatively, the “marginal utility of capital”. The following is a summary of the most relevant passage which I can find in his Principles (6th ed. pp. 519-520). I have run together some non-consecutive sentences to convey the gist of what he says:

上で言ったように、この問題に対する明確な説明が著しく欠けているのである。それにも関わらず、私が上記で示した定義はマーシャルが意図しているものに非 常に近いと思う。マーシャルが使っている言葉は生産要素の「限界純効率」かあるいは「資本の限界効用」である。次に文章は彼の『経済原理』(第6版519 頁ー520頁)の中の関連する箇所の要約で、彼の言わんとする要点を伝えるためにばらばらの文章をつなげたものである。

“In a certain factory an extra £100 worth of machinery can be applied so as not to involve any other extra expense, and so as to add annually £3 worth to the net output of the factory after allowing for its own wear and tear. If the investors of capital push it into every occupation in which it seems likely to gain a high reward; and if, after this has been done and equilibrium has been found, it still pays and only just pays to employ this machinery, we can infer from this fact that the yearly rate of interest is 3 per cent. But illustrations of this kind merely indicate part of the action of the great causes which govern value. They cannot be made into a theory of interest, any more than into a theory of wages, without reasoning in a circle. ... Suppose that the rate of interest is 3 per cent. per annum on perfectly good security(証券); and that the hat-making trade absorbs a capital of one million pounds. This implies that the hat-making trade can turn the whole million pounds' worth of capital to so good account(利用する) that they would pay 3 per cent. per annum net for the use of it rather than go without any of it. There may be machinery which the trade would have refused to dispense with if the rate of interest had been 20 per cent. per annum. If the rate had been 10 per cent., more would have been used; if it had been 6 per cent., still more; if 4 per cent. still more; and finally the rate being 3 per cent., they use more still. When they have this amount, the marginal utility of the machinery i.e. the utility of that machinery which it is only just worth their while to employ, is measured by 3 per cent.”

「ある工場で100ポンドの価値のある機械を追加して、それ以上の追加費用なしに作動させると、機械の損耗を差し引いた後の純産出量が毎年3ポンド分ずつ 増えるものとする。もし投資家が高い収益を見込めるあらゆる業種に投資して、それによって均衡がもたらされた後に、この機械を使用してもなおぎりぎりで損 が出なかったとすると、この事実からその年の利子率は年3%だったと推測できる(=資本の限界効率が年利と同じだった)。しかし、この種の例が示している のは市場における価値を左右する大きな要因のごく一部である。この例から利子率の理論や賃金の理論を作ろうとしても循環論に陥るだけである。・・・完璧に 優良な債券の年利が3%であり、帽子会社に100万ポンドの投資が行われたとすると、それは帽子会社がその100万ポンドの資本(=機械)を放置すること なくちゃんと全部使えば年3%の純利益を出せるということである。たとえ利子率が年20%でも業者が使わないではいられない機械というものがある。それが 利子率10%ならもっと多くの機械が使われる。それが利子率6%ならもっと使われる。利子率4%ならもっとである。だから利子率3%ならさらに多くの機械 が使われるようになる。ということは、彼らがこれだけの機械をもっている時、この機械の限界効用、即ち使用してもぎりぎり損が出ない機械の効用は3%なの である」

  It is evident from the above that Marshall was well aware that we are involved in a circular argument if we try to determine along these lines what the rate of interest actually is.[2] In this passage he appears to accept the view set forth above, that the rate of interest determines the point to which new investment will be pushed, given the schedule of the marginal efficiency of capital. If the rate of interest is 3 per cent., this means that no one will pay £100 for a machine unless he hopes thereby to add £3 to his annual net output after allowing for costs and depreciation. But we shall see in Chapter 14 that in other passages Marshall was less cautious ― though still drawing back when his argument was leading him on to dubious ground.

ここからマーシャルはこの議論によって現実の利子率を決めようとすると循環論に陥るということを知っていたことは明らかである[2]。この文章において、 資本の限界効率表が与えられている時に新投資がどこまで押し進められるかは利子率によって決まるという上記の考え方を彼は受け入れていると思われる。つま り、利子率が3%ということは、ある機械に100ポンドを支払うのは、費用と減価償却を引いたその機械による純産出がそれによって毎年3ポンドずつ増える と予想できる場合だけだということを意味しているのである。しかし、第14章で見るように、マーシャルは別の箇所でもう少し大胆になっている。ただし議論 がはっきりしないところに行くと後退ぎみであるが。

Although he does not call it the “marginal efficiency of capital”, Professor Irving Fisher has given in his Theory of Interest (1930) a definition of what he calls “the rate of return over cost” which is identical with my definition. “The rate of return over cost”, he writes,[3] “is that rate which, employed in computing the present worth of all the costs and the present worth of all the returns, will make these two equal.” Professor Fisher explains that the extent of investment in any direction will depend on a comparison between the rate of return over cost and the rate of interest. To induce new investment “the rate of return over cost must exceed the rate of interest”.[4] “This new magnitude (or factor) in our study plays the central role on the investment opportunity side of interest theory.” [5] Thus Professor Fisher uses his “rate of return over cost” in the same sense and for precisely the same purpose as I employ “the marginal efficiency of capital”.

アーヴィング・フィッシャー教授も「資本の限界効率」という呼び方はしないが、「費用超過収益率」と呼ぶものの定義を『利子率の理論』(1930年)のな かで行なっているが、私の定義と同じである。「費用超過収益率は、総費用の現在価値と総収益の現在価値を計算するときに使われるもので、この2つのものを 同じ値にする比率である」と彼は書いている[3]。フィッシャー教授の説明では、どの分野であろうと投資のレベルは費用超過収益率と利子率との比較に依存 している。新投資を引き出すためには「費用超過収益率が利子率を超えなければならない」[4]。「我々の研究の中ではこの変数(あるいは要素)は投資機会 に関する利子理論において中心的な役割を果たしている」[5]。つまり、フィッシャー教授は「費用超過収益率」を「資本の限界効率」と同じ意味と同じ目的 で使っているのである。

III

  The most important confusion concerning the meaning and significance of the marginal efficiency of capital has ensued on the failure to see that it depends on the prospective yield of capital, and not merely on its current yield. This can be best illustrated by pointing out the effect on the marginal efficiency of capital of an expectation of changes in the prospective cost of production, whether these changes are expected to come from changes in labour cost, i.e. in the wage-unit, or from inventions and new technique. The output from equipment produced to-day will have to compete, in the course of its life, with the output from equipment produced subsequently, perhaps at a lower labour cost, perhaps by an improved technique, which is content with a lower price for its output and will be increased in quantity until the price of its output has fallen to the <lowest>[lower 仏訳より] figure with which it is content. Moreover, the entrepreneur's profit (in terms of money) from equipment, old or new, will be reduced, if all output comes to be produced more cheaply. In so far as such developments are foreseen as probable, or even as possible, the marginal efficiency of capital produced to-day is appropriately diminished.

第3節

  資本の限界効率の意味に関して最も重大な混乱は、それが予想収益に依存しているのであって、単に現在の収益に依存しているのではないということが理解でき ないことから来ている。生産費用の変化の予想が資本の限界効率に与える効果を指摘するのが、この違いを最もよく説明できるだろう。生産費用の変化は労働コ スト即ち単位賃金の変化から来たり技術革新から来ると予想されている。今日作られた設備からの産出物はその設備の寿命の間、恐らくもっと低い労働コストと もっと優れた技術で後日作られた設備から生まれる産出物と競争することになる。しかも、新しい設備は産出物の価格が安くても操業できるし、その設備は大量 に作られて産出物の価格が最低ラインにまで下がるのである。さらに、全ての産出物がもっと安く生産されるようになると、新旧の設備から得られる企業家の利 益(貨幣で測った)は減少する。そのような展開が充分予想される場合には、今日作られた資本設備の限界効率は減少するのである(=資本の限界効率のグラフ は右下がりになる)。

  This is the factor through which the expectation of changes in the value of money influences the volume of current output. The expectation of a fall in the value of money stimulates investment, and hence employment generally, because it raises the schedule of the marginal efficiency of capital, i.e. the investment demand-schedule; and the expectation of a rise in the value of money is depressing, because it lowers the schedule of the marginal efficiency of capital.

  この要因があるから、貨幣価値の変化(=物価)の予想が当期の産出量に影響するである。貨幣価値の下落(=物価の上昇)の予想は投資を刺激して雇用を増加 する。なぜなら、資本の限界効率表即ち投資需要表を上にシフトさせるからである。貨幣価値の上昇(=物価の下落)の予想は投資を抑制する。なぜなら、それ は資本の限界効率表を下にシフトさせるからである。

  This is the truth which lies behind Professor Irving Fisher's theory of what he originally called “Appreciation and Interest” ― the distinction between the money rate of interest and the real rate of interest where the latter is equal to the former after correction for changes in the value of money. It is difficult to make sense of this theory as stated, because it is not clear whether the change in the value of money is or is not assumed to be foreseen. There is no escape from the dilemma that, if it is not foreseen, there will be no effect on current affairs; whilst, if it is foreseen, the prices of existing goods will be forthwith(直ちに) so adjusted that the advantages of holding money and of holding goods are again equalised, and it will be too late for holders of money to gain or to suffer a change in the rate of interest which will offset the prospective change during the period of the loan in the value of the money lent. For the dilemma is not successfully escaped by Professor Pigou's expedient of supposing that the prospective change in the value of money is foreseen by one set of people but not foreseen by another.

  この事実こそはアーヴィン・フィッシャー教授の『価値の騰貴と利子』の理論の背後にあるものである。この理論は貨幣利子率と実質利子率の区別に関するもの で、後者は前者を貨幣価値変動分(=物価変動分)だけ修正した値である。彼の理論をそのままの形で理解するのは容易ではない。というのは、貨幣価値(=物 価)の変化は予想できると見なすのかどうかが明らかでないからである。もし貨幣価値の変化が予想できないなら、貨幣価値の将来の変化は現状に対して何の影 響力もない。しかし、もし予想できるなら、現在の財(=債券)の価格はその予測によって直ちに調整されて、貨幣を保有する利益と財を保有する利益は再びイ コールになってしまう。貨幣の保有者は利子率の変化によって損をしたり得をしたりする時間はない。利子率は、貸出し期間内に予想される貸出し貨幣の価値 (=物価)の変化を相殺するように変化するものだからである。誰もこのジレンマを逃れることは出来ない。ピグー教授のように貨幣価値の将来の変化は予測で きる人とできない人がいると考えても、それでこのジレンマをうまく逃れることは出来ないのである。

  The mistake lies in supposing that it is the rate of interest on which prospective changes in the value of money will directly react(反作用を及ぼす), instead of the marginal efficiency of a given stock of capital. The prices of existing assets will always adjust themselves to changes in expectation concerning the prospective value of money. The significance of such changes in expectation lies in their effect on the readiness to produce new assets through their reaction on the marginal efficiency of capital. The stimulating effect of the expectation of higher prices is due, not to its raising the rate of interest (that would be a paradoxical way of stimulating output ― in so far as the rate of interest rises, the stimulating effect is to that extent offset), but to its raising the marginal efficiency of a given stock of capital. If the rate of interest were to rise pari passu with the marginal efficiency of capital, there would be no stimulating effect from the expectation of rising prices. For the stimulus to output depends on the marginal efficiency of a given stock of capital rising relatively to the rate of interest. Indeed Professor Fisher's theory could be best re-written in terms of a “real rate of interest” defined as being the rate of interest which would have to rule, consequently on a change in the state of expectation as to the future value of money, in order that this change should have no effect on current output.[6]

  フィッシャー教授の間違いの原因は、貨幣価値(=物価)の将来の変化が資本の限界効率ではなく直接利子率に反作用を及ぼすと考えるところにある。現在の資 産の価格は常に将来の貨幣価値の予想の変化に合わせて変化する。そのような予想の変化の意義は、その変化が資本の限界効率に与える作用を通じて、新たな設 備を作ろうとする気持ちに影響をすることにある。物価上昇(=貨幣価値の下落)の予想が設備を作る気持ちを促すのは、その予想が利子率を引き上げる(利子 率の引上げは産出量を刺激する通常の方法ではない。利子率が上がると刺激効果はその分だけ相殺されるからである)からではなく、資本の限界効率を引き上げ るからである。もし利子率が資本の限界効率と足並みを揃えて上昇するなら、物価上昇の予想からの刺激的効果は全く生まれない。というのは、産出量に対する 刺激は、資本の限界効率が利子率より高いことから生れるからである。実際、フィッシャー教授の理論は、「実質利子率」を「将来の貨幣価値(=物価)の予想 の変化に応じて、この変化が当期の産出量に与える影響を相殺するように働く利子率」のことだと定義してから書き直すべきだろう[6]。

  It is worth noting that an expectation of a future fall in the rate of interest will have the effect of lowering the schedule of the marginal efficiency of capital; since it means that the output from equipment produced to-day will have to compete during part of its life with the output from equipment which is content with a lower return. This expectation will have no great depressing effect, since the expectations, which are held concerning the complex of rates of interest for various terms which will rule in the future, will be partially reflected in the complex of rates of interest which rule to-day. Nevertheless there may be some depressing effect, since the output from equipment produced to-day, which will emerge towards the end of the life of this equipment, may have to compete with the output of much younger equipment which is content with a lower return because of the lower rate of interest which rules for periods subsequent to the end of the life of equipment produced to-day.
 
  将来の利子率が下落することが予想されると、資本の限界効率表(=グラフ)は下にシフトする、ということは明記するに値する。というのは、これは今日作ら れた設備からの産出物はその設備の寿命の間もっと低い利益で操業できる設備の産出物と競争しなければならないことを意味するからである。将来の利子率の下 落の予想(=貨幣価値は上がる)には投資を抑制するそれほど大きな効果はない。というのは、様々な満期をもつ将来の利子率複合体に関する予想は今日の利子 率複合体に部分的に反映されるからである。それでも、利子率の下落の予想にはいくらか抑制効果はあるものだ。というのは、今日作られた設備からその寿命の 最後に生まれる産出物は、もっと新しい設備からの産出物と競争しなければならないが、新しい設備は今日作られた設備の寿命の最後の頃の低い利子率のおかげ で低い利益で操業できるからである。

  It is important to understand the dependence of the marginal efficiency of a given stock of capital on changes in expectation, because it is chiefly this dependence which renders the marginal efficiency of capital subject to the somewhat violent fluctuations which are the explanation of the Trade Cycle. In Chapter 22 below we shall show that the succession of Boom and Slump can be described and analysed in terms of the fluctuations of the marginal efficiency of capital relatively to the rate of interest.
 
  資本ストックの限界効率が予想の変化に依存することを理解するのは重要である。というのは、予想に依存するがゆえに資本の限界効率は大きな変動にさらされ ざるを得ないのであり、それが景気循環を説明しているのである。のちに第22章では、資本の限界効率の利子率に対する変動の見地から好景気と不景気の継起 を分析説明するつももりである。
 
IV

Two types of risk affect the volume of investment which have not commonly been distinguished, but which it is important to distinguish. The first is the entrepreneur's or borrower's risk(企業家、企業家側のリスク、借り入れ側のリスク)and arises out of doubts in his own mind as to the probability of his actually earning the prospective yield for which he hopes. If a man is venturing his own money, this is the only risk which is relevant.

第4節 リスクについて

一般には区別されていないけれども、投資に影響するリスクには2つのタイプがあって、これを区別することは重要である。一つ目のタイプのリスクは企業家の リスクつまり借り手のリスクである。これは彼が望む予想収益が実際に得られるかどうかの確実性に関する心理的な不安から来るリスクである。もしこれが自分 の金の投資なら(=内部金融)、リスクはこれで全てである。

But where a system of borrowing and lending exists, by which I mean the granting of loans with a margin(能力、余力、余裕) of real or personal security(担保), a second type of risk is relevant which we may call the lender's risk(貸し手側のリスク). This may be due either to moral hazard, i.e. voluntary default or other means of escape, possibly lawful, from the fulfilment of the obligation(債務の履行), or to the possible insufficiency of the margin of security(担保不足), i.e. involuntary default due to the disappointment of expectation. A third source of risk might be added, namely, a possible adverse change in the value of the monetary standard which renders a money-loan to this extent less secure than a real asset; though all or most of this should be already reflected, and therefore absorbed, in the price of durable real assets.

ところが、貸し借りの制度があって、物的担保や人的担保に対して融資する場合には、貸し手のリスクと呼ばれる二つ目のリスクが関係してくる。このリスクは 道義的リスクつまり意図的な破産や債務履行の合法的な回避によるものか、あるいは、担保不足による回収不能の可能性、つまり予想外れに起因する不本意な破 産によるものである。三つ目のリスクがあるとすれば、それは貨幣価値の不利な変化であろう。これは現物資産よりは金銭ローンを不安定にする。ただし、貨幣 価値の変化は耐久実物資産の価格に反映してそこに吸収されてしまう。

  Now the first type of risk is, in a sense, a real social cost(社会的費用), though susceptible to diminution by averaging (難平、リスクを平均化すること)as well as by an increased accuracy of foresight. The second, however, is a pure addition to the cost of investment which would not exist if the borrower and lender were the same person. Moreover, it involves in part a duplication of a proportion(一部) of the entrepreneur's risk, which is added twice to the pure rate of interest to give the minimum prospective yield which will induce the investment.
 
  ところで、一つ目のリスクはある意味で真の社会的費用である。この場合は、予測の精度を高めたりリスクを平均化したりすることでリスクの軽減化が可能であ る。それに対して、二つ目のリスクは投資費用への純粋な追加の費用で、これは借り手と貸し手が同じ人間なら発生しないものである。さらに、この二つ目のリ スクには企業家のリスクの一部が重複して含まれている。つまり、投資の誘引となる最小予想収益を決めるさいに、純粋利子率(=安全資産の利子率)に対して 企業家つまり借り手のリスクの一部が二度足し算されるのである。

 For if a venture is a risky one, the borrower will require a wider margin(上乗せ) between his expectation of yield and the rate of interest at which he will think it worth his while to borrow; whilst the very same reason will lead the lender to require a wider margin(利ざや、上乗せ) between what he charges and the pure rate of interest(純粋利子率) in order to induce him to lend (except where the borrower is so strong and wealthy that he is in a position to offer an exceptional margin of security(借り手の担保能力)). The hope of a very favourable outcome, which may balance the risk in the mind of the borrower, is not available to solace the lender.

というのは、もし事業がリスクのあるものなら(=借り手のリスク)、借り手は借金してもよいと考える利子率(=借入利子率=貸出利子率+借り手のリスクプ レミアム)と予想収益率との差が、事業のリスク分だけ大きくなることを求めるからであり、同じ理由で、貸し手側も彼が金を貸す気になるためには、自分が要 求する利子率(=貸出利子率=純粋利子率+貸し手のリスクプレミム)と純粋利子率との差がその事業のリスク分だけ大きくなることを求めるからである(もち ろん借り手が大金持ちで例外的に大きな担保能力がある場合は別である)。借り手側が自分の感じているリスクを相殺するような好結果を予測したところで、そ れは貸し手側にとっては何の慰めにもならないからである(=だから、貸し手にも借り手のリスクが影響する)。(『図解雑学ケインズ経済学』p124参照)

This duplication of allowance for a portion of the risk has not hitherto been emphasised, so far as I am aware; but it may be important in certain circumstances. During a boom the popular estimation of the magnitude of both these risks, both borrower's risk and lender's risk, is apt to become unusually and imprudently low.

リスクの一部がこのように重複して足算されていることは、私の知る限り、これまで強調されることはなかったが、一定の状況では重要であるかもしれない。好況時にはこれらの二つのリスクの大きさに対する一般の評価は無謀なまでに低くなりがちである。

V

The schedule of the marginal efficiency of capital is of fundamental importance because it is mainly through this factor (much more than through the rate of interest) that the expectation of the future influences the present. The mistake of regarding the marginal efficiency of capital primarily in terms of the current yield of capital equipment, which would be correct only in the static state where there is no changing future to influence the present, has had the result of breaking the theoretical link between to-day and to-morrow. Even the rate of interest is, virtually,[7] a current phenomenon; and if we reduce the marginal efficiency of capital to the same status, we cut ourselves off from taking any direct account of the influence of the future in our analysis of the existing equilibrium.

資本の限界効率表は非常に重要である。なぜなら、将来に対する予想が現在に影響するのは(利子率ではなく)主にこの資本の限界効率という要因だからであ る。資本の限界効率を現在の資本の収益率によって考えることは間違っている。それが正しいのは将来が現在に何の影響も及ぼさない静的な状態だけであって、 今日と明日を結ぶ理論的な糸を断ち切ってしまうことになる。利子率でさえもほとんど[7]現在の現象なのだ。もし資本の限界効率を利子率と同じ位置に置い てしまうならば、現在の均衡分析の際に未来がもっている影響を考慮することが出来なくなってしまう。

The fact that the assumptions of the static state often underlie present-day economic theory, imports into it a large element of unreality. But the introduction of the concepts of user cost and of the marginal efficiency of capital, as defined above, will have the effect, I think, of bringing it back to reality, whilst reducing to a minimum the necessary degree of adaptation.

静的な状態を想定することが現代の経済理論の基本になっていて、それが現代の経済理論を非現実的なものにしている。それに対して、私の考えでは、上記で説 明したような使用費用と資本の限界効率という概念を導入するという最低限の修正を加えることで、現代の経済理論を現実味を持ったものに戻すことが出来る。

  It is by reason of the existence of durable equipment that the economic future is linked to the present. It is, therefore, consonant with, and agreeable to, our broad principles of thought, that the expectation of the future should affect the present through the demand price for durable equipment.

耐久設備の存在することが経済の未来を現在に結びつけているのである。だから、将来に対する予想は耐久設備の需要価格を通じて現在に影響を及ぼすといっても、我々の考え方と概ね大差はない。

Author's Footnotes

[1]. For the sake of simplicity of statement I have slurred(見逃す) the point that we are dealing with complexes of rates of interest (利子率複合体)and discount corresponding to the different lengths of time which will elapse before the various prospective returns from the asset are realised. But it is not difficult to re-state the argument so as to cover this point.

[2]. But was he not wrong in supposing that the marginal productivity theory of wages is equally circular?

[3]. Op. cit. p. 168

[4]. Op. cit. p. 159.

[5]. Op. cit. p. 155.

[6]. Cf. Mr. Robertson's article on “Industrial Fluctuations and the Natural Rate of Interest”, Economic Journal, December 1934.

[7]. Not completely; for its value partly reflects the uncertainty of the future. Moreover, the relation between rates of interest for different terms depends on expectations.

著者注

[1] 叙述の単純化のために、ここで扱っているのが利子率と割引率の複合体であるという点は考慮に入れなかった。それらの利率は資産の様々な予想収益が 実現する迄に過ぎるべき時間の様々な長さに応じて異なっている。この点までの含めた議論にして書きなおすのは難しいことではない。

[2] しかし、マーシャルが賃金の限界生産性の理論も同様に循環理論になると考えているのは間違っているのではなかろうか。

[3] 前掲書168頁

[4] 前掲書159頁

[5] 前掲書155頁

[6] ロバートソン氏の論文『産業変動と自然利子率』(『エコノミック・ジャーナル』1934年12月号)参照。

[7] 完全にではない。というのは、利子率の値は未来の不確実性を一部反映しているからである。さらに、様々な期間の利子率どうしの関係も予想に依存している。 


Chapter 12. The State of Long-Term Expectation

第12章 長期予想

I

WE have seen in the previous chapter that the scale of investment depends on the relation between the rate of interest and the schedule of the marginal efficiency of capital corresponding to different scales of current investment, whilst the marginal efficiency of capital depends on the relation between the supply price of a capital-asset and its prospective yield. In this chapter we shall consider in more detail some of the factors which determine the prospective yield of an asset.

前の章で我々は投資の規模は利子率と資本の限界効率表(現在の投資の様々規模に対応する)との関係に依存し、資本の限界効率は資本資産の供給価格とその予想収益との関係に依存することを見た。この章では資産の予想収益を決定する要素の幾つかを詳しく検討していこう。

The considerations upon which expectations of prospective yields are based are partly existing facts which we can assume to be known more or less for certain, and partly future events which can only be forecasted with more or less confidence.

将来の収益を予想する際に材料とすべき検討対象は、一つには現在の確かな事実があり、一つには確信度を持って推測できる将来の出来事がある。

Amongst the first may be mentioned the existing stock of various types of capital-assets and of capital-assets in general and the strength of the existing consumers' demand for goods which require for their efficient production a relatively larger assistance from capital. Amongst the latter are future changes in the type and quantity of the stock of capital-assets and in the tastes of the consumer, the strength of effective demand from time to time during the life of the investment under consideration, and the changes in the wage-unit in terms of money which may occur during its life. We may sum up the state of psychological expectation which covers the latter as being the state of long-term expectation; ― as distinguished from the short-term expectation upon the basis of which a producer estimates what he will get for a product when it is finished if he decides to begin producing it to-day with the existing plant, which we examined in Chapter 5.

前者としては、様々なタイプの資本資産のストック、資本資産一般のストック、財に対する現在の消費者の需要の強さ、つまり効率的な生産のために資本のテコ 入れを必要としているほど需要があることがあげられる。後者としては、将来における資本資産ストックの量とタイプの変化、消費者の好みの変化、投資財が廃 棄されるまでの時々刻々の有効需要の強さ、その期間における貨幣で測った単位賃金の変化である。この後者に含まれる心理的な予想を長期予想と要約すること ができる。それに対して短期予想は第5章ですでに扱ったように、それをもとに生産者は現行プラントで今日生産を始めてそれが完成した時にその製品からいく ら利益が得られるかを推測するのである。

II

  It would be foolish, in forming our expectations, to attach great weight to matters which are very uncertain.[1] It is reasonable, therefore, to be guided to a considerable degree by the facts about which we feel somewhat confident, even though they may be less decisively relevant to the issue than other facts about which our knowledge is vague and scanty. For this reason the facts of the existing situation enter, in a sense disproportionately, into the formation of our long-term expectations; our usual practice being to take the existing situation and to project it into the future, modified only to the extent that we have more or less definite reasons for expecting a change.

  我々が物事の予想をするにあたって、全く不確かなことに重きをおくのは愚かなことである[1]。したがって、多くの場合ある程度確信の持てる事実を手引き にするのが合理的である。たとえその方が他のもっと不確かであやふやな事実よりも問題に対する決定的な関わり度が低いとしてもである。そのために、長期予 想を形成するときには現在の状況を示す事実が不釣り合いなほど入り込んでくるものである。我々の普通の習慣は現在の状況から出発してそれを将来に投影する のではあり、変化が予想できる確たる理由がある場合だけ、その習慣を修正するのである。

The state of long-term expectation, upon which our decisions are based, does not solely depend, therefore, on the most probable forecast(最も確実な予測) we can make. It also depends on the confidence(企業家の確信) with which we make this forecast ― on how highly we rate the likelihood of our best forecast turning out quite wrong. If we expect large changes but are very uncertain as to what precise form these changes will take, then our confidence will be weak.

したがって、我々の決断の根拠となる長期予想は単に最も確実な予測に依存するだけではない。長期予想は同時に、我々がこの予測を行う際の確信度(=景気見 通し、投資意欲)にも依存している。つまり、それは最も確実な予測が外れる可能性がどの程度あると考えるかにも依存しているのでる。大きな変化が予測され る時にその変化がどういう形をとるかについて確実でない時、我々の確信は弱まるのである。

The state of confidence(確信度), as they term it, is a matter to which practical men always pay the closest and most anxious attention. But economists have not analysed it carefully and have been content, as a rule, to discuss it in general terms. In particular it has not been made clear that its relevance to economic problems comes in through its important influence on the schedule of the marginal efficiency of capital. There are not two separate factors affecting the rate of investment, namely, the schedule of the marginal efficiency of capital and the state of confidence. The state of confidence is relevant because it is one of the major factors determining the former, which is the same thing as the investment demand-schedule.

実務家がいう確信度は彼らが常に最も注目しているものである。しかし、経済学者たちはそれを丁寧に分析することなく大雑把に語るだけで満足してきた。特に この確信の度合いは資本の限界効率表に大きな影響を与えて、それによって様々な経済問題に関わってくることは明らかにされて来なかった。資本の限界効率表 と確信度という二つの要素は、投資量に別々に影響するのではない。確信度は資本の限界効率表(これは投資需要表と同じものである)を決定する重要な要素の 一つであるがゆえに重要なのである。

There is, however, not much to be said about the state of confidence a priori. Our conclusions must mainly depend upon the actual observation of markets and business psychology. This is the reason why the ensuing digression is on a different level of abstraction from most of this book.

しかし、確信度について経験を離れて抽象的に言えることは多くない。我々の結論は現実の市場や経営心理の観察に基づかなければならない。そういうわけで、以下の脱線はこの本の多くの部分とは抽象レベルにおいて異なっている。

For convenience of exposition we shall assume in the following discussion of the state of confidence that there are no changes in the rate of interest; and we shall write, throughout the following sections, as if changes in the values of investments were solely due to changes in the expectation of their prospective yields and not at all to changes in the rate of interest at which these prospective yields are capitalised. The effect of changes in the rate of interest is, however, easily superimposed on the effect of changes in the state of confidence.

以下で行う確信度に関する議論では、話の便宜上利子率の変化はないものと仮定する。以下の節を通じて、投資の価値の変化はその予想収益の変化だけによって 起こり、その収益が資本化される時の利子率の変化には依らないものとする。しかし、利子率の変化の結果を確信度の変化の結果に追加するのは容易である。

III

  The outstanding fact is the extreme precariousness of the basis of knowledge on which our estimates of prospective yield have to be made. Our knowledge of the factors which will govern the yield of an investment some years hence is usually very slight and often negligible. If we speak frankly, we have to admit that our basis of knowledge for estimating the yield ten years hence of a railway, a copper mine, a textile factory, the goodwill of a patent medicine, an Atlantic liner, a building in the City of London amounts to little and sometimes to nothing; or even five years hence. In fact, those who seriously attempt to make any such estimate are often so much in the minority that their behaviour does not govern the market.

  特筆すべき事実は、未来の収益を評価する知識の基盤が極めてあやふやなことである。投資の数年後の利益を左右する要因について我々が知っていることは、普 通は非常に薄弱でとるに足らない事である。率直に言えば、鉄道にしろ銅山にしろ繊維工場にしろ特許薬の権利にしろ大西洋航路の定期船にしろロンドンのビル にしろ、今から10年後の収益を評価する知識の基盤はほぼゼロに等しいことを我々は認めなくてはならない。5年後でも同様である。実際、そのような評価を 真面目にしようとする人は非常に少数派なので、彼らの行動が市場を左右することはないのである。

  In former times, when enterprises were mainly owned by those who undertook them or by their friends and associates, investment depended on a sufficient supply of individuals of sanguine temperament and constructive impulses who embarked on business as a way of life, not really relying on a precise calculation of prospective profit. The affair was partly a lottery, though with the ultimate result largely governed by whether the abilities and character of the managers were above or below the average. Some would fail and some would succeed. But even after the event no one would know whether the average results in terms of the sums invested had exceeded, equalled or fallen short of the prevailing rate of interest; though, if we exclude the exploitation of natural resources and monopolies, it is probable that the actual average results of investments, even during periods of progress and prosperity, have disappointed the hopes which prompted them. Business men play a mixed game of skill and chance, the average results of which to the players are not known by those who take a hand. If human nature felt no temptation to take a chance, no satisfaction (profit apart) in constructing a factory, a railway, a mine or a farm, there might not be much investment merely as a result of cold calculation.
 
  昔のように企業が創業者とその仲間や友人たちのものだった時代には、投資は将来の利益の正確な計算にもとづいて行われるのではなく、人生の生き方として事 業に乗り出すような自信に満ちた前向きの人たちの行うことだった。もちろん、事業の結果は経営者の能力に大きく左右されたが、その一部は運任せだった。成 功する人もいれば失敗する人もいた。しかし、結果が出たあとで投資量と比べてそれが現行の利子率を上回っているか同じか下回っているかを誰も知ろうとはし なかった。もっとも、自然資源の乱用や独占を例外とするかぎり、投資の平均的な結果は、繁栄と進歩の時代においても、最初の期待を裏切るものだった。経営 者たちは技術と運の入り混じったゲームをしているのであって、このゲームの平均的な結果をゲームの参加者は知らないのである。もし人間の本姓が一か八かの 運試しに対して何の誘惑も感じず、工場や鉄道や鉱山や農場の建設に対して利益以外の喜びを全く感じないとしたら、冷静な計算の結果としての投資はそれほど 行われないかもしれない。

  Decisions to invest in private business of the old-fashioned type were, however, decisions largely irrevocable, not only for the community as a whole, but also for the individual. With the separation between ownership and management which prevails to-day and with the development of organised investment markets, a new factor of great importance has entered in, which sometimes facilitates investment but sometimes adds greatly to the instability of the system. In the absence of security markets, there is no object in frequently attempting to revalue an investment to which we are committed. But the Stock Exchange revalues many investments every day and the revaluations give a frequent opportunity to the individual (though not to the community as a whole) to revise his commitments. It is as though a farmer, having tapped his barometer after breakfast, could decide to remove his capital from the farming business between 10 and 11 in the morning and reconsider whether he should return to it later in the week.
 
  しかし、古いタイプの民間事業に対して投資する決断は、社会全体にとっても個人にとっても大抵は取り消しがきかなかった。今日のようにオーナーと経営者が 別になり、投資市場が組織されてからは、新たに非常に重要な要素が加わった。それはしばしば投資を容易にしたが、同時にしばしば制度をひどく不安定にし た。株式市場がなければ,自分の関わっている投資物件を頻繁に再評価をしようとしても無駄である。しかし、株式市場は多くの投資物件を日々再評価してお り、その再評価のおかげで個人(社会全体ではない)は自分の投資先を変更する機会を頻繁に与えられる。それはまるで農家が朝食後に晴雨計をチェックして、 農業ビジネスから自分の資本を午前10時と11時の間に引き上げることを決めて、その週の後半にまた農業ビジネスに戻るかどうか再考できるかのようであ る。
   
But the daily revaluations of the Stock Exchange, though they are primarily made to facilitate transfers of old investments between one individual and another, inevitably exert a decisive influence on the rate of current investment. For there is no sense in building up a new enterprise at a cost greater than that at which a similar existing enterprise can be purchased; whilst there is an inducement to spend on a new project what may seem an extravagant sum, if it can be floated off(市場で売りに出す) on the Stock Exchange at an immediate profit.[2] Thus certain classes of investment are governed by the average expectation of those who deal on the Stock Exchange as revealed in the price of shares, rather than by the genuine expectations of the professional entrepreneur.[3] How then are these highly significant daily, even hourly, revaluations of existing investments carried out in practice?

しかし、株式市場の毎日の再評価は主に古い投資を個人の間で移動しやすくするために行われているのであるが、それが現在の投資量に決定的な影響を及ぼすこ とは避けがたい。というのは、今ある企業を安い値段で買えるのに、同種の企業を新たに高い値段で作るのは馬鹿げているからである。その一方、もし新しいプ ロジェクトを株式市場で売りに出せばすぐに利益が得られるなら、そのプロジェクトに莫大な金を出資するインセンティブが生まれる[2]。つまり、ある種の 投資物件の部門は、プロの企業家の本心から立てた予想によってではなく、株価という形で表れる株式仲買人たちの平均的な思惑によって左右されるのである [3]。では今ある投資物件にとって重要な意味を持つ毎日の、いや毎時刻の再評価はどのようにして行われるのだろうか。

IV

  In practice we have tacitly agreed, as a rule, to fall back on what is, in truth, a convention. The essence of this convention ― though it does not, of course, work out quite so simply ― lies in assuming that the existing state of affairs will continue indefinitely, except in so far as we have specific reasons to expect a change. This does not mean that we really believe that the existing state of affairs will continue indefinitely. We know from extensive experience that this is most unlikely. The actual results of an investment over a long term of years very seldom agree with the initial expectation. Nor can we rationalize our behaviour by arguing that to a man in a state of ignorance errors in either direction are equally probable, so that there remains a mean actuarial expectation based on equi-probabilities.

  実際問題として、概して我々は「慣習」となっている事(=平均的人間が平均的にやっていること)に頼ることに暗黙のうちに一致している。この慣習の核心 は、もちろんそれほど単純に作用することはないが、変化が予測される明確な理由が存在しない場合には、現状がいつまでも続くと考えることである。これは我 々が現状がいつまでも続くと信じているということではない。そんなことはないのを我々は豊かな経験から知っている。長い年月の後の投資の結果が当初の予想 通りにはなることは滅多にないからである。かといって、無知の状態の置かれた人間にとってどの方向に間違うのも同じ位あり得ることだから、同じ確率に基づ いて統計的に平均を予測するしかないと言って、我々の行動(=慣習に従うこと)を正当化することは出来ない。

For it can easily be shown that the assumption of arithmetically equal probabilities based on a state of ignorance leads to absurdities. We are assuming, in effect, that the existing market valuation, however arrived at, is uniquely correct in relation to our existing knowledge of the facts which will influence the yield of the investment, and that it will only change in proportion to changes in this knowledge; though, philosophically speaking, it cannot be uniquely correct, since our existing knowledge does not provide a sufficient basis for a calculated mathematical expectation. In point of fact, all sorts of considerations enter into the market valuation which are in no way relevant to the prospective yield.

というのは、容易に示すことができるように、無知を元にした数理的確率が同じだと考えるのは馬鹿げたことだからである。実際、我々の想定では、現在の市場 の評価が正しいのは、それがどのようにして手に入れたものであっても、投資の利益に影響する事についての今の知識とつながっているからであり、市場の評価 が変わるのはこの知識に変化があるときだけである。もっとも、厳密に言うなら、数理的に計算された予測を我々の今の知識だけから出すのは不充分だから、そ れだけが正しいとは言えない。事実、予想収益とは何の関係もないあらゆる検討材料が市場の評価に関係しているのである。

Nevertheless the above conventional method of calculation will be compatible with a considerable measure of continuity and stability in our affairs, so long as we can rely on the maintenance of the convention.

それにも関わらず、この慣習(=平均的人間の平均的行動)の継続を当てに出来る場合には、平均を予測する上記の慣習的な計算方法は、我々の様々な事業のかなりのレベルの継続性と安定性との間に齟齬をきたすことはないだろう。

For if there exist organised investment markets and if we can rely on the maintenance of the convention, an investor can legitimately encourage himself with the idea that the only risk he runs is that of a genuine change in the news(情勢) over the near future, as to the likelihood of which he can attempt to form his own judgment, and which is unlikely to be very large. For, assuming that the convention holds good, it is only these changes which can affect the value of his investment, and he need not lose his sleep merely because he has not any notion what his investment will be worth ten years hence. Thus investment becomes reasonably “safe” for the individual investor over short periods, and hence over a succession of short periods however many, if he can fairly rely on there being no breakdown in the convention and on his therefore having an opportunity to revise his judgment and change his investment, before there has been time for much to happen. Investments which are “fixed” for the community are thus made “liquid” for the individual.

というのは、組織された投資市場が存在して、慣習の継続を当てに出来るなら、投資家は当然のことながら自分が冒す唯一のリスクは近い将来に関する情勢の明 らかな変化だけと考えて安心することが出来るからである。なぜなら、そのようなリスクの可能性については自分で判断できるし、それほど大きなリスクではな さそうだからである。というのは、慣習が続いているなら、そのような変化だけが投資の価値に影響があるし、10年後の自分の投資の価値がいくらになるか分 からないといってやきもきする必要はないからである。こうして、投資は短期においては個人投資家にとってかなり安全なものとなるのである。慣習の継続を当 てに出来て、自分の判断を変えることが出来て、色んな事が起きる前に投資先を変えられるなら、その後の短期の繰り返しの中でも同様に安全である。社会に とって固定している投資はこうして個人(=投資家)にとっては流動的なものになるのである。

  It has been, I am sure, on the basis of some such procedure as this that our leading investment markets have been developed. But it is not surprising that a convention, in an absolute view of things so arbitrary, should have its weak points. It is its precariousness which creates no small part of our contemporary problem of securing sufficient investment.

このように進み方で我々の主な投資市場は発展してきたと私は信じている。ところが、慣習はそれ自体としてみれば根拠が薄弱なものなので、それなりの弱点が あることは驚くべきことではない。その弱点とは不安定なことである。そして充分な投資を確保するという現代の我々の問題の多くの部分は、慣習の不安定さの ために生み出されているのである。

V

Some of the factors which accentuate this precariousness may be briefly mentioned.

慣習のこのうつろいやすさを加速する要因の幾つかをここで簡単にあげておこう。

(1) As a result of the gradual increase in the proportion of the equity in the community's aggregate capital investment which is owned by persons who do not manage and have no special knowledge of the circumstances, either actual or prospective, of the business in question, the element of real knowledge in the valuation of investments by those who own them or contemplate purchasing them has seriously declined.

(1)社会の総資本投資のうちで経営者でない人たちが所有する株式の割合が次第に増えているが、彼らには当該事業の現在ないし将来の状況に関する専門的知 識がないので、投資物件の所有者や所有を検討している人たちが投資物件を評価するときに、しっかりした知識が不足するようになっていること。

(2) Day-to-day fluctuations in the profits of existing investments, which are obviously of an ephemeral and non-significant character, tend to have an altogether excessive, and even an absurd, influence on the market. It is said, for example, that the shares of American companies which manufacture ice tend to sell at a higher price in summer when their profits are seasonally high than in winter when no one wants ice. The recurrence of a bank-holiday may raise the market valuation of the British railway system by several million pounds.

(2)現在の投資物件の利益の日々の変動は、明らかに一時的なものだったり無意味なものだったりしても、市場に対して過度の不合理な影響力をもつこと。例 えば、アメリカの製氷会社の株価は氷が売れない冬場よりも季節的な利益が多い夏場の方が高値で売れる傾向があると言われている。また、英国の鉄道の市場価 値は祝日がやってくるごとに起きる利用者増によってその都度上がるという。

(3) A conventional valuation which is established as the outcome of the mass psychology(群集心理) of a large number of ignorant individuals is liable to change violently as the result of a sudden fluctuation of opinion due to factors which do not really make much difference to the prospective yield; since there will be no strong roots of conviction to hold it steady. In abnormal times in particular, when the hypothesis of an indefinite continuance of the existing state of affairs is less plausible than usual even though there are no express grounds to anticipate a definite change, the market will be subject to waves of optimistic and pessimistic sentiment, which are unreasoning and yet in a sense legitimate where no solid basis exists for a reasonable calculation.

(3) 慣習的評価(=平均的人間による平均的評価)は大勢の無知な個人の群集心理の結果として定着しているものであるが、予想収益とあまりの関係のない ことから世論が突然変化して、その結果、慣習的評価は急激に変化する傾向があること。というのは、慣習的評価を不変に保つ信念となる強力な根っこは全くな いからである。特に混乱期には、明確な変化を予想する明らかな根拠が何もなくても、現状がいつまでも続くとする前提の信頼性が普通より低下しているので、 市場は楽観と悲観の波に翻弄されることになる。これは合理的なことではないが、合理的な計算の根拠が揺らいでいる場合にはある意味仕方のないことである。

(4) But there is one feature in particular which deserves our attention. It might have been supposed that competition between expert professionals, possessing judgment and knowledge beyond that of the average private investor, would correct the vagaries of the ignorant individual left to himself. It happens, however, that the energies and skill of the professional investor and speculator are mainly occupied otherwise. For most of these persons are, in fact, largely concerned, not with making superior long-term forecasts of the probable yield of an investment over its whole life, but with foreseeing changes in the conventional basis of valuation(慣習的な評価の変化を予想する) a short time ahead of the general public. They are concerned, not with what an investment is really worth to a man who buys it “for keeps”, but with what the market will value it at, under the influence of mass psychology, three months or a year hence. Moreover, this behaviour is not the outcome of a wrong-headed propensity. It is an inevitable result of an investment market organised along the lines described. For it is not sensible to pay 25 for an investment of which you believe the prospective yield to justify a value of 30, if you also believe that the market will value it at 20 three months hence.

(4)しかし特に注目に値する一つの特徴がある。プロの投資家たちは平均的な個人投資家よりも優れた知識と判断力をもっているので、彼らの競争によって無 知な個人投資家の気まぐれが正されると思わるかもしれない。しかし、実際にはプロの投資家と投機家たちのエネルギーはもっと別のことに費やされる。という のは、これらの人たちの主な関心は、実際には投資の寿命期間の後の収益についての高度な長期予想ではなくて、一般大衆の短期間の後の慣習的な評価の変化を 予測することなのだ。彼らの関心は、どの投資物件が本気で購入する価値があるかではなく、三ヶ月か一年後に大衆心理の影響で市場はそれをどう評価するかな のである。さらに、彼らのこの行動はひねくれた性格の結果ではない。それはすでに説明したように組織された投資市場の避けられない結果なのである。という のは、三〇の価値の予測収益が見込める投資物件でも、三ヶ月後に市場が二〇に評価することが分かっているなら、その物件にいま二五を出すのは賢明なことで はないからである。

  Thus the professional investor is forced to concern himself with the anticipation of impending changes, in the news(情勢) or in the atmosphere, of the kind by which experience shows that the mass psychology of the market is most influenced. This is the inevitable result of investment markets organised with a view to so-called “liquidity”. Of the maxims of orthodox finance none, surely, is more anti-social than the fetish of liquidity, the doctrine that it is a positive virtue on the part of investment institutions to concentrate their resources upon the holding of “liquid” securities. It forgets that there is no such thing as liquidity of investment for the community as a whole. The social object of skilled investment should be to defeat the dark forces of time and ignorance which envelop our future. The actual, private object of the most skilled investment to-day is “to beat the gun”, as the Americans so well express it, to outwit the crowd, and to pass the bad, or depreciating, half-crown to the other fellow.

  つまり、プロの投資家は市場の大衆心理が最も大きく影響を受ける類(たぐい)の差し迫った情勢や雰囲気の変化を予測することに注意を向けざるをえないので ある。これがいわゆる「流動性」を目指して組織された投資市場の避けがたい結果なのだ。正統派財政学の格言のうちでも「流動性の崇拝」ほど反社会的なもの はない。それは投資機関は自分の能力を流動的券の保持に集中することが積極的な美徳であるとする教えである。社会全体にとっては投資物件が流動的であるこ となどありえないことを、この格言は忘れている。熟練した投資家の社会的な使命は我々の将来を覆っている時間と無知の暗い力を打ち破ることでなければなら ない。今日の最も熟練した投資家の実際の個人的な目的はアメリカ人がうまく表現したように「人を出し抜く」ことであり、群衆の裏をかくことであり、質の悪 い価値の下がった半クラウン硬貨を他人に回すことなのである。

This battle of wits to anticipate the basis of conventional valuation(慣習的な評価を予測すること) a few months hence, rather than the prospective yield of an investment over a long term of years, does not even require gulls amongst the public to feed the maws of the professional; ― it can be played by professionals amongst themselves. Nor is it necessary that anyone should keep his simple faith in the conventional basis of valuation having any genuine long-term validity. For it is, so to speak, a game of Snap, of Old Maid, of Musical Chairs ― a pastime in which he is victor who says Snap neither too soon nor too late, who passes the Old Maid to his neighbour before the game is over, who secures a chair for himself when the music stops. These games can be played with zest and enjoyment, though all the players know that it is the Old Maid which is circulating, or that when the music stops some of the players will find themselves unseated.

長い年月の後の投資の収益を予想するのではなく、今から二,三ヶ月後の慣習的評価を予想するこの知恵の争いにおいては、専門家の胃袋を満たす素人のカモは 必要としないのだ。このゲームは専門家たちだけで争われるのである。また、慣習的評価に本心から見た長期の有効性があると素朴に信じる人がいる必要はな い。というのは、それは言わば、トランプのババ抜きや椅子取りゲームのようなものだからである。それはゲームが終わるまでにババを隣に回した人、音楽が止 まった時に椅子に座っていた人が勝つゲームである。ババが人の手を巡っていることはみんな知っているし、音楽が止まった時には誰かが椅子に座れないことを みんな知っているにもかからず、こうしたゲームは夢中になって楽しめるのである。

Or, to change the metaphor slightly, professional investment may be likened to those newspaper competitions in which the competitors have to pick out the six prettiest faces from a hundred photographs, the prize being awarded to the competitor whose choice most nearly corresponds to the average preferences of the competitors as a whole; so that each competitor has to pick, not those faces which he himself finds prettiest, but those which he thinks likeliest to catch the fancy of the other competitors, all of whom are looking at the problem from the same point of view. It is not a case of choosing those which, to the best of one's judgment, are really the prettiest, nor even those which average opinion genuinely thinks the prettiest. We have reached the third degree where we devote our intelligences to anticipating what average opinion expects the average opinion to be. And there are some, I believe, who practise the fourth, fifth and higher degrees.

あるいは比喩を変えるなら、プロの投資は参加者が6人の美人を100枚の写真から選ぶ新聞紙上の美人コンテストに似ている。賞金は自分の選んだ女性が競技 の参加者全員の平均的な選択に最も近い人に与えられる。そのために、参加者は自分が最も美しいと思う女性を選ぶのではなく、他の参加者たちに最も好かれそ うな女性を選ばなくてはならないので、全員が同じ観点から問題を見ることになる。それは自分の判断力の及ぶ限りで本当に最も美しい女性を選ぶのではなく、 平均的な意見が本心から誰を一番美しいと思っているかでもない。我々は平均的な意見は何を平均的な意見であると予想しているかを予想するために知性を注ぎ 込むという第三のレベルにたどり着いたのである。そして恐らく中には第四、第五いやもっと高度なレベルを実践している人もいるだろう。

  If the reader interjects that there must surely be large profits to be gained from the other players in the long run by a skilled individual who, unperturbed by the prevailing pastime, continues to purchase investments on the best genuine long-term expectations he can frame, he must be answered, first of all, that there are, indeed, such serious-minded individuals and that it makes a vast difference to an investment market whether or not they predominate in their influence over the game-players. But we must also add that there are several factors which jeopardise the predominance of such individuals in modern investment markets. Investment based on genuine long-term expectation is so difficult to-day as to be scarcely practicable. He who attempts it must surely lead much more laborious days and run greater risks than he who tries to guess better than the crowd how the crowd will behave; and, given equal intelligence, he may make more disastrous mistakes.

読者から次のような反論が出るかもしれない。世の中の投資ゲームに惑わされずに、自分が本心から立てた長期の最善の予想にもとづいて投資物件を購入し続け る熟練した投資家が結局は投資ゲームに興ずる人たちよりも多くの利益を手にするはずだと。それに対する答えは、まず第一に次のようになるに違いない。その ような真面目な投資家は確かに存在するし、彼らがゲーム感覚の投資家たちに対して優位を占めるかどうかで投資市場に大きな違いをもたらすはずだと。しか し、ここで付け加えなければならないのは、そのような個人の投資家が現代の投資市場で優位を占めることを危うくするような要因が沢山存在することである。 本心から立てた長期予想に基づく投資は今日では非常に難しいので殆ど実行不可能となっているのである。それを実行しようとする人は、群衆がどう振る舞うか を群集よりも上手く推測しようとする人よりも遥かに多くの苦労しながら遥かに大きなリスクを冒さなければならない。そして、同じ知性があるとしても、遥か に悲惨な失敗をする可能性がある。

There is no clear evidence from experience that the investment policy which is socially advantageous coincides with that which is most profitable. It needs more intelligence to defeat the forces of time and our ignorance of the future than to beat the gun. Moreover, life is not long enough; ― human nature desires quick results, there is a peculiar zest in making money quickly, and remoter gains are discounted by the average man at a very high rate. The game of professional investment is intolerably boring and over-exacting to anyone who is entirely exempt from the gambling instinct; whilst he who has it must pay to this propensity the appropriate toll. Furthermore, an investor who proposes to ignore near-term market fluctuations needs greater resources for safety and must not operate on so large a scale, if at all, with borrowed money ― a further reason for the higher return from the pastime to a given stock of intelligence and resources. Finally it is the long-term investor, he who most promotes the public interest, who will in practice come in for most criticism, wherever investment funds are managed by committees or boards or banks.[4] For it is in the essence of his behaviour that he should be eccentric, unconventional and rash in the eyes of average opinion. If he is successful, that will only confirm the general belief in his rashness; and if in the short run he is unsuccessful, which is very likely, he will not receive much mercy. Worldly wisdom teaches that it is better for reputation to fail conventionally than to succeed unconventionally.

経験から言って、社会に役立つ投資政策が最も利益の上がるものであるという明確な証拠はない。時間の力と未来に対する無知の力を打ち破るには、仲間を出し 抜くよりも多くの知性を必要とする。さらに、人生は充分に長くはない。人間の本姓は素早い結果を要求する。お金を急いでを作りたいという異常な熱意があ る。遠い先の利益は平均的な人間にとっては高い割合で割引かれた価値しかない。プロの投資ゲームはギャンブルの才能がない人にはまったく退屈で耐え難いも のであるが、ギャンブルの才能がある人はその性向のために相応の代価を支払う必要がある。そのうえ、投資家が市場の短期の変動を無視しようとするなら、安 全のためにもっと多くの資産が必要になるし、やるとしても借入金でそれほど大きな売買をすべきではない。これもまた、知性と資金が同じなら投資ゲームの方 が利益が大きいと言える理由である。最後に、投資資金が委員会や評議会や銀行で管理される場合は、最も社会のためになるはずの長期の投資家が最も批判を受 けることになる[4]。というのは、平均的な人から見て、投資家の行動の本質は、風変わりで型にはまらず向こう見ずであるとされるからである。投資家は仮 にもし成功しても、世間は投資家の向こう見ずを確認するだけであり、そして、もし短期間に損をしても(こちらの方が確率は高い)、あまり同情してはもらえ ない。世知の教えるところでは、突飛なことをして成功するより慣習に従って失敗するほうが評判はよいものだ。

(5) So far we have had chiefly in mind the state of confidence of the speculator or speculative investor himself and may have seemed to be tacitly assuming that, if he himself is satisfied with the prospects, he has unlimited command over money at the market rate of interest. This is, of course, not the case. Thus we must also take account of the other facet of the state of confidence, namely, the confidence of the lending institutions towards those who seek to borrow from them, sometimes described as the state of credit. A collapse in the price of equities, which has had disastrous reactions on the marginal efficiency of capital, may have been due to the weakening either of speculative confidence or of the state of credit. But whereas the weakening of either is enough to cause a collapse, recovery requires the revival of both. For whilst the weakening of credit is sufficient to bring about a collapse, its strengthening, though a necessary condition of recovery, is not a sufficient condition.

(5)これまで我々は投機家や投機的な投資家の確信度だけを考慮に入れて、投機家が自分の予想に自信があるなら市場の利子率でお金を無制限に調達できると 暗黙のうちに考えてきた。しかし、もちろん、事実はそうではない。つまり、我々は確信度の別の面、貸し手の機関が借り手に対して抱く確信、時に信用度と言 われるものも考慮に入れる必要がある。資本の限界効率に破壊的な作用をしてきた株価の暴落の原因は、この確信の度合いか信用の度合いのいずれかの低下だと 言えるのである。しかし、暴落を引き起こすのはどちらか一方の低下で充分だが、回復には両方の復活が必要である。信用の低下は暴落を引き起こすのに充分だ が、信用の復活は回復の必要条件ではあっても充分条件ではないからである。

VI

  These considerations should not lie beyond the purview of the economist. But they must be relegated to their right perspective. If I may be allowed to appropriate the term speculation for the activity of forecasting the psychology of the market, and the term enterprise for the activity of forecasting the prospective yield of assets over their whole life, it is by no means always the case that speculation predominates over enterprise. As the organisation of investment markets improves, the risk of the predominance of speculation does, however, increase. In one of the greatest investment markets in the world, namely, New York, the influence of speculation (in the above sense) is enormous. Even outside the field of finance, Americans are apt to be unduly interested in discovering what average opinion believes average opinion to be; and this national weakness finds its nemesis in the stock market. It is rare, one is told, for an American to invest, as many Englishmen still do, “for income”; and he will not readily purchase an investment except in the hope of capital appreciation. This is only another way of saying that, when he purchases an investment, the American is attaching his hopes, not so much to its prospective yield, as to a favourable change in the conventional basis of valuation, i.e. that he is, in the above sense, a speculator.

 経済学者はこうした検討材料を視野に入れておく必要があるが、その場合にも正しい観点から観察しなければならない。もし投機という言葉を市場心理を予測 する行動に充てて、企業活動という言葉を資産の寿命後の収益を予測する行動に充てることが許されるなら、投機は企業活動に対して優位に立つというのは決し ていつも真実ではない。しかしながら、投資市場の組織化が進んで、投機が優位を占める危険性が高くなっている。世界で最大の投資市場であるニューヨークで は、上記の意味における投機の影響力は絶大である。金融以外の分野でも、アメリカ人は「平均的な意見が平均的な意見を何であると思っているか」について異 常なほどに関心がある。そして、この国民的な弱点が株式市場で罰を受けているのである。今でも多くのイギリス人は「所得のために」投資をするが、同じよう に投資をするアメリカ人は珍しいと言われている。アメリカ人が進んで投資物件を購入するのは資本の騰貴が望めるときだけである。これは、アメリカ人が投資 物件を購入するとき期待するのはその予想収益ではなく慣習的な評価の好都合な変化であるということの単なる言い換えであり、アメリカ人は上記の意味での投 機家であるということの言い換えである。

Speculators may do no harm as bubbles on a steady stream of enterprise. But the position is serious when enterprise becomes the bubble on a whirlpool of speculation. When the capital development of a country becomes a by-product of the activities of a casino, the job is likely to be ill-done. The measure of success attained by Wall Street, regarded as an institution of which the proper social purpose is to direct new investment into the most profitable channels in terms of future yield, cannot be claimed as one of the outstanding triumphs of laissez-faire capitalism ― which is not surprising, if I am right in thinking that the best brains of Wall Street have been in fact directed towards a different object.

投機家が企業活動の安定した流れに浮かぶ泡沫であるなら何の害もないかもしれない。ところが、企業活動の方が投機の渦の中に浮かぶ泡沫になるなら事態は深 刻である。一国の資本の発展がカジノの副産物になるとき、その仕事はおそらく失敗する。ウォール・ストリートを将来の収益から見て最も有利な分野に新たな 投資を呼び込むことを本来の社会的目的とする機関であると見るならば、それが達成した成功は自由放任の資本主義の際立った勝利の一つであると主張すること は出来ない。ウォール・ストリートの最高の知能は実際には別の目的に向けられていると考えるのが間違いでないのなら、それは驚くべきことではない。

These tendencies are a scarcely avoidable outcome of our having successfully organised “liquid” investment markets. It is usually agreed that casinos should, in the public interest, be inaccessible and expensive. And perhaps the same is true of Stock Exchanges. That the sins of the London Stock Exchange are less than those of Wall Street may be due, not so much to differences in national character, as to the fact that to the average Englishman Throgmorton Street is, compared with Wall Street to the average American, inaccessible and very expensive. The jobber's “turn”, the high brokerage charges and the heavy transfer tax payable to the Exchequer, which attend dealings on the London Stock Exchange, sufficiently diminish the liquidity of the market (although the practice of fortnightly accounts operates the other way) to rule out a large proportion of the transactions characteristic of Wall Street.[5] The introduction of a substantial Government transfer tax on all transactions might prove the most serviceable reform available, with a view to mitigating the predominance of speculation over enterprise in the United States.

我々が「流動的」な投資市場を作り上げた以上は、こうした傾向はもはや避けられない。人々が普通一致した意見では、公衆の利益のためにはカジノは近づきに くく高くつく所にしなければならない。そしておそらく株式市場についても同じことが言える。ロンドンの株式市場がウォール・ストリートほど罪深くないの は、国民性の違いのせいではなく、平均的なイギリス人にとってスロッグモートン街は、平均的なアメリカ人にとってのウォール・ストリートよりも、近づきに くく高くつく所であるためである。ロンドンの株式市場では取引に必要な株式仲買人の手数料もブローカーの手数料も大蔵省へ払う譲渡税も高く、そのために市 場の流動性が弱められているので(ただし隔週決済の習慣は逆の方向に働いているが)、ウォール・ストリート[5]に特有の取引の多くが出来なくなってい る。アメリカ合衆国で投機が企業活動に対して優位に立っている現状を改善したければ、政府があらゆる取引にもっと大規模な譲渡税を導入すれば、最も効果的 な改革になるかもしれない。

The spectacle of modern investment markets has sometimes moved me towards the conclusion that to make the purchase of an investment permanent and indissoluble, like marriage, except by reason of death or other grave cause, might be a useful remedy for our contemporary evils. For this would force the investor to direct his mind to the long-term prospects and to those only. But a little consideration of this expedient brings us up against a dilemma, and shows us how the liquidity of investment markets often facilitates, though it sometimes impedes, the course of new investment. For the fact that each individual investor flatters himself that his commitment is “liquid” (though this cannot be true for all investors collectively) calms his nerves and makes him much more willing to run a risk. If individual purchases of investments were rendered illiquid, this might seriously impede new investment, so long as alternative ways in which to hold his savings are available to the individual. This is the dilemma. So long as it is open to the individual to employ his wealth in hoarding or lending money, the alternative of purchasing actual capital assets cannot be rendered sufficiently attractive (especially to the man who does not manage the capital assets and knows very little about them), except by organising markets wherein these assets can be easily realised for money.

近代の投資市場の有様を見ると、私は投資物件の購入を婚姻関係のように永久化して死亡など深刻な理由なしには解消できないようにするのが、現在の諸悪に対 する有効な治療策になるかもしれないと言いたくなる。というのは、こうすれば投資家は長期予想だけに目を向けざるを得なくなるからである。しかし、この方 法は少し考えるとすぐにジレンマに突き当たる。投資市場の流動性によって、新しい投資の進行が妨げられることが時にはあっても、多くの場合新たな投資の進 行がそれによって容易になっていることを、我々は認めざるをえないからである。というのは、個人の投資家は自分の投資物件が流動的であると思えると、安心 してもっと多くのリスクを冒す気になるからである。もし個人の投資物件の購入が流動的でなくなったら、貯蓄を保有する別の選択肢が利用可能な場合には、新 たな投資はひどく妨げられる可能性がある。これはジレンマである。自分の金を貯めこんでおくか貸し出すかを個人が選べる場合に、その金で現物の資本設備を 購入するという選択肢を魅力的にするには(特に投資家が資本設備を管理せずそれについても殆ど知識がない場合)、この資産を簡単に現金化できるような市場 を組織する以外にはないのである。

The only radical cure for the crises of confidence(確信度の危機=景気見通しの危機) which afflict the economic life of the modern world would be to allow the individual no choice between consuming his income and ordering the production of the specific capital-asset which, even though it be on precarious evidence, impresses him as the most promising investment available to him. It might be that, at times when he was more than usually assailed by doubts concerning the future, he would turn in his perplexity towards more consumption and less new investment. But that would avoid the disastrous, cumulative and far-reaching repercussions of its being open to him, when thus assailed by doubts, to spend his income neither on the one nor on the other.

近代社会の経済活動を悩ましている確信度の危機を根本から解決する唯一の方法は、個人が自分の所得を消費するか、不確かな証拠に基づいていても自分に最も 有望な投資だと思われる特定の資本資産の製造を注文する以外の選択肢をなくすことである。将来の不安に苛まれている時には、戸惑いの中で消費増やすして新 たな投資を減らすことだろう。しかし、不安に駆られて自分の所得をそのどちらにも使わないことが許される時に生ずる破壊的累積的で広範囲の影響をそれで回 避することができるのである。

Those who have emphasised the social dangers of the hoarding of money have, of course, had something similar to the above in mind. But they have overlooked the possibility that the phenomenon can occur without any change, or at least any commensurate change, in the hoarding of money.

金を消費にも投資にもまわさず家に貯めこむことの社会的な危険を強調する人たちは、もちろん、これと似たような事を考えていたのである。しかし、彼らはこ うした危険な現象が発生しても、貯めこんだ現金の量には何の変化も起きない、少なくともその現金量に比例した変化は起きないという可能性は見逃した。

VII

Even apart from the instability due to speculation, there is the instability due to the characteristic of human nature that a large proportion of our positive activities depend on spontaneous optimism rather than on a mathematical expectation, whether moral or hedonistic or economic. Most, probably, of our decisions to do something positive, the full consequences of which will be drawn out over many days to come, can only be taken as a result of animal spirits ― of a spontaneous urge to action rather than inaction, and not as the outcome of a weighted average of quantitative benefits multiplied by quantitative probabilities. Enterprise only pretends to itself to be mainly actuated by the statements in its own prospectus, however candid and sincere. Only a little more than an expedition to the South Pole, is it based on an exact calculation of benefits to come. Thus if the animal spirits are dimmed and the spontaneous optimism falters, leaving us to depend on nothing but a mathematical expectation, enterprise will fade and die; ― though fears of loss may have a basis no more reasonable than hopes of profit had before.

投機に起因する不安定さのほかに、人間の本姓の特徴に起因する不安定さがある。その特徴は、我々の積極的な行動のほとんどは数学的な予想に基づくものでは なく、道徳的あるいは快楽主義的あるいは経済的な、前向きの楽観主義に依存しているということである。おそらく我々が何か積極的なことをする決断の多く は、結果が出るまで長い年月がかかるような事であっても、それはアニマル・スピリット(血気)の結果であり、何もしないよりは何かしようとする前向きな衝 動の結果であって、加重平均した量的利益に量的確率をかけた結果ではないと考えてよい。企業の設立趣意書の中身がどれほど率直で本当らしくても、企業はそ れを主な動機にしているという振りをしているだけである。企業が将来の利益の正確な計算の上に立っているとしても、それは南極探検と同程度か、それより少 しましな程度でしかない。つまり、もしアニマル・スピリットが薄れて、前向きの楽観主義が揺らぐようなことになって、頼りになるのは数字上の予想だけに なったら、その企業は衰弱して死に絶える運命にある。もっとも、その段階での損失の恐怖に合理的理由はないのは、最初の利益の希望にも合理的な理由はない のと同じである。

  It is safe to say that enterprise which depends on hopes stretching into the future benefits the community as a whole. But individual initiative will only be adequate when reasonable calculation is supplemented and supported by animal spirits, so that the thought of ultimate loss which often overtakes pioneers, as experience undoubtedly tells us and them, is put aside as a healthy man puts aside the expectation of death.

未来に広がる希望(=長期の予想収益)に依存する企業は社会全体の為になることをしていると言って間違いはない。しかし、個々の創業心は、合理的な計算が アニマルスピリット(血気)によって補完され支えれたとき初めて十全なものとなるのである。その時、経験が疑いもなく教えるように、健康な人間がいつかは 死ぬ事を忘れてしまうように、最終的に損をするかもしれないという思い(=長期予想)は創業者の頭から吹き飛んでしまうのである。

This means, unfortunately, not only that slumps and depressions are exaggerated in degree, but that economic prosperity is excessively dependent on a political and social atmosphere which is congenial to the average business man. If the fear of a Labour Government or a New Deal depresses enterprise, this need not be the result either of a reasonable calculation or of a plot with political intent; ― it is the mere consequence of upsetting the delicate balance of spontaneous optimism. In estimating the prospects of investment, we must have regard, therefore, to the nerves and hysteria and even the digestions and reactions to the weather of those upon whose spontaneous activity it largely depends.

このことが意味するのは、不幸なことに、不景気と不況は実際よりも過度に強調されるということだけでなく、経済的な繁栄が平均的な実業家のもっている政治 的社会的な気分に過度に依存しているということでもある。もし労働党政権かニューディール政策への恐怖が企業を抑圧するなら、それは必ずしも合理的な計算 の結果でも、政治的意図をもった計画の結果であるとも言えない。むしろ、それは単なる前向きの楽観主義の微妙なバランスが壊された結果でしかないのだ。し たがって、投資の将来を予測するにあたっては、それが投資家の前向きの行動力に依存している以上は、我々は彼らの神経とヒステリーと消化の良さと天気への 反応にも留意しなければならないのである。


We should not conclude from this that everything depends on waves of irrational psychology. On the contrary, the state of long-term expectation is often steady, and, even when it is not, the other factors exert their compensating effects. We are merely reminding ourselves that human decisions affecting the future, whether personal or political or economic, cannot depend on strict mathematical expectation, since the basis for making such calculations does not exist; and that it is our innate urge to activity which makes the wheels go round, our rational selves choosing between the alternatives as best we are able, calculating where we can, but often falling back for our motive on whim or sentiment or chance.

ここからすべてが不合理な心理の波に依存していると我々は結論すべきではない。その反対に、長期予想はしばしば安定的であり、そうでない時でも、それを補 う効果を持つ要素は他にも沢山ある。我々は単に次のことを忘れないようにしているだけである。つまり、未来に影響を与える人間の決定は、個人的政治的経済 的を問わず、厳密な数学的予想に依拠しているわけではない。なぜなら、そのような計算をするための根拠は存在しないからである。また、世の中を動かしてい るのは行動への内的な衝動であって、我々の理性的な自己は可能な時には計算するが、多くの場合は気まぐれな感情と運委せの動機から、選択肢のうちで出来る だけ最良のものを選んでいるにすぎない。

VIII

  There are, moreover, certain important factors which somewhat mitigate in practice the effects of our ignorance of the future. Owing to the operation of compound interest(複利) combined with the likelihood of obsolescence with the passage of time, there are many individual investments of which the prospective yield is legitimately dominated by the returns of the comparatively near future. In the case of the most important class of very long-term investments, namely buildings, the risk can be frequently transferred from the investor to the occupier, or at least shared between them, by means of long-term contracts, the risk being outweighed in the mind of the occupier by the advantages of continuity and security of tenure. In the case of another important class of long-term investments, namely public utilities(公共事業), a substantial proportion of the prospective yield is practically guaranteed by monopoly privileges coupled with the right to charge such rates(料金) as will provide a certain stipulated margin(利潤).

さらに、我々の未来に対する無知の悪影響を実際上いくらか緩和してくれる重要な要素がいくつか存在する。複利計算と時間の経過で投資資産(=機械)が旧式 化する可能性のために、個々の投資物件の中には、当然のことながら比較的近い将来の利潤によって予想収益が決まってくるものが沢山ある。最も重要な長期投 資の分野であるビルディングの場合には、保有期間(=借家権)の継続性と安全性の利益の方がテナントの心理ではリスクより上回るので、長期の契約によって リスクはしばしば投資家からテナントに移転されことがあるし、少なくとも両者で分け合うことが可能である。もう一つ重要な長期投資の分野である公共事業の 場合には、規定の利潤を稼ぐ料金設定権など様々な独占的権利によって予想収益の非常に大きな部分が事実上保証されている。

Finally there is a growing class of investments entered upon by, or at the risk of, public authorities(公共機関), which are frankly influenced in making the investment by a general presumption of there being prospective social advantages from the investment, whatever its commercial yield may prove to be within a wide range, and without seeking to be satisfied that the mathematical expectation of the yield is at least equal to the current rate of interest, ― though the rate which the public authority has to pay may still play a decisive part in determining the scale of investment operations which it can afford.

最後に今増大しつつある投資分野が一つある。それは公共機関が自分のリスクで始めた投資である。この投資は将来の社会の為になるとする一般的な考え方が大 きな力をもっているので、その商業的利益はある広い範囲の中に収まっていればかまわないし、収益の数的な予想が少なくとも現行利子率に一致すべきだとする 条件を満たす必要もない。ただし、公共機関が行う投資活動の規模を決めるときには、それが支払う利子率は重要な役割を持つことはある。

Thus after giving full weight to the importance of the influence of short-period changes in the state of long-term expectation as distinct from changes in the rate of interest, we are still entitled to return to the latter as exercising, at any rate, in normal circumstances, a great, though not a decisive, influence on the rate of investment. Only experience, however, can show how far management of the rate of interest is capable of continuously stimulating the appropriate volume of investment.

以上において利子率の変化とは別に長期予想の短期の変化が投資に対してもたらす影響の大きさは充分に説明したので、今や我々はやはり利子率が、少なくとも 普通の状況では、投資量に対して決定的ではなくても重要な役割を果たすという話に戻ってもよいだろう。しかしながら、利子率を管理することによって適当な 投資量を継続的に刺激することがどこまで出来るのかは経験からしかわからない。

For my own part I am now somewhat sceptical of the success of a merely monetary policy(通貨政策、金融施策) directed towards influencing the rate of interest. I expect to see the State, which is in a position to calculate the marginal efficiency of capital-goods on long views and on the basis of the general social advantage, taking an ever greater responsibility for directly organising investment; since it seems likely that the fluctuations in the market estimation of the marginal efficiency of different types of capital, calculated on the principles I have described above, will be too great to be offset by any practicable changes in the rate of interest.

私の考えでは、利子率に影響を与える目的で行われる単なる通貨政策がうまくいくかどうかは疑わしいと思っている。長期的な視点で一般的な社会福祉のために 資本財の限界効率を計算できる国家が、大きな責任をもって投資の組織に直接乗り出すようになることを、私は期待している。というのは、様々なタイプの資本 の限界効率は市場の評価(私が上記で示した原理に従って計算された)の変動があまりに大きく、利子率の実際的な変化によって緩和できないからである。


Author's Footnotes

[1]. By “very uncertain' I do not mean the same thing as “improbable”. Cf. my Treatise on Probability, chap. 6, on “The Weight of Arguments”.

[2]. In my Treatise on Money (vol. ii. p. 195) I pointed out that when a company's shares are quoted very high so that it can raise more capital by issuing more shares on favourable terms, this has the same effect as if it could borrow at a low rate of interest. I should now describe this by saying that a high quotation for existing equities involves an increase in the marginal efficiency of the corresponding type of capital and therefore has the same effect (since investment depends on a comparison between the marginal efficiency of capital and the rate of interest) as a fall in the rate of interest.

[3]. This does not apply, of course, to classes of enterprise which are not readily marketable or to which no negotiable instrument(換金できる証券) closely corresponds. The categories falling within this exception were formerly extensive. But measured as a proportion of the total value of new investment they are rapidly declining in importance.

[4]. The practice, usually considered prudent, by which an investment trust or an insurance office frequently calculates not only the income from its investment portfolio but also its capital valuation in the market, may also tend to direct too much attention to short-term fluctuations in the latter.

[5]. It is said that, when Wall Street is active, at least a half of the purchases or sales of investments are entered upon with an intention on the part of the speculator to reverse them the same day. This is often true of the commodity exchanges also.

著者注

[1] 「非常に不確か」という言葉で私が意味するのは「ありそうにない」という言葉と同じではない。私の『確率論』第6章「推論の重みについて」参照。

[2] 自著『貨幣論』(第二巻195頁)で私は次の指摘をした。ある企業の株式に高値がついて好条件でさらに多くの株式を発行することでより多くの資本 を調達できるとき、このことは低利子率で借入れ出来るのと同じ事だと。今なら次のように言う。既存株式に高値が付くことはその株式に対応する資本の限界効 率が上がっていることを意味し、(投資は資本の限界効率と利子率を比較して行われるから)利子率の低下と同じ効果があると。

[3] 容易に市場化できない企業や流通証券がない企業にはこれは当てはまらない。この例外に属する部門は昔はかなり多かった。しかし、新投資の全価値のある部分として測ったとき、それらの重要性は急速に低下している。

[4] 投資信託や保険会社がしばしば投資のポートフォリオ(=複数の株式にリスクを分散して資産運用すること)からの所得だけでなく資本の市場価値も計算する際の賢明なやり方によれば、彼らは後者の短期の変動にあまりにも注目し過ぎる傾向がある。

[5] ウォール・ストリートが活況の時には、投資物件の売買の少なくとも半分は投機家がその日の内に反対売買する積りで行われると言われている。商品取引についてもしばしば同じ事が言える。


Chapter 13. The General Theory of the Rate of Interest

第13章 利子率の一般理論

I

  WE have shown in Chapter 11 that, whilst there are forces(=上ではfactors) causing the rate of investment to rise or fall so as to keep the marginal efficiency of capital equal to the rate of interest, yet the marginal efficiency of capital is, in itself, a different thing from the ruling rate of interest. The schedule of the marginal efficiency of capital may be said to govern the terms on which loanable funds are demanded for the purpose of new investment; whilst the rate of interest governs the terms on which funds are being currently supplied. To complete our theory, therefore, we need to know what determines the rate of interest.

第1節

  11章において我々は資本の限界効率が利子率と等しくなるように投資量を上下させる要素が存在するが(=内部収益率法)、資本の限界効率それ自体は支配的 な利子率(=市場利子率)とは別物であることを明らかにした(=第5節)。資本の限界効率表は、新たな投資のために借り入れる資金需要が起きる条件を決め るものであり、それに対して、利子率は現在における資金供給の条件を決めるものであると言っていい。したがって、我々の理論を完成するためには、利子率を 決めるものが何であるかを知る必要がある。

  In Chapter 14 and its Appendix we shall consider the answers to this question which have been given hitherto. Broadly speaking, we shall find that they make the rate of interest to depend on the interaction of the schedule of the marginal efficiency of capital with the psychological propensity to save. But the notion that the rate of interest is the balancing factor which brings the demand for saving in the shape of new investment forthcoming at a given rate of interest into equality with the supply of saving which results at that rate of interest from the community's psychological propensity to save, breaks down as soon as we perceive that it is impossible to deduce the rate of interest merely from a knowledge of these two factors.

What, then, is our own answer to this question?

  第14章とその付録で我々はこの問題に対して現在まで提示されている答えを検討する。大雑把に言って、利子率は資本の限界効率表と心理的な貯蓄性向の相互 作用によって決まるとされていることを我々は見出すだろう。しかしながら、利子率は貯蓄需要と貯蓄供給を一致される均衡要因であるとする考え方、つまり、 ある利子率で新投資として出てくる貯蓄需要と、その利子率で社会の心理的貯蓄性向から出てくる貯蓄供給を一致させる均衡要因であるとする考え方は、この二 つの要素(=投資と貯蓄)が分かっても利子率を導き出せないことが分かるやいなや崩壊するのである。

では、この問題に対する我々の答えは何だろうか?

II

  The psychological time-preferences of an individual require two distinct sets of decisions to carry them out completely. The first is concerned with that aspect of time-preference which I have called the propensity to consume, which, operating under the influence of the various motives set forth in Book III, determines for each individual how much of his income he will consume and how much he will reserve in some form of command over future consumption.
 
  個人の心理的な時間選好(=将来の消費よりも現在の消費を優先する傾向)を実行するには二つの異なる決定をする必要がある。その一つは時間選好のうちで消 費性向と私が呼ぶものに関する決定である。消費性向とは、第3巻に示した様々な動機から、個々の人間が自分の所得の内のいくらを消費して、いくらを将来の 消費に対する権利として何らかの形で保有するかを決めるものである。

  But this decision having been made, there is a further decision which awaits him, namely, in what form he will hold the command over future consumption which he has reserved, whether out of his current income or from previous savings. Does he want to hold it in the form of immediate, liquid command (i.e. in money or its equivalent)? Or is he prepared to part with immediate command for a specified or indefinite period, leaving it to future market conditions to determine on what terms he can, if necessary, convert deferred command over specific goods into immediate command over goods in general? In other words, what is the degree of his liquidity-preference ― where an individual's liquidity-preference is given by a schedule of the amounts of his resources, valued in terms of money or of wage-units, which he will wish to retain in the form of money in different sets of circumstances?

 しかし、この決定をしてからさらにもう一つしなければならない決定がある。それは当期の所得にしろ以前の貯蓄にしろ、その内から将来の消費に対する権利 をどのような形で保有するかという問題である。その権利を直接的な流動性のある形(貨幣かそれに相当するもの)で保つか、それとも、特定の期間だけあるい は期間を設けずにその直接的権利を手放す(=債権の購入)ことにするかという問題である。後者の場合には、特定の財に対する猶予された権利を、普遍的な財 に対する直接的権利に変換する条件の決定を、将来の市場の状況に委ねることになる。別の言葉で言えば、彼の流動性選好はどの程度であるかという問題であ る。― 個人の流動性選好は、様々な状況で資産(貨幣あるいは単位賃金数で測った)を貨幣での保有を希望する量のグラフによって表される。

  We shall find that the mistake in the accepted theories of the rate of interest lies in their attempting to derive the rate of interest from the first of these two constituents of psychological time-preference to the neglect of the second; and it is this neglect which we must endeavour to repair.

  現行の利子率理論の間違いは、利子率が時間選好のこの二つの心理的要因のうちの最初のものだけから説明されていて、二番目のものを無視していることである。

  It should be obvious that the rate of interest cannot be a return to saving or waiting(待忍) as such. For if a man hoards his savings in cash, he earns no interest, though he saves just as much as before. On the contrary, the mere definition of the rate of interest tells us in so many words that the rate of interest is the reward for parting with liquidity for a specified period. For the rate of interest is, in itself, nothing more than the inverse proportion between a sum of money and what can be obtained for parting with control over the money in exchange for a debt[1] for a stated period of time.[2]

  利子率が単に貯蓄や待忍(=消費を控えること)の報酬でないのは明らかである。というのは、貯蓄の量は同じでも現金で保有したら利子は稼げないからであ る。逆に、利子率の定義を見ればわかるが、そこで万言を費やして言われていることは、利子率とは流動性を一定期間手放すことに対する報酬なのである。それ はある金額と、その金額を債券[1]と交換に一定期間手放すことで得られる金額(=利子)の逆比率にほかならない[2]。

  Thus the rate of interest at any time, being the reward for parting with liquidity, is a measure of the unwillingness of those who possess money to part with their liquid control over it. The rate of interest is not the “price” which brings into equilibrium the demand for resources to invest with the readiness to abstain from present consumption. It is the “price” which equilibrates the desire to hold wealth in the form of cash with the available quantity of cash; ― which implies that if the rate of interest were lower, i.e. if the reward for parting with cash were diminished, the aggregate amount of cash which the public would wish to hold would exceed the available supply, and that if the rate of interest were raised, there would be a surplus of cash which no one would be willing to hold. If this explanation is correct, the quantity of money is the other factor, which, in conjunction with liquidity-preference, determines the actual rate of interest in given circumstances. Liquidity-preference is a potentiality or functional tendency, which fixes the quantity of money which the public will hold when the rate of interest is given; so that if r is the rate of interest, M the quantity of money and L the function of liquidity-preference, we have M = L(r). This is where, and how, the quantity of money enters into the economic scheme.

 つまり、いつの時点でも利子率とは、流動性を手放すことの報酬であるから、貨幣の所持者が貨幣に対する流動的支配を放棄することをどれほど嫌がっている かということを示す尺度である。利子率とは投資資金に対する需要(=資金需要、投資)と今の消費を控えたいという気持ち(=資金供給、貯蓄)を均衡させる 「価格」ではない。富を現金で保有したいという気持ち(=貨幣需要)と、社会に出回っている現金量(=貨幣供給)を均衡させる「価格」である。― これはどういうことかというと、もし利子率が下がって現金を手放すことに対する報酬が下がったら、みんなが現金を手元に置きたがって、その合計(=貨幣需 要)は社会で利用可能な貨幣供給を超えてしまうだろう。またもし利子率が上がれば、誰も現金を保持しようとしなくなって、現金があり余ってしまうだろう (=どちらも均衡が崩れる)。もしこの説明が正しければ、所与の環境において流動性選好と結びついて現行の利子率を決めるもう一つの要素として貨幣量があ ることになる。流動性選好とは潜在的な傾向、あるいは関数的な傾向であり、利子率が与えられた時に社会が保有しようとする貨幣量(=貨幣需要)を決めるも のである。そこで、もしrを利子率とし、Mを貨幣量とし、Lを流動性選好の関数とすると、M=L(r)(=あとでL2として再登場する、貨幣需要関数)。 こうして経済の仕組みの中に貨幣量が入ってくるのである。

  At this point, however, let us turn back and consider why such a thing as liquidity-preference exists. In this connection we can usefully employ the ancient distinction between the use of money for the transaction of current business and its use as a store of wealth. As regards the first of these two uses, it is obvious that up to a point it is worth while to sacrifice a certain amount of interest for the convenience of liquidity. But, given that the rate of interest is never negative, why should anyone prefer to hold his wealth in a form which yields little or no interest to holding it in a form which yields interest (assuming, of course, at this stage, that the risk of default is the same in respect of a bank balance as of a bond)? A full explanation is complex and must wait for Chapter 15. There is, however, a necessary condition failing which the existence of a liquidity-preference for money as a means of holding wealth could not exist.

 しかし、ここで振り返って流動性選好なるものがどうして存在するか考えてみよう。この関連においては、貨幣の用途として、当面の商取引のための用途と富 の蓄積のために用途という昔ながらの区別を使うのが便利である。この二つの用途のうちの最初のものについては、流動性という便宜を獲得するために多少の利 益を犠牲にする価値があるのは明らかである。しかし、利子率は決してマイナスになることはないのに、どうして利益をもたらす形でなく、利益をほとんどある いは全くもたらさない形で自分の富を保有しようとする人がいるのだろうか(もちろんこの段階では破産リスクは銀行預金も公債も同じだとする)。この完全な 説明は複雑で第15章を待たねばならない。しかしながら、富を保有する手段として貨幣の流動性選好が存在するためには、欠くことの出来ない必要条件が一つ ある。

  This necessary condition is the existence of uncertainty as to the future of the rate of interest, i.e. as to the complex of rates of interest(利子率複合体) for varying maturities which will rule at future dates. For if the rates of interest ruling at all future times could be foreseen with certainty, all future rates of interest could be inferred from the present rates of interest for debts(債権) of different maturities, which would be adjusted to the knowledge of the future rates. For example, if 1Dr is the value in the present year 1 of £1 deferred r years and it is known that nDr will be the value in the year n of £1 deferred r years from that date, we have

nDr = 1Dn+r / 1Dn ;

whence it follows that the rate at which any debt can be turned into cash n years hence is given by two out of the complex of current rates of interest. If the current rate of interest is positive for debts of every maturity, it must always be more advantageous to purchase a debt than to hold cash as a store of wealth.

  この必要条件とは将来の利子率に関する不確実性の存在である。利子率とはこの場合、将来の様々な日付を満期とする利子率複合体のことである。というのは、 仮にもし将来のあらゆる時点における支配的な利子率(=市場利子率)が確実に予知できるとすると、様々な満期を持つ債権の現在の利子率から、あらゆる将来 の利子率が推測できることになり、現代の利子率が将来の利子率の知識と合致するのである。例えば、もし1Drがr年後の1ポンドの現在年1の価値であっ て、nDrはn年からr年後の1ポンドのn年における価値となることがわかっているとすると
 
nDr=1Dn+r/1Dn が成り立つ(=1Dn+rはn+r年後の1ポンドの現在年1の価値)。

  この式から、今からn年後の債権(=nDr)が換金される利子率は現在の利子率複合体のうちの二つ(=1Drと1Dn+r)によって与えられることにな る。もし現行の利子率がどの満期の債権についてもプラスなら、富の蓄積としては現金で持つよりは債権を買うほうが常に有利であるということになるにちがい ない。

  If, on the contrary, the future rate of interest is uncertain<,> we cannot safely infer that ndr will prove to be equal to 1Dn+r / 1Dn when the time comes. Thus if a need for liquid cash may conceivably arise before the expiry of n years, there is a risk of a loss being incurred in purchasing a long-term debt and subsequently turning it into cash, as compared with holding cash. The actuarial profit or mathematical expectation of gain calculated in accordance with the existing probabilities ― if it can be so calculated, which is doubtful ― must be sufficient to compensate for the risk of disappointment.

  逆に、もし将来の利子率が不確実なら、nDrは1Dn+r/1Dnと等しいと確信を持って言うことができなくなる。つまり、n年が過ぎる前に現金が必要に なる場合には、現金で持っているのと比べて、長期の債権を購入して換金することは損失のリスクを招くことになる。統計上の利潤あるいは現在の確率に従って 計算された利益の数学的予想 ― もし計算できるならだが、疑わしい ― が損失のリスクを埋め合わせなければならない。

  There is, moreover, a further ground for liquidity-preference which results from the existence of uncertainty as to the future of the rate of interest, provided that there is an organised market for dealing in debts. For different people will estimate the prospects differently and anyone who differs from the predominant opinion as expressed in market quotations may have a good reason for keeping liquid resources in order to profit, if he is right, from its turning out in due course(いずれは判明する) that the 1dr's were in a mistaken relationship to one another.[3]

  さらに、債権を扱うために組織された市場の存在を前提にすれば、将来の利子率の不確実性から来る流動性選好の理由がもう一つある。というのは、将来の予想 については人によって考え方が異なるし、市場の相場に表れている支配的な考え方と異なる考えを持つ人が利益を得るためには、流動資産を持ち続けるのが正し いことになる。もし彼の予想が当たっていれば、1drのつながりは間違っていることがいずれ判明するからである[3]。

  This is closely analogous to what we have already discussed at some length in connection with the marginal efficiency of capital. Just as we found that the marginal efficiency of capital is fixed, not by the “best” opinion, but by the market valuation as determined by mass psychology, so also expectations as to the future of the rate of interest as fixed by mass psychology have their reactions on liquidity-preference; ― but with this addition that the individual, who believes that future rates of interest will be above the rates assumed by the market, has a reason for keeping actual liquid cash,[4] whilst the individual who differs from the market in the other direction will have a motive for borrowing money for short periods in order to purchase debts of longer term. The market price will be fixed at the point at which the sales of the “bears” and the purchases of the “bulls” are balanced.

  これは我々が資本の限界効率に関して詳しく議論したこととよく似ている。資本の限界効率は最善の意見によって決まるのではなく、大衆心理による市場の評価 によって決まるということを我々はすでに見たが、それと同じく、将来の利子率の予想もまた大衆心理によって決まるもので、それが流動性選好に影響を与える のである。―しかし、それだけではない。将来の利子率が現在の市場利子率より上ると思う人は、流動的な現金を[4]をもち続けるのが正しいことになる。一 方、それとは反対に将来の利子率が現在の市場利子率より下ると思う人は短期で金を借り入れて長期債権を買おうとするだろう。こうして「弱気筋」の売りと 「強気筋」の買いが均衡する点で、債権の市場価格は決まるのである。

  The three divisions of liquidity-preference which we have distinguished above may be defined as depending on (i) the transactions-motive, i.e. the need of cash for the current transaction of personal and business exchanges; (ii) the precautionary-motive, i.e. the desire for security as to the future cash equivalent of a certain proportion of total resources; and (iii) the speculative-motive, i.e. the object of securing profit from knowing better than the market what the future will bring forth. As when we were discussing the marginal efficiency of capital, the question of the desirability of having a highly organised market for dealing with debts presents us with a dilemma. For, in the absence of an organised market, liquidity-preference due to the precautionary-motive would be greatly increased; whereas the existence of an organised market gives an opportunity for wide fluctuations in liquidity-preference due to the speculative-motive.

  我々が上記に示した流動性選好の三つの分類(=商取引、富の蓄積、将来の利子率の不確定性)はそれぞれ(1)取引動機、つまり個人や企業が現在取引するた めの現金の必要性、(2)予備的動機、つまり全資産のある割合を将来における現金として持つことで安心しようとする欲求、(3)投機的動機、つまり将来に 関して市場よりもすぐれた知恵をもっていることで利益を確保しようとする目的、の三つの動機によるものである。我々が資本の限界効率を論じた時と同じく、 債権を扱うための高度に組織された市場をもつことが望ましいかどうかという問題もまた我々に一つのジレンマをもたらす(=思惑中心の投機が優勢になる)。 というのは、もし組織化された市場がなければ、予備的動機からくる流動性選好はますます大きくなるだろう。その一方、組織化された市場があるために、投機 的な動機から来る流動性選好が大きく変動する機会が生まれているのである。

  It may illustrate the argument to point out that, if the liquidity-preferences due to the transactions-motive and the precautionary-motive are assumed to absorb a quantity of cash which is not very sensitive to changes in the rate of interest as such and apart from(~を考えずにそれ自体として) its reactions on the level of income, so that the total quantity of money, less this quantity, is available for satisfying liquidity-preferences due to the speculative-motive, the rate of interest and the price of bonds have to be fixed at the level at which the desire on the part of certain individuals to hold cash (because at that level they feel “bearish” of the future of bonds) is exactly equal to the amount of cash available for the speculative-motive.

  このことを説明するためには、次の事を指摘するのがよいだろう。取引動機と予備的動機に基づく流動性選好が(所得水準に対する影響は考えずにそれ自体とし ての)利子率の変化に反応しない大量の現金を吸収して、この量を引いた総貨幣量が投機的動機に基づく流動性選好を満たすために利用可能であるとすると、投 機的動機のためのこの現金量(=貨幣供給)が、(その水準では債券の将来について弱気であるために)現金を持ちたい人達の欲望(=貨幣需要)とちょうど一 致するところで、利子率と債券価格が決まるのである。
 
Thus each increase in the quantity of money must raise the price of bonds sufficiently to exceed the expectations of some “bull” and so influence him to sell his bond for cash and join the “bear” brigade. If, however, there is a negligible demand for cash from the speculative-motive except for a short transitional interval, an increase in the quantity of money will have to lower the rate of interest almost forthwith, in whatever degree is necessary to raise employment and the wage-unit sufficiently to cause the additional cash to be absorbed by the transactions-motive and the precautionary-motive.

つまり、貨幣量の増加によって強気筋の予想を超えるほど債券価格が上がると、債券を売って現金化して弱気筋の仲間入りせざるをえないのである。しかし、そ の投機的動機からの現金需要もごく短い過渡期だけで取るに足らない場合には、貨幣量の増加で利子率は即座に下がらざるをえないが、それは雇用と単位賃金の 引き上げに必要な程度であり、増えた現金は取引動機と予備的動機によって吸収されてしまう。

  As a rule, we can suppose that the schedule of liquidity-preference relating the quantity of money to the rate of interest is given by a smooth curve which shows the rate of interest falling as the quantity of money is increased. For there are several different causes all leading towards this result.

 一般に、貨幣量と利子率とを結びつける流動性選好表は貨幣量の増加と利子率の低下が連動することを示す滑らかな曲線になると考えられる。というのは、いくつかの異なった原因があるが全てはこの結果に至るからである。
 
  In the first place, as the rate of interest falls, it is likely, cet. par., that more money will be absorbed by liquidity-preferences due to the transactions-motive. For if the fall in the rate of interest increases the national income, the amount of money which it is convenient to keep for transactions will be increased more or less proportionately to the increase in income; whilst, at the same time, the cost of the convenience of plenty of ready cash in terms of loss of interest will be diminished. Unless we measure liquidity-preference in terms of wage-units rather than of money (which is convenient in some contexts), similar results follow if the increased employment ensuing on a fall in the rate of interest leads to an increase of wages, i.e. to an increase in the money-value of the wage-unit. In the second place, every fall in the rate of interest may, as we have just seen, increase the quantity of cash which certain individuals will wish to hold because their views as to the future of the rate of interest differ from the market views.

  まず第一に、利子率が低下すれば、他の条件が同じとして、取引動機の流動性選好によって多くの貨幣が吸収されるだろう。というのは、もし利子率が低下した ために国民所得が増加したら、取引目的で保有しておくのが好都合な貨幣量が所得の増加に比例して増えるからである。一方、それと同時に、利子率が低下した おかげで、大量の現金を持つ代償として利子を失う機会費用は低減されている。流動性選好を貨幣ではなく単位賃金数で測ら(ある文脈では便利である)ない限 り、利子率の低下からくる雇用の増加が賃金の上昇をもたらして単位賃金の貨幣価値を増加させるから、同様の結果になる。第二に、今見たように、利子率が低 下するたびに(=債券価格が上昇)、ある人々が将来の利子率に対する見方が市場の見方と異なるために保有したいと思う現金量が増加する。

  Nevertheless, circumstances can develop in which even a large increase in the quantity of money may exert a comparatively small influence on the rate of interest. For a large increase in the quantity of money may cause so much uncertainty about the future that liquidity-preferences due to the security-motive may be strengthened; whilst opinion about the future of the rate of interest may be so unanimous that a small change in present rates may cause a mass movement into cash. It is interesting that the stability of the system and its sensitiveness to changes in the quantity of money should be so dependent on the existence of a variety of opinion about what is uncertain. Best of all that we should know the future. But if not, then, if we are to control the activity of the economic system by changing the quantity of money, it is important that opinions should differ. Thus this method of control is more precarious in the United States, where everyone tends to hold the same opinion at the same time, than in England where differences of opinion are more usual.

  それにも関わらず、貨幣量が大きく増えても利子率があまりを影響を受けないような状況もありうる。というのは、貨幣量が大きく増えると将来の不確実性も大 きくなり予備的な動機による流動性選好が強まることがあるからである。その一方、将来の利子率についての考えが全員一致している場合は、現行利子率の少し の変化でも現金化の動きが一斉に起きかねない。おもしろいことに、経済の安定性および貨幣量の変化に対する経済の敏感さは、不確実性に対する多様な意見が 存在することに依存しているのである。未来が予知できるのが一番いいのだが、それが不可能な場合には、貨幣量を変えることで経済活動を制御するつもりな ら、多様な意見が存在することが重要である。この点で、合衆国は全員が同時に同じ意見を持つ傾向があるので、多様な意見が存在する英国よりも、この制御方 法はうまくいきそうにない。
 
III

  We have now introduced money into our causal nexus for the first time, and we are able to catch a first glimpse of the way in which changes in the quantity of money work their way into the economic system. If, however, we are tempted to assert that money is the drink which stimulates the system(経済システム) to activity, we must remind ourselves that there may be several slips between the cup and the lip. For whilst an increase in the quantity of money may be expected, cet. par., to reduce the rate of interest, this will not happen if the liquidity-preferences of the public are increasing more than the quantity of money; and whilst a decline in the rate of interest may be expected, cet. par., to increase the volume of investment, this will not happen if the schedule of the marginal efficiency of capital is falling more rapidly than the rate of interest; and whilst an increase in the volume of investment may be expected, cet. par., to increase employment, this may not happen if the propensity to consume is falling off. Finally, if employment increases, prices will rise in a degree partly governed by the shapes of the physical supply functions, and partly by the liability of the wage-unit to rise in terms of money. And when output has increased and prices have risen, the effect of this on liquidity-preference will be to increase the quantity of money necessary to maintain a given rate of interest.

第3節

 我々は今や初めて因果関係の中に貨幣を導入した。我々は貨幣量の変化が経済の中でどのような働きするかを初めてうかがい知ることができるのである。しか しながら、貨幣こそは経済に活力を与える飲料であると主張しようと思っても、コップと唇の間には幾多の行き違いが存在することを忘れてはならない。という のは、他の条件が同じなら、貨幣量が増えると利子率が下がると思われているが、これは社会の流動性選好が増加して、それが貨幣量を上回る場合には成り立た ないのである。また、他の条件が同じなら、利子率が下がると投資量が増えると思われているが、これは消費性向が下がっている場合には成り立たないのであ る。最後に、もし雇用が増加すると、物理的な供給関数の形状と、貨幣で測った単位賃金が上昇する傾向によって左右される程度に、物価が上昇する。そして産 出量が増加して物価が上昇した時には、流動性選好が影響を受けて、一定の利子率を維持するために必要な貨幣量が増えるのである。

IV

  Whilst liquidity-preference due to the speculative-motive corresponds to what in my Treatise on Money I called “the state of bearishness”, it is by no means the same thing. For “bearishness” is there defined as the functional-relationship, not between the rate of interest (or price of debts) and the quantity of money, but between the price of assets and debts, taken together, and the quantity of money. This treatment, however, involved a confusion between results due to a change in the rate of interest and those due to a change in the schedule of the marginal efficiency of capital, which I hope I have here avoided.

第4節
  投機的動機による流動性選好は『貨幣論』では私が「弱気の状態」と呼んだものであるが、両者は同じものではない。というのは、その本では「弱気」とは利子 率(または債権価格)と貨幣量の相関関係ではなく、資産と債権を合わせた価格と貨幣量との関係と定義されているからである。しかし、あの論文は利子率の変 化の結果と資本の限界効率表の変化の結果を混同していた。今回はその混同を避けられたと思う。

V

The concept of Hoarding may be regarded as a first approximation to the concept of Liquidity-preference. Indeed if we were to substitute “propensity to hoard” for “hoarding”, it would come to substantially the same thing. But if we mean by “hoarding” an actual increase in cash-holding, it is an incomplete idea ― and seriously misleading if it causes us to think of “hoarding” and “not-hoarding” as simple alternatives. For the decision to hoard is not taken absolutely or without regard to the advantages offered for parting with liquidity; ― it results from a balancing of advantages, and we have, therefore, to know what lies in the other scale. Moreover it is impossible for the actual amount of hoarding to change as a result of decisions on the part of the public, so long as we mean by “hoarding” the actual holding of cash. For the amount of hoarding must be equal to the quantity of money (or ― on some definitions ― to the quantity of money minus what is required to satisfy the transactions-motive); and the quantity of money is not determined by the public. All that the propensity of the public towards hoarding can achieve is to determine the rate of interest at which the aggregate desire to hoard becomes equal to the available cash. The habit of overlooking the relation of the rate of interest to hoarding may be a part of the explanation why interest has been usually regarded as the reward of not-spending, whereas in fact it is the reward of not-hoarding.

第4節
  保蔵(=金を貯めこむ)という概念は流動性選好という概念と非常に似ているように思えるかもしれない。確かにもし「保蔵」を「保蔵性向」という意味で使う なら、流動性選好とほぼ同じことになる。しかし、もし「保蔵」を現金所有の増加の意味だとすると、それは不完全であるし、そこから保蔵と非保蔵が単なる選 択肢であると考えるなら全くの誤解である。というのは、保蔵の決定は独立したものではないし、流動性を手放すことへの報酬と無関係ではないからである。― つまり、保蔵の決定は利益の均衡の結果なのである。したがって、我々は天秤のもう一方には何が乗っているかを知らなければならない。さらに、保蔵の意味が 現金を所有することなら、保蔵量が社会の決定で変化することはあり得ない。というのは、保蔵量は貨幣量(または、ある定義では、取引動機を満たすために必 要な貨幣量を引いた量)と等しくなければならないからである。そして、貨幣量は社会が決めるものではないのである。社会の保蔵性向がなしうることは、全体 の保蔵欲が現金量と等しくなるような利子率を決定することだけである。利子率と保蔵との関係を無視する習慣があるために、利子は消費しないことの報酬だと 一般に見做されているのである。実際には利子は保蔵しないことの報酬なのである。

Author's Footnotes

[1]. Without disturbance to this definition, we can draw the line between “money” and “debts” at whatever point is most convenient for handling a particular problem. For example, we can treat as money any command over general purchasing power which the owner has not parted with for a period in excess of three months, and as debt what cannot be recovered for a longer period than this; or we can substitute for “three months” one month or three days or three hours or any other period; or we can exclude from money whatever is not legal tender(法貨、通貨) on the spot. It is often convenient in practice to include in money time-deposits(定期預金) with banks and, occasionally, even such instruments(証券) as (e.g.) treasury bills(大蔵省証券). As a rule, I shall, as in my Treatise on Money, assume that money is coextensive(同じ広がりを持つ) with bank deposits(銀行預金).

[2]. In general discussion, as distinct from specific problems where the period of the debt is expressly specified, it is convenient to mean by the rate of interest the complex of the various rates of interest current for different periods of time, i.e. for debts of different maturities.

[3]. This is the same point as I discussed in my Treatise on Money under the designation of the two views and the “bull-bear” position.

[4]. It might be thought that, in the same way, an individual, who believed that the prospective yield of investments will be below what the market is expecting, will have a sufficient reason for holding liquid cash. But this is not the case. He has a sufficient reason for holding cash or debts in preference to equities; but the purchase of debts will be a preferable alternative to holding cash, unless he also believes that the future rate of interest will prove to be higher than the market is supposing.

著者注

[1] 「貨幣」と「債権」の間の線引は特定の問題を扱うのに便利な場所に引けばよいのであって、それによって利子率のこの定義が影響を受けることはな い。例えば、貨幣を「3ヶ月を越えて手放すことのなかった一般的な購買力」のことにして、債権を「3ヶ月より長い期間利用できない購買力」としてもよい。 あるいは、この3ヶ月を1ヶ月にしてもいいし、3日にしてもいいし、どんな期間にしてもいいのだ。あるいは貨幣の範疇から現金でない法定通貨を排除しても よい。あるいは、銀行の定期預金を貨幣の中に含めるのが実用的かもしれない。あるいは場合によっては財務証券のような証券を含めるのも便利だろう。一般的 に、自著『貨幣論』と同じく、私は銀行預金は貨幣のうちに含めて考えることにしている。

[2] 一般的な議論では、債権の期間は明示されている特殊な問題は別として、利子率として様々な期間を持つ様々な現行の利子率の複合体、すなわち様々な満期を持つ債権の利子率複合体を考えるのが便利である。

[3] これは自著『貨幣論』で「二つの見方と『強気・弱気筋』」として論じたのと同じである。

[4] 同様にして、投資物件の見込み収益が市場の予想よりも下回ると思う人は、流動的な現金を保有する充分な理由があると思えるかもしれないが、これは 間違っている。その場合には、株式よりも現金か債権を保有したくなる充分な理由になるだけである。しかし、それと同時に将来の利子率が市場の予想よりも高 くなると思えない場合には、現金保有よりも債権の購入が望ましく思えるだろう。


Chapter 14. The Classical Theory of the Rate of Interest
第14章 利子率についての古典的理論
I

  WHAT is the Classical Theory of the Rate of Interest? It is something upon which we have all been brought up and which we have accepted without much reserve until recently. Yet I find it difficult to state it precisely or to discover an explicit account of it in the leading treatises of the modern classical school.[1]

第1節

  利子率についての古典派の理論はどういうものだろう。我々は古典派の理論と共に成長しその理論を最近までほとんど無条件に受け入れてきた。しかし、それが どういうものかを正確に記述することは難しいし、近代古典派の主な論文の中にその明確な記述を見つけることも難しい[1]。

  It is fairly clear, however, that this tradition has regarded the rate of interest as the factor which brings the demand for investment and the willingness to save into equilibrium with one another. Investment represents the demand for investable resources and saving represents the supply, whilst the rate of interest is the “price” of investable resources at which the two are equated. Just as the price of a commodity is necessarily fixed at that point where the demand for it is equal to the supply, so the rate of interest necessarily comes to rest under the play of market forces at the point where the amount of investment at that rate of interest is equal to the amount of saving at that rate.

  しかし、利子率は古典派の伝統では投資需要と貯蓄志向に相互の均衡をもたらす要素であると見做されてるのは明らかである。投資とは投資可能な資金に対する 需要、貯蓄とはその供給を意味する。それに対して、利子率とはこの二つが一致する投資可能な資金の「価格」である。商品の価格がその需要と供給の一致する 地点で必ず決まるように、市場の力の作用のもとで、利子率は投資量と貯蓄量とがそこで一致する地点で必ず安定するのである。

  The above is not to be found in Marshall's Principles in so many words. Yet his theory seems to be this, and it is what I myself was brought up on and what I taught for many years to others. Take, for example, the following passage from his Principles: “Interest, being the price paid for the use of capital in any market, tends towards an equilibrium level such that the aggregate demand for capital in that market, at that rate of interest, is equal to the aggregate stock(資本) forthcoming at that rate”.[2] Or again in Professor Cassel's Nature and Necessity of Interest it is explained that investment constitutes the “demand for waiting” and saving the “supply of waiting”, whilst interest is a “price” which serves, it is implied, to equate the two, though here again I have not found actual words to quote. Chapter vi. of Professor Carver's Distribution of Wealth clearly envisages interest as the factor which brings into equilibrium the marginal disutility of waiting with the marginal productivity of capital.[3]

  これはそのままマーシャルの『原理』に出てくるわけではない。しかし、彼の利子率の理論はこれだし、私が育ったのも私が教えてきたのもこれである。例え ば、彼の『原理』から次の文章を引用してみよう。「利子は、市場で資本の使用に対して支払われる代価であって、市場における資本の総需要がその利子率で供 給される総資本ストックと一致するような均衡レベルに向かう。」[2]。あるいは、カッセル教授の『利子の性質と必然性』では、「待忍に対する需要」が投 資であり「待忍からの供給」が貯蓄であるが、一方、利子はこの二つを一致させる価格であるとされている。ただし、ここでも直接そういう言葉を使っているわ けでない。カーヴァー教授の『富の分配』の第4章では、明らかに、利子は「待忍の限界不効用」と「資本の限界生産性」を均衡させる要因であると見做されて いる。
 
Sir Alfred Flux (Economic Principles, p. 95) writes: “If there is justice in the contentions of our general discussion, it must be admitted that an automatic adjustment takes place between saving and the opportunities for employing capital profitably. ... Saving will not have exceeded its possibilities of usefulness ... so long as the rate of net interest is in excess of zero.” Professor Taussig (Principles, vol., ii. p. 29) draws a supply curve of saving and a demand curve representing “the diminishing productiveness of the several instalments of capital”, having previously stated (p. 20) that “the rate of interest settles at a point where the marginal productivity of capital suffices to bring out the marginal instalment of saving”.[4] Walras, in Appendix I. (III.) of his Elements d'economie pure, where he deals with “l'echange d'epargnes contre capitaux neufs”, argues expressly that, corresponding to each possible rate of interest, there is a sum which individuals will save and also a sum which they will invest in new capital assets, that these two aggregates tend to equality with one another, and that the rate of interest is the variable which brings them to equality; so that the rate of interest is fixed at the point where saving, which represents the supply of new capital, is equal to the demand for it. Thus he is strictly in the classical tradition.

アルフレッド・フラックス卿(『経済原理』95頁)にはこう書いている。「我々の一般的な議論が正しければ、資本の有利な利用機会と貯蓄との間には自動的 な調整が働くことを認めなければならない・・・利子率がゼロ以上であるかぎり・・・貯蓄がいくら増えても有利さを失うことはない」。タウシング教授(『原 理』第2巻29頁)は貯蓄の供給曲線と「資本の逐次投入の生産性の逓減」を表す需要曲線を描いているが、その前に(20頁)「利子率は資本の限界生産性が 貯蓄の限界投入を引き出す地点で決まる」と書いている[4]。ワルラスは『純粋経済学要綱』付録ⅠのⅢの「貯蓄と新資本の交換」を扱っているところで、次 のように書いている。利子率のそれぞれの値に対応して個人が貯蓄する金額と新資本資産に投資する金額が存在すること、この二つの総量は相互に一致する傾向 があること、利子率はこの二つを一致させる変数であること、その結果、利子率は新投資の供給である貯蓄が新投資に対する需要と等しくなる点で決まると。つ まり、彼は厳密なほどに古典派の伝統に従っているのである。

  Certainly the ordinary man ― banker, civil servant or politician ― brought up on the traditional theory, and the trained economist also, has carried away with him the idea that whenever an individual performs an act of saving he has done something which automatically brings down the rate of interest, that this automatically stimulates(増加させる) the output of capital, and that the fall in the rate of interest is just so much as is necessary to stimulate the output of capital to an extent which is equal to the increment of saving; and, further, that this is a self-regulatory process of adjustment which takes place without the necessity for any special intervention or grandmotherly care on the part of the monetary authority. Similarly ― and this is an even more general belief, even to-day ― each additional act of investment will necessarily raise the rate of interest, if it is not offset by a change in the readiness to save.

  確かに伝統的理論で成長した一般人―銀行家や役人や政治家―も専門の経済学者も、次のような考え方をもっている。つまり、「個人が貯蓄すると自動的に利子 率が下がり、これが資本の産出量を自動的に増加させる」。また「利子率は資本の産出量が増加して貯蓄の増加と等しくなるまで必然的に下がる」。さらに「こ の過程は自動的な調整過程であって、貨幣当局による介入やお節介を必要としない」という考え方である。同様に、「もし貯蓄志向の変化によって相殺されない 場合には、投資の増やす行為は必ず利子率を引き上げる」という考え方は、さらに一般的なものである。

  Now the analysis of the previous chapters will have made it plain that this account of the matter must be erroneous. In tracing to its source the reason for the difference of opinion, let us, however, begin with the matters which are agreed.

  これまでの章の分析によれば、問題に対するこの記述が間違っていることは明らかだろう。しかし、この考えの違いの原因を根源まで遡りながら、まずは意見が一致している事から始めよう。

  Unlike the neo-classical school, who believe that saving and investment can be actually unequal, the classical school proper has accepted the view that they are equal. Marshall, for example, surely believed, although he did not expressly say so, that aggregate saving and aggregate investment are necessarily equal. Indeed, most members of the classical school carried this belief much too far; since they held that every act of increased saving by an individual necessarily brings into existence a corresponding act of increased investment. Nor is there any material difference, relevant in this context, between my schedule of the marginal efficiency of capital or investment demand-schedule and the demand curve for capital contemplated by some of the classical writers who have been quoted above. When we come to the propensity to consume and its corollary the propensity to save, we are nearer to a difference of opinion, owing to the emphasis which they have placed on the influence of the rate of interest on the propensity to save.

  貯蓄と投資は実際には一致しないと信じる新古典派とちがって、古典派の学者たちはこの二つが一致するという考えを受け入れてきた。例えば、マーシャルは自 分ではそうは言わないが、総貯蓄と総投資は必然的に一致すると確かに信じていた。なるほど、多くの古典派経済学者はこの信念を推し進めすぎている。という のは、貯蓄を増やすあらゆる行為は必然的にそれに対応して投資を増やす行為を存在させると信じているからである。また、この点に関して、私の資本の限界効 率表あるいは投資需要表と、ここで引用した古典派の学者たちが考える資本の需要曲線との間に大きな違いはない。しかし、消費性向とその裏返しである貯蓄性 向の話になると、見解の相違点に近づいてくる。彼らは利子率が貯蓄性向に与える影響を強調するからである。
 
But they would, presumably, not wish to deny that the level of income also has an important influence on the amount saved; whilst I, for my part, would not deny that the rate of interest may perhaps have an influence (though perhaps not of the kind which they suppose) on the amount saved out of a given income. All these points of agreement can be summed up in a proposition which the classical school would accept and I should not dispute; namely, that, if the level of income is assumed to be given, we can infer that the current rate of interest must lie at the point where the demand curve for capital corresponding to different rates of interest cuts the curve of the amounts saved out of the given income corresponding to different rates of interest.

しかし、おそらく彼らは所得水準が貯蓄額に重要な影響を与えることを否定するつもりはない。一方、私としても、利子率が所得から貯蓄される割合に影響(た だし彼らが考える影響ではない)を与えることを否定するつもりはない。これらの意見の一致点はどちらも、古典派の学者たちが受け入れて私も拒否しない一つ の命題に要約できる。すなわち、もし所得水準が一定なら、様々な利子率に対応する資本の需要曲線が、所得から貯蓄される量を様々な利子率と結びつける曲線 と交わる点で現行利子率が決まるという命題である。

  But this is the point at which definite error creeps into the classical theory. If the classical school merely inferred from the above proposition that, given the demand curve for capital and the influence of changes in the rate of interest on the readiness to save out of given incomes, the level of income and the rate of interest must be uniquely correlated, there would be nothing to quarrel with. Moreover, this proposition would lead naturally to another proposition which embodies an important truth; namely, that, if the rate of interest is given as well as the demand curve for capital and the influence of the rate of interest on the readiness to save out of given levels of income, the level of income must be the factor which brings the amount saved to equality with the amount invested. But, in fact, the classical theory not merely neglects the influence of changes in the level of income, but involves formal error.

  しかし、まさにこの点で古典派の理論にはっきり間違いが入り込んで来ている。もし古典派の学者たちがこの命題から推測して、資本の需要曲線と、所得水準 と、貯蓄志向に対する利子率の変化の影響を一定とするとき、所得水準と利子率が一意的に相関しているというなら、何も文句はない。さらに、当然この命題は 重要な真実を体現しているもうひとつの命題に至る。それは即ち、資本の需要曲線と、所得水準と、貯蓄志向に対する利子率の変化の影響だけでなく、利子率も 一定なら、その所得水準が貯蓄量と投資量を一致させる要素である。しかし、実際には、古典派の理論は所得水準の変化の影響を無視するだけでなく、形式的な 誤りも犯している。

  For the classical theory, as can be seen from the above quotations, assumes that it can then proceed to consider the effect on the rate of interest of (e.g.) a shift in the demand curve for capital, without abating or modifying its assumption as to the amount of the given income out of which the savings are to be made. The independent variables of the classical theory of the rate of interest are the demand curve for capital and the influence of the rate of interest on the amount saved out of a given income; and when (e.g.) the demand curve for capital shifts, the new rate of interest, according to this theory, is given by the point of intersection between the new demand curve for capital and the curve relating the rate of interest to the amounts which will be saved out of the given income. The classical theory of the rate of interest seems to suppose that, if the demand curve for capital shifts or if the curve relating the rate of interest to the amounts saved out of a given income shifts or if both these curves shift, the new rate of interest will be given by the point of intersection of the new positions of the two curves.

 というのは、古典派の理論は、先の引用からも分かるように、資本の需要曲線のシフトが利子率に与える影響を考える時に、所得水準が一定という想定を変え ないでいいと考えているからである。利子率の古典派理論の独立変数は、資本の需要曲線と、貯蓄志向に対する利子率の変化の影響である。そして資本の需要曲 線がシフトした時には、この理論によれば、新たな利子率は、新たな資本の需要曲線と、所得から貯蓄される量を様々な利子率と結びつける曲線と交わる点で得 られる。利子率の古典派理論では、資本の需要曲線がシフトするか、所得から貯蓄される量を様々な利子率と結びつける曲線がシフトするか、両方の曲線がシフ トする場合には、この二つの曲線の新たな交点によって新たな利子率が得られるというのである。
 
But this is a nonsense theory. For the assumption that income is constant is inconsistent with the assumption that these two curves can shift independently of one another. If either of them shift, then, in general, income will change; with the result that the whole schematism based on the assumption of a given income breaks down. The position could only be saved by some complicated assumption providing for an automatic change in the wage-unit of an amount just sufficient in its effect on liquidity-preference to establish a rate of interest which would just offset the supposed shift, so as to leave output at the same level as before. In fact, there is no hint to be found in the above writers as to the necessity for any such assumption; at the best it would be plausible only in relation to long-period equilibrium and could not form the basis of a short-period theory; and there is no ground for supposing it to hold even in the long-period. In truth, the classical theory has not been alive to the relevance of changes in the level of income or to the possibility of the level of income being actually a function of the rate of the investment.

しかし、これはナンセンスな理論である。というのは、所得が一定であるという想定は、この二つの曲線が互いに独立してシフトするという想定と両立しないか らである。もしどちらか一方がシフトしたら、ふつう所得は変化する。その結果、所得を一定とする全体の図式は崩壊するのである。この図式を救えるのは、あ る種の複雑な想定だけである。それは単位賃金が自動的に変化して流動性選好に影響を与えて、曲線のシフトを相殺するような利子率をもたらして、その結果、 産出量を以前と同じに保つと想定することである。実際、上記の学者たちはそんな想定が必要だとは考えているようには見えない。うまくいっても、そのような 想定は長期均衡との関連ではありうるが、短期理論の基礎とは成り得ないし、長期においても維持できると考える理由はない。事実、古典派理論は所得水準の変 化の重要性やあるいは所得水準が投資量の関数である可能性には気づいていなかったのである。

  The above can be illustrated by a diagram[5] as follows:

 このことは次のグラフで説明できる。グラフは略
 
  In this diagram the amount of investment (or saving) I is measured vertically, and the rate of interest r horizontally. X1X1' is the first position of the investment demand-schedule, and X2X2' is a second position of this curve. The curve Y1 relates the amounts saved out of an income Y1 to various levels of the rate of interest, the curves Y2, Y3, etc., being the corresponding curves for levels of income Y2, Y3, etc. Let us suppose that the curve Y1 is the Y-curve consistent with an investment demand-schedule X1X1' and a rate of interest r1. Now if the investment demand-schedule shifts from X1X1' to X2X2', income will, in general, shift also. But the above diagram does not contain enough data to tell us what its new value will be; and, therefore, not knowing which is the appropriate Y-curve, we do not know at what point the new investment demand-schedule will cut it. If, however, we introduce the state of liquidity-preference and the quantity of money and these between them tell us that the rate of interest is r2, then the whole position becomes determinate.
 
  このグラフでは投資量(あるいは貯蓄量)Iを横軸に、利子率rを縦軸におく。X1X1'は投資需要表(=資本の需要曲線)の最初の位置であり、X2X2' はこの曲線の二番目の位置である。曲線Y1は所得Y1から貯蓄される量を様々な利子率と結びつける曲線である。曲線Y2、Y3等々も同様に所得レベル Y2、Y3等々に対応している。曲線Y1は投資需要表X1X1'と利子率r1と一致するY曲線であるとする。いま投資需要表がX1X1'からX2X2'へ シフトすると、一般的には所得もシフトする。しかし、このグラフでは充分なデータがないので所得の新しい値は分からない。したがって、Y曲線のどれが正し い曲線かわからないと、新たな投資需要表がどこでY曲線と交わるかわからない。しかし、もし我々が流動性選好の状態と貨幣量を導入して、この二つから利子 率がr2であることが分かると、全ての位置が確定する。

For the Y-curve which intersects X2X2' at the point vertically above r2, namely, the curve Y2, will be the appropriate curve. Thus the X-curve and the Y-curves tell us nothing about the rate of interest. They only tell us what income will be, if from some other source we can say what the rate of interest is. If nothing has happened to the state of liquidity-preference and the quantity of money, so that the rate of interest is unchanged, then the curve Y'2 which intersects the new investment demand-schedule vertically below the point where the curve Y1 intersected the old investment demand-schedule will be the appropriate Y-curve, and Y'2 will be the new level of income.

というのは、X2X2'とr2の上の点で交わるY曲線、つまり曲線Y2が正しい曲線だとわかるからである。つまり、X曲線とY曲線は利子率については何も 教えてくれない。そこから所得がわかるのは何らかの資料から利子率が分かった場合だけである。もし流動性選好の状態と貨幣量に何も起こらず、利子率に変化 がなかったら、新たな投資需要表と曲線Y1が元の投資需要表と交わる点の下で交わる曲線Y2'が正しいY曲線だということになって、曲線Y2'が新たな所 得レベルとなる。

  Thus the functions used by the classical theory, namely, the response of investment and the response of the amount saved out of a given income to change in the rate of interest, do not furnish material for a theory of the rate of interest; but they could be used to tell us what the level of income will be, given (from some other source) the rate of interest; and, alternatively, what the rate of interest will have to be, if the level of income is to be maintained at a given figure (eg. the level corresponding to full employment).

 つまり、古典派理論が使う変動、すなわち、投資の利子率の変化に対する反応(=資本の需要曲線)、所得から貯蓄される量の利子率の変化に対する反応は、 利子率の理論のための材料を提供しない。しかし(ある別の理由から)利子率が一定であるなら、この二つを使って所得水準を知ることが出来る。また逆に、も し所得水準が一定(例えば完全雇用に対応する水準)に保たれるなら、この二つを使って利子率を知ることが出来る。

  The mistake originates from regarding interest as the reward for waiting as such, instead of as the reward for not-hoarding; just as the rates of return on loans or investments involving different degrees of risk, are quite properly regarded as the reward, not of waiting as such, but of running the risk. There is, in truth, no sharp line between these and the so-called “pure” rate of interest, all of them being the reward for running the risk of uncertainty of one kind or another. Only in the event of money being used solely for transactions and never as a store of value, would a different theory become appropriate.[6]

  間違いの原因は、利子を保蔵の報酬ではなく、待忍そのものの報酬と見なすことから来ている。それは、様々なレベルのリスクをもつ借り入れや投資からの利益 を、リスクの報酬ではなく、単なる待忍の報酬と見なすのが間違っているのと同じである。本当は、投資からの利益といわゆる純粋利子率との間に明確な区切り はない。どちらもある種の不確定性のリスクを冒すことの報酬なのである。貨幣が取引目的だけに使われ、価値の保有のために使われないときだけ、私の理論と は違う理論が正しいことになるだろう[6]。

  There are, however, two familiar points which might, perhaps, have warned the classical school that something was wrong. In the first place, it has been agreed, at any rate since the publication of Professor Cassel's Nature and Necessity of Interest, that it is not certain that the sum saved out of a given income necessarily increases when the rate of interest is increased; whereas no one doubts that the investment demand-schedule falls with a rising rate of interest. But if the Y-curves and the X-curves both fall as the rate of interest rises, there is no guarantee that a given Y-curve will intersect a given X-curve anywhere at all. This suggests that it cannot be the Y-curve and the X-curve alone which determine the rate of interest.

  しかし、二つのよく知られたことがあって、そのお陰で古典派の学者たちは何かが間違っていることに気づいてよかったのだ。第一に、カッセル教授の『利子の 性質と必然性』の出版以来、一定の所得から貯蓄される量は利子率の増加につれて必ず増える(=Y曲線は右上がり)とは言えなくなっているのは、誰もが認め ているのである。その一方で、投資需要表(=X曲線)は利子率の上昇とともに下降する(=右下がり)ことは誰も疑わない。しかし、利子率の上昇とともにY 曲線とX曲線がともに下降した場合に(=共に右下がり)、Y曲線とX曲線がどこかで交差するという保証はないのである。つまり、これは利子率を決定するこ とはY曲線とX曲線だけでは出来ないということである。

  In the second place, it has been usual to suppose that an increase in the quantity of money has a tendency to reduce the rate of interest, at any rate in the first instance and in the short period. Yet no reason has been given why a change in the quantity of money should affect either the investment demand-schedule or the readiness to save out of a given income. Thus the classical school have had quite a different theory of the rate of interest in Volume I dealing with the theory of value from what they have had in Volume II dealing with the theory of money. They have seemed undisturbed by the conflict and have made no attempt, so far as I know, to build a bridge between the two theories. The classical school proper, that is to say(少なくとも); since it is the attempt to build a bridge on the part of the neo-classical school which has led to the worst muddles of all. For the latter have inferred that there must be two sources of supply to meet the investment demand-schedule; namely, savings proper, which are the savings dealt with by the classical school, plus the sum made available by any increase in the quantity of money (this being balanced by some species of levy on the public, called “forced saving” or the like).
 
  第二に、貨幣量の増加は少なくとも最初と短期間は利子率を下げる傾向があると普通は思われている。しかし、なぜ貨幣量が投資需要表や貯蓄志向に影響を与え るか、その理由を古典派の学者たちは提供していない。つまり、古典派の学者たちは価値の理論を扱う第一巻と貨幣の理論を扱う第二巻で利子率について別々の 理論を立ててきたのだ。私の知るかぎり、彼らはこの矛盾を気にして来なかったし、この二つの理論の間を結ぶ橋を作ろうとして来なかった。少なくとも本来の 古典派経済学者はそうである。なぜなら、新古典派経済学はこの橋を作ろうとして最悪の泥沼に陥っているからである。というのは、新古典派経済学は投資需要 表に合わすために二つの投資源があるに違いないと推測した。すなわち、古典派が扱う本来の貯蓄のほかに貨幣量の増加によって利用可能となった金額(これは 「強制貯蓄」などと呼ばれる社会による一種の課税に相当する)である。

This leads on to the idea that there is a “natural” or “neutral”[6] or “equilibrium” rate of interest, namely, that rate of interest which equates investment to classical savings proper without any addition from “forced savings”; and finally to what, assuming they are on the right track at the start, is the most obvious solution of all, namely, that, if the quantity of money could only be kept constant in all circumstances, none of these complications would arise, since the evils supposed to result from the supposed excess of investment over savings proper would cease to be possible. But at this point we are in deep water. “The wild duck has dived down to the bottom ― as deep as she can get ― and bitten fast hold of the weed and tangle and all the rubbish that is down there, and it would need an extraordinarily clever dog to dive after and fish her up again.”

これがさらに「自然利子率」、「中立利子率」[6]、「均衡利子率」があるという考えに至る。つまり、投資と古典派のいう本来の貯蓄(強制貯蓄を含まな い)を等しくさせる利子率である。そして最後に、もし彼らの出発点が正しければ、すべての解決に至るのである。それは、貨幣量があらゆる状況において一定 に保てるならば、こうした難しい問題は一切発生しない。なぜなら、投資が本来の貯蓄を上回ることから来る害悪は存在しなくなるから、というのである。しか し、ここで我々は深い水の中に落ち込んでしまう。「野鴨は水底にどこまでも潜り込んだ。そしてそこの水草や藻やゴミに噛みついてしまった。その鴨をもうい ちど水中から引き上げるには、とてつもなく賢い犬が飛び込むしかなかった」。

  Thus the traditional analysis is faulty because it has failed to isolate correctly the independent variables of the system(経済システム). Saving and Investment are the determinates of the system, not the determinants. They are the twin results of the system's determinants, namely, the propensity to consume, the schedule of the marginal efficiency of capital and the rate of interest. These determinants are, indeed, themselves complex and each is capable of being affected by prospective changes in the others. But they remain independent in the sense that their values cannot be inferred from one another. The traditional analysis has been aware that saving depends on income but it has overlooked the fact that income depends on investment, in such fashion that, when investment changes, income must necessarily change in just that degree which is necessary to make the change in saving equal to the change in investment.

  つまり、古典派の分析は欠陥品なのだ。なぜなら、それは経済の独立変数を正確に取り出すことに失敗しているからである。貯蓄と投資は経済の被決定要因で あって、決定要因ではない。それらは経済の決定要因である消費性向と資本の限界効率と利子率の結果である。これらの決定要因は確かにそれ自身複雑であり、 自身以外の二つの変化の予想に影響される。しかし、これらのそれぞれの値は他の値からは相互に推測できないという意味では、それらは独立である。古典派の 分析は貯蓄が所得に依存することは知っていたが、所得が投資に依存することを見逃した。つまり、投資が変化すると所得は必然的に変化せざるを得ないので、 貯蓄の変化は投資の変化に必然的に一致することになるのである。

  Nor are those theories more successful which attempt to make the rate of interest depend on “the marginal efficiency of capital”. It is true that in equilibrium the rate of interest will be equal to the marginal efficiency of capital, since it will be profitable to increase (or decrease) the current scale of investment until the point of equality has been reached. But to make this into a theory of the rate of interest or to derive the rate of interest from it involves a circular argument, as Marshall discovered after he had got half-way into giving an account of the rate of interest along these lines.[8] For the “marginal efficiency of capital” partly depends on the scale of current investment, and we must already know the rate of interest before we can calculate what this scale will be. The significant conclusion is that the output of new investment will be pushed to the point at which the marginal efficiency of capital becomes equal to the rate of interest; and what the schedule of the marginal efficiency of capital tells us, is, not what the rate of interest is, but the point to which the output of new investment will be pushed, given the rate of interest.

  また、利子率を「資本の限界効率」に依存させようとする理論もそれよりましとはいえない。確かに均衡状態では利子率は資本の限界効率に等しくなる。この二 つが等しくなるまで現行の投資規模を増やす(あるいは減らす)のが有利だからである。しかし、ここから利子率の理論を作ろうとしたり、ここから利子率を導 き出そうとすると、循環論法に陥ることになる。それはマーシャルがこの考え方にそって利子率を説明しようとして途中で気づいたことである[8]。というの は、「資本の限界効率」は現行の投資規模に一部は依存し、しかも、この投資規模を計算するためにはあらかじめ利子率を知っておく必要があるからである。そ こから引き出される有意義な結論は、新たな投資の産出量は、資本の限界効率が利子率と等しくなるところまで拡大するということである。そして、資本の限界 効率表が我々に教えてくれることは、利子率がいくらであるかではなく、所与の利子率のもとで新投資の産出量がどこまで拡大するか、なのである。

  The reader will readily appreciate that the problem here under discussion is a matter of the most fundamental theoretical significance and of overwhelming practical importance. For the economic principle, on which the practical advice of economists has been almost invariably based, has assumed, in effect, that, cet. par., a decrease in spending will tend to lower the rate of interest and an increase in investment to raise it. But if what these two quantities determine is, not the rate of interest, but the aggregate volume of employment, then our outlook on the mechanism of the economic system will be profoundly changed. A decreased readiness to spend will be looked on in quite a different light if, instead of being regarded as a factor which will, cet. par., increase investment, it is seen as a factor which will, cet. par., diminish employment.

  読者はここで扱っている問題は最も基本的な理論上の意義をもち、実際上も圧倒的な重要性を持っていることを容易に理解してくれるだろう。というのは、経済 学者の実際上の助言が殆ど常に基づいている経済原理は、他の条件が同じなら「支出の減少は利子率を下げる傾向があり、投資の増加は利子率を引き上げる傾向 がある」と想定している。しかし、もしこの二つの量から決まるのが利子率ではなく総雇用量であるなら、我々の経済の仕組みに対する見方は大幅に変わるだろ う。また、もし支出性向の減少が、他の条件が同じなら投資を増やす要素であると見るかわりに、他の条件が同じなら雇用を減らす要因であると見るならば、支 出性向はまったく違う観点から眺められることになる。

Author's Footnotes

[1]. See the Appendix to this Chapter for an abstract of what I have been able to find.

[2]. Cf. Appendix p. 186 below for a further discussion of this passage.

[3]. Prof. Carver's discussion of Interest is difficult to follow (1) through his inconsistency as to whether he means by “marginal productivity of capital” quantity of marginal product or value of marginal product, and (2) through his making no attempt to define quantity of capital.

[4]. In a very recent discussion of these problems (“Capital, Time and the Interest Rate”, by Prof. F. H. Knight, Economica, August 1932), a discussion which contains many interesting and profound observations on the nature of capital, and confirms the soundness of the Marshallian tradition as to the uselessness of the Boehm-Bawerkian analysis, the theory of interest is given precisely in the traditional, classical mould. Equilibrium in the field of capital production means, according to Prof. Knight, “such a rate of interest that savings flow into the market at precisely the same time-rate or speed as they flow into investment producing the same net rate of return as that which is paid savers for their use”.

[5]. This diagram was suggested to me by Mr. R. F. Harrod. Cf. also a partly similar schematism by Mr. D. H. Robertson, Economic Journal, December 1934, p. 652.

[6]. Cf. Chapter 17 below.

[7]. The “neutral” rate of interest of contemporary economists is different both from the “natural” rate of Boehm-Bawerk and from the “natural” rate of Wicksell.

[8]. See the Appendix to this Chapter.

著者注

[1] 私が理解したことの要約はこの章の付録を見よ。

[2] この一節の詳細な議論はこの章の付録の186頁を参照。

[3] カーヴァー教授の利子の議論にはついて行けない。というのは、第一に、「資本の限界生産性」が限界生産量を意味しているのか限界生産価格を意味しているのかはっきりしないからであり、第二に、資本量を一切定義しようとしないからである。

[4] この問題の最新の議論(F.H.ナイト教授の「資本、時間、利子率」『エコノミカ』1932年8月号)では、資本の性格について非常に深淵で興味 深い観察が行われていて、ベーム・バーヴェルク式の分析の無用さに対するマーシャルの伝統の正しさを確認しており、利子理論がまさに伝統的古典的枠組みの 中で表わされている。資本生産の分野での均衡状態とは、ナイト教授によれば「貯蓄が市場に流入するスピードと貯蓄が投資に流入するスピードが同じで、貯蓄 した人に貯蓄の対価として支払われるのと同じ収益額がその投資によってもたらされるような利子率のことである」。

[5] このグラフはR.F.はロッド氏に教わったものである。『エコノミック・ジャーナル』1934年12月号652頁のD.H.ロバートソン氏の同様の図も参照。

[6] 17章参照。

[7] 現代の経済学者の「中立利子率」はベーム・バーヴェルクの「自然利子率」ともヴィックセルの「自然利子率」とも異なるものである。

[8] この章の付録を参照。


Appendix to Chapter 14. Appendix on the Rate of Interest in Marshall's “Principles of Economics”, Ricardo's “Principles of Political Economy”, and elsewhere

I

  THERE is no consecutive discussion of the rate of interest in the works of Marshall, Edgeworth or Professor Pigou, ― nothing more than a few obiter dicta(傍論). Apart from the passage already quoted above (p. 139) the only important clues to Marshall's position on the rate of interest are to be found in his Principles of Economics (6th edn.), Book VI. p. 534 and p. 593, the gist of which is given by the following quotations:

第14章への補足

第1節

  マーシャル、エッジワース、ピグー教授の著書には利子率についての一貫した議論は全く存在しない。あるのは二三の傍論だけである。マーシャルの利子率につ いての立場を知る鍵となる重要な文章は先に引用した(11章第2節139頁)もの以外では、彼の『経済原理』(第6版)の6巻534頁と593頁にあるも のだけである。その要点を以下の引用で示す。

  “Interest, being the price paid for the use of capital in any market, tends towards an equilibrium level such that the aggregate demand for capital in that market, at that rate of interest, is equal to the aggregate stock[1] forthcoming there at that rate. If the market, which we are considering, is a small one ― say a single town, or a single trade(産業) in a progressive country ― an increased demand for capital in it will be promptly met by an increased supply drawn from surrounding districts or trades. But if we are considering the whole world, or even the whole of a large country, as one market for capital, we cannot regard the aggregate supply of it as altered quickly and to a considerable extent by a change in the rate of interest. For the general fund of capital is the product of labour and waiting; and the extra work,[2] and the extra waiting, to which a rise in the rate of interest would act as an incentive, would not quickly amount to much, as compared with the work and waiting, of which the total existing stock of capital is the result. An extensive increase in the demand for capital in general will therefore be met for a time not so much by an increase of supply, as by a rise in the rate of interest; [3] which will cause capital to withdraw itself partially from those uses in which its marginal utility is lowest. It is only slowly and gradually that the rise in the rate of interest will increase the total stock of capital” (p. 534).

「利子は、市場で資本の使用に対して支払われる代価であって、市場における資本の総需要がその利子率で供給される総資本ストック[1]と一致するような均 衡レベルに向かう。もし我々の考える市場が小さいもの―例えば一つの町あるいは先進国の一つの産業―なら、資本需要の増加は周辺地域あるいは周辺産業から 引き出された供給の増加でただちに満たされるだろう。しかし、もし我々が資本市場として全世界、あるいは大きな国全体を考えるときには、資本需要を満たす ために資本の総供給が利子率の変化によって急激に大きく変化すると考えることは出来ない。資本となる一般的な資金は労働と待忍(=貯蓄)の産物であり、利 子率の上昇がインセンティブとなって、労働の増加[2]と待忍の増加があっても、それは現状の資本ストックを生み出した労働と待忍に比べると、急に大きな 量になることはない。そこで、一般的な資本需要の大幅な増加を満たすのは、当面は供給の増加ではなく利子率の上昇なのである[3]。利子率の上昇によっ て、資本の限界効用が最低な分野から資本が部分的に引き出されるのである。ただ利子率の上昇によって総資本ストックが増加するテンポは非常にゆっくりして いるだけなのである。(p534)」(=資本需要は小さな国では供給の増加によって満たされるが、大きな国では供給の増加ではなく利子率の上昇によって満 たされるが時間がかかる)


“It cannot he repeated too often that the phrase 'the rate of interest' is applicable to old investments of capital only in a very limited sense.[4] For instance, we may perhaps estimate that a trade capital of some seven thousand millions is invested in the different trades of this country at about 3 per cent net interest. But such a method of speaking, though convenient and justifiable for many purposes, is not accurate. What ought to be said is that, taking the rate of net interest on the investments of new capital in each of those trades [i.e. on marginal investments] to be about 3 per cent; then the aggregate net income rendered by the whole of the trade-capital invested in the various trades is such that, if capitalized(資本の割引現在価値を出す) at 33 years' purchase(毎年の収益) (that is, on the basis of interest at 3 per cent), it would amount to some seven thousand million pounds. For the value of the capital already invested in improving land or erecting a building<,> in making a railway or a machine, is the aggregate discounted value of its estimated future net incomes [or quasi-rents]; and if its prospective income-yielding power should diminish, its value would fall accordingly and would be the capitalised value of that smaller income after <allowing for> depreciation” (p. 593).

「『利子率』という言葉は古い資本投資に対しては非常に限られた意味でしか使えないということは、いくら繰り返してもよい[4]。たとえば、『約70億の 産業資本がこの国の様々な産業に約3%の純利子率で投資されている』と推測することがあるかもしれない。しかし、そのような言い方は、多くの目的に便利で 有効だけれども、不正確である。正しい言い方は、『それらの産業の各々に対する新資本の投資(つまり限界投資)の純利子率を約3%とすると、様々な産業に 投資された産業資本全体によってもたらされる総純所得は、毎年の収益の33年分(つまり利子率3%)で割引現在価値を計算すると約70億になる(←予想収 益/利子率=予想収益÷0.03=予想収益×100÷3=予想収益×33)』である。というのは、土地を整備したりビルを建てたり鉄道を引いたり機械を 作ったりすることに投資された資本の価値は、推定される将来の純所得(あるいは準地代)の総割引価値現在価値だからである。そして、もし資本の見込所得収 益力が減るとそれに応じて資本の価値も減るが、その価値は減価償却を差し引いて減った所得の割引現在価値となる。」(593頁)

  In his Economics of Welfare, (3rd edn.), p. 163, Professor Pigou writes: “The nature of the service of 'waiting' has been much misunderstood. Sometimes it has been supposed to consist in the provision of money, sometimes in the provision of time, and, on both suppositions, it has been argued that no contribution whatever is made by it to the dividend. Neither supposition is correct. 'Waiting' simply means postponing consumption which a person has power to enjoy immediately, thus allowing resources, which might have been destroyed, to assume the form of production instruments.[5] ... The unit of 'waiting ' is, therefore, the use of a given quantity of resources[6] ― for example, labour or machinery ― for a given time. ... In more general terms we may say that the unit of waiting is a year-value unit, or, in the simpler, if less accurate, language of Dr. Cassel, a year-pound. ... A caution may be added against the common view that the amount of capital accumulated in any year is necessarily equal to the amount of 'savings' made in it. This is not so, even when savings are interpreted to mean net savings, thus eliminating the savings of one man that are lent to increase the consumption of another, and when temporary accumulations of unused claims upon services in the form of bank-money are ignored; for many savings which are meant to become capital in fact fail of their purpose through misdirection into wasteful uses.”[7]

  ピグー教授はその著『厚生経済学』(第3版)の163頁で次のように書いている。「『待忍』の役割の性格は誤解されてきた。時にはそれは貨幣的備えである と思われ、時には時間的備えであると思われ、どちらの考え方をしても、分配分(=所得)に対しては何の貢献もしていないと主張されてきた。しかしどちらの 考え方も正しくない。『待忍』とは単に今すぐできる消費を延期することであって、失われたかもしれない資源に生産手段の姿をとること許すのである [5]。・・したがって『待忍』の単位は一定資源量[6]―例えば、労働や機械―の一定時間の利用である。・・もっと一般的な言葉でいえば、待忍の単位と は一年間の価値単位。あるいは精度の低いもっと簡単なキャッセル教授の言葉を使えば、一年間のポンド数である。・・ある年に蓄えられた資本量はその年の 「貯蓄量」と必然的に等しいという一般的な考え方には要注意だ。これは正しくない。たとえ、他人の消費を増やすために貸し出される貯蓄を除外して、貯蓄を 純貯蓄に限るとしても、また、未使用の用役に対する権利を銀行貨幣の形で一時的に蓄えたものを除外するとしても、そうである。なぜなら、資本になるはずの 多くの貯蓄は実際には無駄な用途に誤用されて、資本になれずに終わるからである[7]。」

  Professor Pigou's only significant reference to what determines the rate of interest is, I think, to be found in his Industrial Fluctuations (1st edn.), pp. 251-3, where he controverts(反駁する) the view that the rate of interest, being determined by the general conditions of demand and supply of real capital ' lies outside the central or any other bank's control. Against this view he argues that: “When bankers create more credit for business men, they make, in their interest, subject to the explanations given in chapter xiii. of part i.,[8] a forced levy of real things from the public, thus increasing the stream of real capital available for them, and causing a fall in the real rate of interest on long and short loans alike. It is true, in short, that the bankers' rate for money is bound by a mechanical tie to the real rate of interest on long loans; but it is not true that this real rate is determined by conditions wholly outside bankers' control.”

  何が利子率を決めるかについてのピグー教授の唯一の明確な言及は、教授の『産業変動論』(初版)の251~3頁に見つけることが出来ると思われる。そこで 彼は「利子率は現物資本の需要と供給の一般的条件によって決まるので中央銀行だろうがどの銀行だろうが利子率をコントロールすることは出来ない」とする考 え方を否定している。この考え方に対して彼は言っている。「銀行家が実業家のために信用創造を増加すると、銀行家は、第1部第13章[8]の説明どおり、 実業家のために、社会から実物を強制徴収(=信用創造による物価上昇で実業家の資産価値が上がる)して、実業家が使える実物資本の流れを増やして、長期と 短期の双方のローンの利子率を下げてやるのである。要するに、銀行家の利子率が長期ローンの実質利子率に機械的に縛られるというのは事実だが、この実質利 子率が銀行家の手の届かないところで決まっているというのは事実ではないのである。」

  My running comments on the above have been made in the footnotes. The perplexity which I find in Marshall's account of the matter is fundamentally due, I think, to the incursion of the concept “interest”, which belongs to a monetary economy, into a treatise which takes no account of money. “Interest” has really no business to turn up at all in Marshall's Principles of Economics, ― it belongs to another branch of the subject. Professor Pigou, conformably with his other tacit assumptions, leads us (in his Economics of Welfare) to infer that the unit of waiting is the same as the unit of current investment and that the reward of waiting is quasi-rent, and practically never mentions interest, ― which is as it should be. Nevertheless these writers are not dealing with a non-monetary economy (if there is such a thing). They quite clearly presume that money is used and that there is a banking system. Moreover, the rate of interest scarcely plays a larger part in Professor Pigou's Industrial Fluctuations (which is mainly a study of fluctuations in the marginal efficiency of capital) or in his Theory of Unemployment (which is mainly a study of what determines changes in the volume of employment, assuming that there is no involuntary unemployment) than in his Economics of Welfare.

  上記に引用についての私の見解は注釈に含めた。利子率についてのマーシャルの記述の中で私が見出した混乱の原因は、根本的には、貨幣経済に属する「利子 率」という概念を、貨幣を扱わない書物の中に持ち込んだことにあると思われる。実際には「利子率」はマーシャルの『経済原理』の中には登場する必要はない である。―利子率は経済のもう一つの枝に属するからである。ピグー教授は、彼自身の別の暗黙の想定に満足して、(『厚生経済学』において)待忍の単位は現 行投資の単位と同じものであり、待忍の報酬は準地代(=資本からの所得、地代に似ているからこういう)であると我々に思わせようとして、利子率のことには 実質上一切言及していない。―しかもそれが正しいのである。にも関わらず、この二人は貨幣のない社会(もしそんな社会があればだが)を扱っているのではな く、貨幣の使用と銀行の存在を明らかに前提にしているのである。さらに言えば、ピグー教授の『産業変動論』(主に資本の限界効率の変動の研究をしている) でも『失業論』(主に雇用量の変化を決めるものについての研究で、非自発的失業が存在しないことを前提にしている)でも『厚生経済学』と同じくほとんど利 子率は登場しないのである(=no more...thanの構文)。

II

  The following from his Principles of Political Economy (p.511) puts the substance of Ricardo's theory' of the Rate of Interest:

第2節

 リカードの『経済学原理』(511頁)の次の引用の中に、リカードの利子率理論の本質が表れている。

“The interest of money is not regulated by the rate at which the Bank will lend, whether it be 5, 3 or 2 per cent, but by the rate of profit which can be made by the employment of capital, and which is total independent of the quantity or of the value of money. Whether the Bank lent one million, ten millions, or a hundred millions, they would not permanently alter the market rate of interest; they would alter only the value of the money which they thus issued. In one case, ten or twenty times more money might be required to carry on the same business than what might be required in the other. The applications to the Bank for money, then, depend on the comparison between the rate of profits that may he made by the employment of it, and the rate at which they are willing to lend it. If they charge less than the market rate of interest, there is no amount of money which they might not lend; ― if they charge more than that rate, none but spendthrifts and prodigals would be found to borrow of them.”

「利子を決めるのは、銀行が金を貸し出す利率(5%,3%,2%のいずれであっても)ではなく、資本の利用によって生まれる利益の比率であって、それは貨 幣量や貨幣価値とは何の関係もない。銀行が百万貸そうが、1千万貸そうが、1億貸そうが、それで市場利子率が長期的に変わるわけではない。単に自分たちの 発行した貨幣の価値が変わるだけである。同じ事業を行うのにも、ある場合(=貨幣価値が落ちた場合)には、他の場合に必要だったのと比べて十倍か二十倍も 多くの貨幣が必要となるかもしれない。だから、銀行に対する借金の申し込みは、その金で生み出される利益率と銀行が貸し出す利子率を天秤にかけて行うこと になる。もし銀行が市場利子率より低い利子を課すなら、銀行はどんな額でも貸出しできるだろう。しかし、もし銀行が市場利子率より高い利子を課すなら、浪 費家か道楽者しか借手は見つからないだろう。」

  This is so clear-cut that it affords a better starting-point for a discussion than the phrases of later writers who, without really departing from the essence of the Ricardian doctrine, are nevertheless sufficiently uncomfortable about it to seek refuge in haziness. The above is, of course, as always with Ricardo, to be interpreted as a long-period doctrine, with the emphasis on the word “permanently” half-way through the passage; and it is interesting to consider the assumptions required to validate it.

 この文章は極めて明確なので、後世の学者の文章よりは議論の出発点にするのに相応しい。後世の学者たちはリカードの説の本質から決して離れることがない のに、リカードの説に居心地の悪さを感じてうやむやにして逃げているのである。もちろんこの文章はリカードのいつもの例に漏れず、長期の理論であると解釈 すべきであって、文章の真ん中の「長期的に」を強調して読まねばならない。そして、この説が正しいと認めるために必要な前提を考えることは興味深い。

  Once again the assumption required is the usual classical assumption, that there is always full employment; so that, assuming no change in the supply curve of labour in terms of product, there is only one possible level of employment in long-period equilibrium. On this assumption with the usual ceteris paribus, i.e. no change in psychological propensities and expectations other than those arising out of a change in the quantity of money, the Ricardian theory is valid, in the sense that on these suppositions there is only one rate of interest which will be compatible with full employment in the long period. Ricardo and his successors overlook the fact that even in the long period the volume of employment is not necessarily full but is capable of varying, and that to every banking policy there corresponds a different long-period level of employment; so that there are a number of positions of long-period equilibrium corresponding to different conceivable interest policies on the part of the monetary authority.

  ここで必要とされている前提はいつもの古典派の前提、つまり「常に完全雇用であること」である。つまり、生産物で測った労働の供給曲線に変化がないと想定 するとき、長期均衡で可能な雇用水準はただ一つである。これを前提として、他の条件が同じで、心理的な性向も期待の変化も貨幣量の変化から由来するもの以 外はいかなる変化も起こらないとするなら、リカードの説は有効である。それはこの前提のもとで長期における完全雇用と両立する利子率は一つしかないという 意味である。リカードとその後継者たちは、たとえ長期でも雇用量は必ずしも完全状態ではなく変化する可能性があるし、銀行の方針が変わればそれに応じて長 期の雇用水準も様々に変化するという事実を見逃しているのである。つまり、貨幣当局の金利政策が変わればそれに対応する長期の均衡状態の位置も沢山存在す るのである。

  If Ricardo had been content to present his argument solely as applying to any given quantity of money created by the monetary authority, it would still have been correct on the assumption of flexible money-wages. If, that is to say, Ricardo had argued that it would make no permanent alteration to the rate of interest whether the quantity of money was fixed by the monetary authority at ten millions or at a hundred millions, his conclusion would hold. But if by the policy of the monetary authority we mean the terms on which it will increase or decrease the quantity of money. i.e. the rate of interest at which it will, either by a change in the volume of discounts or by open-market operations, increase or decrease its assets ― which is what Ricardo expressly does mean in the above quotation ― then it is not the case either that the policy of the monetary authority is nugatory or that only one policy is compatible with long-period equilibrium; though in the extreme case where money-wages are assumed to fall without limit in face of involuntary unemployment through a futile competition for employment between the unemployed labourers, there will, it is true, be only two possible long-period positions ― full employment and the level of employment corresponding to the rate of interest at which liquidity-preference becomes absolute (in the event of this being less than full employment.). Assuming flexible money-wages, the quantity of money as such is, indeed, nugatory in the long period; but the terms on which the monetary authority will change the quantity of money enters as a real determinant into the economic scheme.

  もしリカードが自分の理論は貨幣当局が創造した一定の貨幣量に対してのみ当てはまるものであることで満足なら、貨幣賃金が変化する想定でも彼の理論は有効 だろう。つまり、もしリカードが、貨幣量が貨幣当局によって固定されている場合には、それが1千万だろうが1億だろうが、利子率は長期的に変化がないと言 うなら、彼の結論は有効である。しかし、貨幣当局の方針が、貨幣量を増減させるための条件、即ち当局が割引額の変更や公開市場操作によってその資産を増減 させる利子率を意味するなら(これは上記の引用でリカードがまさに強調している点である)、貨幣当局の政策は無効ではないし、長期の均衡と両立する政策 (=利子率)は一つしかないわけでもない。ただし、失業労働者間の雇用をめぐる些細な競争のせいで非自発的失業が発生して、貨幣賃金が無制限に下ると思わ れる極端なケースでは、確かに長期の均衡位置は二つだけになる。それは、一つは完全雇用であるが、もう一つは流動性選好が絶対的になったとき(この場合は 完全雇用に達していない)の利子率に対応する雇用水準である。貨幣賃金が変化する想定では、貨幣量はそれだけでは長期的には効果がない。そうではなく、貨 幣当局が貨幣量を変更する条件(=利子率)こそが真の決定要因として経済スキームの中に入ってくるのである。

  It is worth adding that the concluding sentences of the quotation suggest that Ricardo was overlooking the possible changes in the marginal efficiency of capital according to the amount invested. But this again can be interpreted as another example of his greater internal consistency compared with his successors. For if the quantity of employment and the psychological propensities of the community are taken as given, there is in fact only one possible rate of accumulation of capital and, consequently, only one possible value for the marginal efficiency of capital. Ricardo offers us the supreme intellectual achievement, unattainable by weaker spirits, of adopting a hypothetical world remote from experience as though it were the world of experience and then living in it consistently. With most of his successors common sense cannot help breaking in ― with injury to their logical consistency.

  もうひとつ付け加えると、引用文の結論部分でリカードは投資量に応じた資本の限界効率の変化の可能性を見逃している。しかし、この事実はリカードが彼の後 継者と比べて内的一貫性を維持していたことの例として見ることが出来る。というのは、もし雇用量と社会の心理傾向を所与とするなら、可能な資本の蓄積量は ただ一つであり、その結果として、可能な資本の限界効率もただ一つだからである。リカードは経験から離れた仮想的世界をまるで経験世界であるかのよう取り 上げて、そこで首尾一貫して生き抜くという、軟弱な精神では到底達成できない最高に知的な偉業を我々に残したのである。彼の後継者たちの場合はどうしても 常識が割り込んできて、論理的な一貫性が損なわれることになるのである。

III

  A peculiar theory of the rate of interest has been propounded by Professor von Mises and adopted from him by Professor Hayek and also, I think, by Professor Robbins; namely, that changes in the rate of interest can be identified with changes in the relative price levels of consumption-goods and capital-goods.[9] It is not clear how this conclusion is reached. But the argument seems to run as follows. By a somewhat drastic simplification the marginal efficiency of capital is taken as measured by the ratio of the supply price of new consumers' goods to the supply price of new producers' goods.[10] This is then identified with the rate of interest. The fact is called to notice that a fall in the rate of interest is favourable to investment. Ergo, a fall in the ratio of the price of consumers' goods to the price of producers' goods is favourable to investment.

第3節

  奇抜な利子率論を展開したのはフォン・ミーゼス教授で、その理論はハイエク教授とロビン教授に採用されている。その理論とは、利子率の変化は、消費財と資 本財の相対的価格水準の変化と一致するとするものである[9]。どうしてこんな結論になったのかは明らかではない。議論は次のように進む。いくらか斬新な 単純化によって、資本の限界効率は新たな消費財の供給価格と新たな生産財の供給価格の比率によって測ることが出来る[10]。すると、これは利子率と一致 する。この事実は、利子率の下落が投資に有利であることを教えている。したがって、消費財の価格と生産財の価格の比率の低下は投資に有利である。

  By this means a link is established between increased saving by an individual and increased aggregate investment. For it is common ground that increased individual saving will cause a fall in the price of consumers' goods, and, quite possibly, a greater fall than in the price of producers' goods, hence, according to the above reasoning, it means a reduction in the rate of interest which will stimulate investment. But, of course, a lowering of the marginal efficiency of particular capital assets, and hence a lowering of the schedule of the marginal efficiency of capital in general, has exactly the opposite effect to what the argument assumes. For investment is stimulated either by a raising of the schedule of the marginal efficiency or by a lowering of the rate of interest. As a result of confusing the marginal efficiency of capital with the rate of interest, Professor von Mises and his disciples have got their conclusions exactly the wrong way round.

  この手段によって個人の貯蓄の増加と総投資の増加の間に結びつきが生まれる。というのは、個人の貯蓄の増加は消費財の価格の低下を引き起こし、さらに生産 財の価格のさらに大きな低下を引き起こす可能性が極めて高く、それは上記の理屈では利子率の低下を意味し投資を刺激する。しかし、当然、特定の資本資産の 限界効率が低下して、一般に資本の限界効率表が下がることは、この理論の想定とは正反対の降下を持っている。というのは、
投資は資本の限界効率表を引き上げるか利子率が低下することで刺激されるからである。資本の限界効率と利子率のを混同した結果、ミーゼス教授と彼の弟子たちは結論で間違った方向に進んでしまったのである。

A good example of a confusion along these lines is given by the following passage by Professor Alvin Hansen: [11] “It has been suggested by some economists that the net effect of reduced spending will be a lower price level of consumers' goods than would otherwise have been the case, and that, in consequence, the stimulus to investment in fixed capital would thereby tend to be minimized. This view is, however, incorrect and is based on a confusion of the effect on capital formation of (1) higher or lower prices of consumers' goods, and (2) a change in the rate of interest. It is true that in consequence of the decreased spending and increased saving, consumers' prices would be low relative to the prices of producers' goods. But this, in effect, means a lower rate of interest, and a lower rate of interest stimulates an expansion of capital investment in fields which at higher rates would be unprofitable.”

この混乱の明らかな例は、アルヴィン・ハンセン教授の次の文章に表れている[11]。「経済学者の中には、支出の減少の効果は、そうでない場合よりも消費 財の価格水準が大きく低下することであり、その結果、固定資本の投資に対する刺激が小さくなってしまうと考える人がいるが、この考え方は間違っている。消 費財の価格の上昇(1)と下降の資本形成に対する影響と、利子率の変化(2)の影響を混同しているのである。支出の減少と貯蓄の増加の結果として、消費者 物価は生産財価格と比べて低下するのは事実であるが、これは実際には利子率の低下を意味しており、利子率の低下は高い利子率では不利な分野への資本投資の 拡大を引き起こすのである。」

Author's Footnotes

[1]. It is to be noticed that Marshall uses the word “capital” not “money” and the word “stock” not “loans”; interest is a payment for borrowing money, and “demand for capital” in this context should mean “demand for loans of money for the purpose of buying a stock of capital-goods”. But the equality between the stock of capital-goods offered and the stock demanded will be brought about by the prices of capital-goods, not by the rate of interest. It is equality between the demand and supply of loans of money, i.e. of debts, which is brought about by the rate of interest.

[2]. This assumes that income is not constant. But it is not obvious in what way a rise in the rate of interest will lead to “extra work”. Is the suggestion that a rise in the rate of interest is to be regarded, by reason of its increasing the attractiveness of working in order to save, as constituting a sort of increase in real wages which will induce the factors of production to work for a lower wage? This is, I think, in Mr. D. H. Robertson's mind in a similar context. Certainly this “would not quickly amount to much”; and an attempt to explain the actual fluctuations in the amount of investment by means of this factor would be most unplausible, indeed absurd. My rewriting of the latter half of this sentence would be: “and if an extensive increase in the demand for capital in general, due to an increase in the schedule of the marginal efficiency of capital, is not offset by a rise in the rate of interest, the extra employment and the higher level of income, which will ensue as a result of the increased production of capital-goods, will lead to an amount of extra waiting which in terms of money will be exactly equal to the value of the current increment of capital-goods and will, therefore, precisely provide for it.”

[3]. Why not by a rise in the supply price of capital-goods? Suppose, for example, that the “extensive increase in the demand for capital in general” is due to a fall in the rate of interest. I would suggest that the sentence should be rewritten: “In so far, therefore, as the extensive increase in the demand for capital-goods cannot be immediately met by an increase in the total stock, it will have to be held in check for the time being by a rise in the supply price of capital-goods sufficient to keep the marginal efficiency of capital in equilibrium with the rate of interest without there being any material change in the scale of investment; meanwhile (as always) the factors of production adapted for the output of capital-goods will be used in producing those capital-goods of which the marginal efficiency is greatest in the new conditions.”

[4]. In fact we cannot speak of it at all. We can only properly speak of the rate of interest on money borrowed for the purpose of purchasing investments of capital, new or old (or for any other purpose).

[5]. Here the wording is ambiguous as to whether we are to infer that the postponement of consumption necessarily has this effect, or whether it merely releases resources which are then either unemployed or used for investment according to circumstances.

[6]. Not, be it noted, the amount of money which the recipient of income might, but does not, spend on consumption; so that the reward of waiting is not interest but quasi-rent. This sentence seems to imply that the released resources are necessarily used. For what is the reward of waiting if the released sources are left unemployed?

[7]. We are not told in this passage whether net savings would or would not be equal to the increment of capital, if we were to ignore misdirected investment but were to take account of “temporary accumulations of unused claims upon services in the form of bank-money”. But in Industrial Fluctuations (p. 22) Prof. Pigou makes it clear that such accumulations have no effect on what he calls “real savings”.

[8]. This reference (op. cit. pp. 129-134) contains Prof. Pigou's view as to the amount by which a new credit creation by the banks increases the stream of real capital available for entrepreneurs. In effect he attempts to deduct “from the floating credit handed over to business men through credit creations the floating capital which would have been contributed in other ways if the banks had not been there”. After these deductions have been made, the argument is one of deep obscurity. To begin with, the rentiers have an income of 1500, of which they consume 500 and save 1000; the act of credit creation reduces their income to 1300, of which they consume 500 - x and save 800 + x; and x, Prof. Pigou concludes, represents the net increase of capital made available by the act of credit creation. Is the entrepreneurs' income supposed to be swollen by the amount which they borrow from the banks (after making the above deductions)? Or is it swollen by the amount, i.e. 200, by which the rentiers' income is reduced? In either case, are they supposed to save the whole of it? Is the increased investment equal to the credit creations minus the deductions? Or is it equal to x? The argument seems to stop just where it should begin.

[9]. The Theory of Money and Credit, p. 339 et passim, particularly p. 363.

[10]. If we are in long-period equilibrium, special assumptions might be devised on which this could be justified. But when the prices in question are the prices prevailing in slump conditions, the simplification of supposing that the entrepreneur will, in forming his expectations, assume these prices to be permanent, is certain to be misleading. Moreover, if he does, the prices of the existing stock of producers' goods will fall in the same proportion as the prices of consumers' goods.

[11]. Economic Reconstruction, p. 233.

著者注

[1] 注意すべきことは、マーシャルはここで「貨幣」の代わりに「資本」という言葉を使い、「融資」の代わりに「ストック」という言葉を使っていること である(=この文章は前の単語に置き換えて読め)。利子は貨幣を借りたことに対する対価であり、この文脈での「資本需要」とは「資本財ストックを購入する 目的で貨幣を融資する需要」を意味する。しかし、資本財ストックの供給と需要の一致は、利子率ではなく資本財の価格によってもたらされる。利子率によって もたらされるのは、貨幣融資(つまり債権)の需要と供給の一致なのである。

[2] これは所得を一定と想定していないことになる。しかし、利子率の上昇がどうやって「労働の増加」になるのか明らかでない。この意味は、利子率が上 昇すると、貯蓄のために働く魅力が増えることで、実質賃金が上昇するのと同じ効果を持つと見做せるので、生産要素はもっと低い賃金で働く気になるというこ とだろうか? これが同じ文脈でD.H.ロバートソン氏の考えであると思われる。確かに、労働の増加は「急に大きな量になることはない」。確かに、この要 素によって実際の投資量の変化を説明するのは非現実的であるどころか馬鹿げている。この文章の後半を私が書き直すと、「そしてもし資本の限界効率表の上昇 に起因する一般的な資本需要の大幅な増加が利子率の上昇によって相殺されなかったら、資本財の生産増加の結果として発生する雇用の増加と所得水準の上昇が 待忍の増加をもたらす。この待忍の増加は貨幣で測ると資本財の当期の増加と丁度一致する。つまり、待忍の増加がまさに資本財の増加をもたらすのである。」

[3] なぜ資本財の供給の増加ではないのか? 例えば、仮に「一般的な資本需要の大幅な増加」が利子率の下落によって起こるとするなら、この文章は次の ように書き直すのがよいと思う。「したがって、資本需要の大幅な増加が総ストックの増加によって直ちに満たされない場合には、資本需要の増加は当面は資本 財の供給価格の増加によって食い止めるしかないだろう。そうして投資規模の実質的な変化が起きないままで、資本の限界効率と利子率の均衡を保つのである。 その間に(いつものように)資本財の産出に適合した生産要素が、限界効率が新たな条件下で最大となるような資本財を生産するために使われるのである。」

[4] 実際には我々はこんな言い方は決してしない。利子率は借りた貨幣についてのみ正しく言うことが出来るもので、その目的が資本の投資物件の購入であれ何であれ構わないし、投資物件が新しくても古くてもよいのである。

[5] 消費の延期は必然的にこの効果を持つと推定すべきなのか、それとも、消費の延期は利用されない資源を単に状況に応じて投資に解放するということなのか、この言葉遣いでは明確ではない。

[6] これは所得の受領者が消費に使えるが使わない貨幣の量でないことに注意。だから、待忍の報酬は利子ではなく準地代であるとなっている。この文章の 意味は、解放された資源は必然的に使用されるかのようである。というのは、もし解放された資源が利用されずに放置されたら、待忍の報酬はどこからも来ない からである。

[7] もし誤用された投資を無視して「未使用の用役に対する権利を銀行貨幣の形で一時的に蓄えたもの」を考慮に入れたら、純貯蓄は資本の増加に等しくなるのかど うかはこの文章からは分からない。しかし、『産業変動論』(22頁)ではピグー教授は、そのように蓄えたものは「実質貯蓄」と彼が呼ぶものには何の影響も 与えないと言っている。

[8] この参照箇所(前掲書129~134頁)には、銀行家による新たな信用創造によって企業家にとって利用可能となる実物資本の流れがどれだけ増える かについて、ピグー教授が見解を述べている。要するに、教授は「信用創造によって実業家に渡される一時的信用から、銀行がなくても他の方法で供給されたは ずの一時的資本」を差し引こうとするのである。この控除の後の議論がよくわからない。まず、利子生活者は1500の所得を得る。そのうち500を消費して 1000を貯蓄する。信用創造行為は彼らの所得を1300に減らす(=200が強制徴収、インフレによる損失)。そのうち500-xを消費し800+xを 貯蓄する。ピグー教授が言うには、このxが信用創造行為によって利用可能となった資本の純増加分である。では、企業家の所得は銀行からの借金によって増え るというのだろうか。それとも、利子生活者の所得が減った200だけ企業家の所得は(上記の控除後でも)増えるのだろうか。どちらにしても、利子生活者は その全額を貯蓄するというのだろうか。投資の増加は信用創造から控除を引いた分に等しいのだろうか。あるいは、投資の増加はxと等しいのだろうか。議論は まさに始まるところで終わっているのである。

[9] 『貨幣と信用の理論』339頁以下、特に369頁。

[10] もし長期の均衡状態にあるなら、資本の限界効率をこのように測定する方法を正当化するために特別な想定を工夫することは出来る。しかし、この二 つの供給価格が不況時の市場価格である時、企業家は予想を立てる際にこの値段を長期的なものと考えると単純に想定するのは、明らかに間違いである。その 上、もし企業家がそう考えるなら、生産財の現存ストックの価格は消費財の価格と同じ割合で下落してしまうだろう。

[11] 「経済再建』233頁
 

Chapter 15. The Psychological and Business Incentives To Liquidity
第15章 流動性に対する心理的と経営的誘引
I

  WE must now develop in more detail the analysis of the motives to liquidity-preference which were introduced in a preliminary way in Chapter 13. The subject is substantially the same as that which has been sometimes discussed under the heading of the Demand for Money(貨幣需要). It is also closely connected with what is called the income-velocity(流通速度) of money; ― for the income-velocity of money merely measures what proportion of their incomes the public chooses to hold in cash, so that an increased income-velocity of money may be a symptom of a decreased liquidity-preference. It is not the same thing, however, since it is in respect of his stock of accumulated savings, rather than of his income, that the individual can exercise his choice between liquidity and illiquidity. And, anyhow, the term “income-velocity of money” carries with it the misleading suggestion of a presumption in favour of the demand for money as a whole being proportional, or having some determinate relation, to income, whereas this presumption should apply, as we shall see, only to a portion of the public's cash holdings; with the result that it overlooks the part played by the rate of interest.

第1節
  いまや我々は第13章で予備的に導入した流動性選好の動機の分析をさらに詳細に発展させる時である。このテーマは貨幣需要という見出しのもとで議論されて きたものと本質的には同じである。また貨幣の所得速度と呼ばれているものと密接に結びついている。― というのは貨幣の所得速度は、単に社会が所得のどの割合を現金で保有しようとしているかを表しているが、貨幣の所得速度が上がることは流動性選好が減少す ることの表すからである。しかしながら、両者は同じものではない。なぜなら、個人が流動性(=現金)と非流動性(=債権)のどちらを選ぶかは、所得との関 係ではなく、自分の貯蓄ストックとの関係で選ぶからである。さらに、とにかく「貨幣の所得速度」という言い方は、貨幣需要が全体として所得に比例している か、あるいは貨幣需要が所得と明確な関係にあると誤解されやすい。実際にはこの表現は、これから見るように、社会の現金保有の一部についてのみ当てはまる だけである。その結果、貨幣需要に対して利子率の果たす役割を見逃していることになる。

  In my Treatise on Money I studied the total demand for money under the headings of income-deposits, business-deposits, and savings-deposits, and I need not repeat here the analysis which I gave in Chapter 3 of that book. Money held for each of the three purposes forms, nevertheless, a single pool, which the holder is under no necessity to segregate into three water-tight compartments; for they need not be sharply divided even in his own mind, and the same sum can be held primarily for one purpose and secondarily for another. Thus we can ― equally well, and, perhaps, better ― consider the individual's aggregate demand for money in given circumstances as a single decision, though the composite result of a number of different motives.

  自著『貨幣論』で私は貨幣需要の全体について、所得預金、営業預金、貯蓄預金という項目に分けて研究した。その本の第3章で行った分析をここで繰り返す必 要はない。ただし、この三つの目的のそれぞれのために保有された貨幣は一つのプールを形成しており、保有者はこの三つの区切りを厳密に区別する必要はまっ たくないのである。この三つの目的は人々の頭の中ではっきり分かれている必要もない。同じ金額の保有が主に一つ目の目的で副次的にもう一つの目的であって も構わない。つまり、元々は別の動機から来ているとしても、所与の環境における個人の貨幣需要の全体を一つの決断と見なすことが出来るし、その方がうまく いくのである。

  In analysing the motives, however, it is still convenient to classify them under certain headings, the first of which broadly corresponds to the former classification of income-deposits and business-deposits, and the two latter to that of savings-deposits. These I have briefly introduced in Chapter 13 under the headings of the transactions-motive, which can be further classified as the income-motive and the business-motive, the precautionary-motive and the speculative-motive.

 しかし、動機を分析する場合には、やはりしかるべき項目に分類する方が便利である。その一つめは、以前の分類の所得預金と営業預金に対応するもので、あ との二つは貯蓄預金に相当する。これらは第十三章で簡単に触れておいたもので、取引動機(ここでは所得動機と営業動機に相当する)と予備的動機と投機的動 機である。

(i) The Income-motive. ― One reason for holding cash is to bridge the interval between the receipt of income and its disbursement. The strength of this motive in inducing a decision to hold a given aggregate of cash will chiefly depend on the amount of income and the normal length of the interval between its receipt and its disbursement. It is in this connection that the concept of the income-velocity of money is strictly appropriate.

(一)所得動機―現金保有の一つの理由は、所得の受取と支出の間を橋渡しをすることである。一定の現金全部を保有する気になるこの動機の強さは、主に所得 量および所得の受取と支出の通常の間隔に依存する。これとの関連では、まさに貨幣の所得速度という概念が厳密に当てはまる。

(ii) The Business-motive. ― Similarly, cash is held to bridge the interval between the time of incurring business costs and that of the receipt of the sale-proceeds; cash held by dealers to bridge the interval between purchase and realization being included under this heading. The strength of this demand will chiefly depend on the value of current output (and hence on current income), and on the number of hands through which output passes.

(二)営業動機―同様に、現金保有は営業経費の支払時期と販売売上の受取時期の間を橋渡しをする。商売人は仕入れと販売の橋渡しをするために現金を保有す るが、これもこの項目に含まれる。この需要の強さは、主に当期の産出物の価格(したがって現行の所得)とその産出物が通過する人手の数に依存する。

(iii) The Precautionary-motive. ― To provide for contingencies requiring sudden expenditure and for unforeseen opportunities of advantageous purchases, and also to hold an asset of which the value is fixed in terms of money to meet a subsequent liability fixed in terms of money, are further motives for holding cash.

(三)予備的動機―急な出費を要する不慮の事態と、有利な買い物をする予期せぬ機会に備えること、および、貨幣で測った債務(=保険や年金など)を果たすために貨幣価値が固定した資産(=預金)を持つことも、現金を持つ動機である。

The strength of all these three types of motive will partly depend on the cheapness and the reliability of methods of obtaining cash, when it is required, by some form of temporary borrowing, in particular by overdraft(当座貸越) or its equivalent. For there is no necessity to hold idle cash to bridge over intervals if it can be obtained without difficulty at the moment when it is actually required. Their strength will also depend on what we may term the relative cost of holding cash. If the cash can only be retained by forgoing the purchase of a profitable asset, this increases the cost and thus weakens the motive towards holding a given amount of cash. If deposit interest is earned or if bank charges are avoided by holding cash, this decreases the cost and strengthens the motive. It may be, however, that this is likely to be a minor factor except where large changes in the cost of holding cash are in question.

この三つのタイプの動機の強さは、必要な時に現金を手に入れる手段、つまり何らかの一時的借り入れ、特に当座貸越のような手段が安価で信頼性のあることに 依存している。というのは、現金が必要な時に難なく手に入るなら、間隔を埋めるために無駄な現金を手元に置く必要はないからである。またこの三つの動機の 強さは、現金保有の相対的コスト(=機会費用)とでも呼べるものに依存する。つまり、もし有利な資産の買い入れをやめることでしか現金が保持できないな ら、現金保持のコスト(=機会費用)が増えるので、一定量の現金を保有する動機は弱くなる。もし預金金利が稼げるかあるいは現金保有によって銀行の手数料 を回避できるなら、現金保有のコストは下がるので動機は強まる。しかしながら、現金保有のコストの大きな変化が問題となる場合を除いては、このコストは小 さい要因であると言っていい。

(iv) There remains the Speculative-motive. ― This needs a more detailed examination than the others, both because it is less well understood and because it is particularly important in transmitting the effects of a change in the quantity of money.

(四)最後に投機的動機―これについては他の動機より詳細な検討が必要である。というのは、この動機はあまりよく理解されていないし、貨幣量の変化の影響を伝えるのに特に大切だからである。

  In normal circumstances the amount of money required to satisfy the transactions-motive and the precautionary-motive is mainly a resultant of the general activity of the economic system and of the level of money-income. But it is by playing on the speculative-motive that monetary management (or, in the absence of management, chance changes in the quantity of money) is brought to bear on the economic system. For the demand for money to satisfy the former motives is generally irresponsive to any influence except the actual occurrence of a change in the general economic activity and the level of incomes; whereas experience indicates that the aggregate demand for money to satisfy the speculative-motive usually shows a continuous response to gradual changes in the rate of interest, i.e. there is a continuous curve relating changes in the demand for money to satisfy the speculative motive and changes in the rate of interest as given by changes in the prices of bonds and debts of various maturities.

  普通の状況では、取引動機と予備的動機を満たすための貨幣需要は、おもに一般的な経済活動の結果として、また貨幣による所得水準の結果として発生する。し かし、貨幣政策(政策がない場合には貨幣量の偶然の変化)の経済に対する働きかけは、投機的動機に対する働きかけとして行われる。というのは、取引動機と 予備的動機を満たすための貨幣需要が影響を受けるのは、一般的な経済活動と所得水準の現実の変化だけで、一般的にそれ以外から影響を受けることはない。一 方、経験が教えるところでは、投機的動機を満たすための総貨幣需要はふつう利子率の段階的な変化に連続的に影響を受ける。つまり、投機的動機を満たすため の貨幣需要の変化と、様々な満期の債券価格の変化に表れる利子率の変化を結びつける連続的な曲線が存在するのである。

  Indeed, if this were not so, “open market operations” would be impracticable. I have said that experience indicates the continuous relationship stated above, because in normal circumstances the banking system is in fact always able to purchase (or sell) bonds in exchange for cash by bidding the price of bonds up (or down) in the market by a modest amount; and the larger the quantity of cash which they seek to create (or cancel)(貨幣創造とその逆) by purchasing (or selling) bonds and debts, the greater must be the fall (or rise) in the rate of interest. Where, however, (as in the United States, 1933-1934) open-market operations have been limited to the purchase of very short-dated securities, the effect may, of course, be mainly confined to the very short-term rate of interest and have but little reaction on the much more important long-term rates of interest.

  実際、もしそうでなかったら「公開市場操作」などは実行不可能である。私が言ったように、経験が教えるところでは貨幣需要と利子率の間には連続的関係が存 在する。なぜなら、普通の状況では、銀行は常に市場で債券価格をせり上げ(下げ)て現金と交換に債券を適度に購入(売払)することが出来るからである。そ して、銀行が債券と債権を買う(売る)ことで創造(回収)しようとする現金の量が多ければ多いほど、利子率の下降(上昇)は大きくなる。しかしながら、 (1933年から1934年の合衆国のように)公開市場操作が非常に単期日の証券の購入に限られている場合には、もちろん、その効果は非常に短期の利子率 に限定されるし、もっと重要な長期の利子率に対してはたいした作用を与えない。

  In dealing with the speculative-motive it is, however, important to distinguish between the changes in the rate of interest which are due to changes in the supply of money available to satisfy the speculative-motive, without there having been any change in the liquidity function, and those which are primarily due to changes in expectation affecting the liquidity function itself. Open-market operations may, indeed, influence the rate of interest through both channels; since they may not only change the volume of money, but may also give rise to changed expectations concerning the future policy of the Central Bank or of the Government. Changes in the liquidity function itself, due to a change in the news(情勢の変化) which causes revision of expectations, will often be discontinuous, and will, therefore, give rise to a corresponding discontinuity of change in the rate of interest. Only, indeed, in so far as the change in the news is differently interpreted by different individuals or affects individual interests differently will there be room for any increased activity of dealing in the bond market. If the change in the news affects the judgment and the requirements of everyone in precisely the same way, the rate of interest (as indicated by the prices of bonds and debts) will be adjusted forthwith to the new situation without any market transactions being necessary.

  しかしながら、投機的動機を扱うにあたって重要なのは、利子率の変化のうちでも、流動性関数が不変な状態で投機的動機を満たすために利用可能な「貨幣供給 の変化から来る利子率の変化」と、流動性関数そのものに影響を与える「予想の変化から来る利子率の変化」とを区別することである。確かに、公開市場操作は この二つのルートから利子率に影響を与える。というのは、公開市場操作は貨幣量を変えるだけではなく、中央銀行や政府の将来の方針についての予想にも変化 をもたらすからである。<しかし、>予想の変化は情勢の変化によってもたらされ、情勢の変化が流動性関数の変化をもたらすが、その変化はしばしば非連続で あり、したがって、それに対応する利子率の変化も非連続なのである。実際、情勢の変化が人によって異なって解釈をされ、人々の利害に与える影響も異なって いる場合のみ、債券市場の取引活動が増える可能性があるのだ。もし情勢の変化が全員の判断と要求とに全く同じように影響するなら、利子率(債券と債権に表 れる)は市場取引を全く必要とせずに即座に新たな状況に適応するだろう。

  Thus, in the simplest case, where everyone is similar and similarly placed, a change in circumstances or expectations will not be capable of causing any displacement of money whatever; ― it will simply change the rate of interest in whatever degree is necessary to offset the desire of each individual, felt at the previous rate, to change his holding of cash in response to the new circumstances or expectations; and, since everyone will change his ideas as to the rate which would induce him to alter his holdings of cash in the same degree, no transactions will result. To each set of circumstances and expectations there will correspond an appropriate rate of interest, and there will never be any question of anyone changing his usual holdings of cash.

 つまり、全員が似ていて似たような立場であるという最も単純なケースでは、環境の変化や予想の変化は貨幣の移動を全く引き起こすことはなく、単に利子率 の変化をもたらすだけである。そして、その変化によって、元の利子率の時に新しい環境や予想に対応して現金保有量を変えたいと感じた気持ちは消えてしまう のである。そして、前なら現金保有量を変えたくなった利子率についての全員の考えも一斉に変わってしまうので、どんな取引も発生しないのである。それぞれ の環境と予想に対して適当な利子率が対応するなら、人は誰も自分のいつもの現金保有量を変えようとはしないのである。

  In general, however, a change in circumstances or expectations will cause some realignment in individual holdings of money; ― since, in fact, a change will influence the ideas of different individuals differently by reason partly of differences in environment and the reason for which money is held and partly of differences in knowledge and interpretation of the new situation. Thus the new equilibrium rate of interest will be associated with a redistribution of money-holdings. Nevertheless it is the change in the rate of interest, rather than the redistribution of cash, which deserves our main attention. The latter is incidental to individual differences, whereas the essential phenomenon is that which occurs in the simplest case. Moreover, even in the general case, the shift in the rate of interest is usually the most prominent part of the reaction to a change in the news. The movement in bond-prices is, as the newspapers are accustomed to say, “out of all proportion to the activity of dealing”; ― which is as it should be, in view of individuals being much more similar than they are dissimilar in their reaction to news.

  しかしながら、一般的には、環境の変化や予想の変化は個人の貨幣保有量をいくらか調整させる。―なぜなら、実際、変化は様々な人達の考え方に様々に影響す るからである。ある場合には、環境の違いと貨幣を保有する理由の違いによって、またある場合には、新たな状況に対する知識と解釈の違いによって異なってく る。つまり、新たな利子率の均衡は貨幣保有の再分配を伴うのである。それにもかからず、我々が注目すべきは現金の再分配ではなく利子率の変化なのである。 現金の再分配は個人の相違に付随するものであって、主な現象はもっとも単純なケースでも発生する利子率の変化なのである。さらに、一般的な場合において も、利子率の変化は情勢の変化に対する反応のうちでも通常もっとも目立ったものである。債券価格の動きは、新聞がよく言うように、「取引活動とは不釣合 い」に大きなものである。しかし、新たな情勢に対する個々人の反応は多くの場合よく似たものであるとことを考えれば、それはそうならざるをえないのである (=同じ方向に一斉に動くから)。

II

  Whilst the amount of cash which an individual decides to hold to satisfy the transactions-motive and the precautionary-motive is not entirely independent of what he is holding to satisfy the speculative-motive, it is a safe first approximation to regard the amounts of these two sets of cash-holdings as being largely independent of one another. Let us, therefore, for the purposes of our further analysis, break up our problem in this way.

第2節
  個人が取引動機と予備的動機を満たすために保有しようと決める現金の量は、投機的動機を満たすために保有している貨幣の量とまったく無関係ではないが、こ れらの両者の貨幣保有量は互いにほとんど無関係であると言ってよいだろう。したがって、分析を進めるにあたって我々は問題を次のように分割しよう。

  Let the amount of cash held to satisfy the transactions- and precautionary-motives be M1, and the amount held to satisfy the speculative-motive be M2. Corresponding to these two compartments of cash, we then have two liquidity functions L1 and L2. L1 mainly depends on the level of income, whilst L2 mainly depends on the relation between the current rate of interest and the state of expectation. Thus

  つまり、取引動機と予備的動機を満たすための貨幣保有量をM1とし、投機的動機と満たすための貨幣保有量をM2とするのである。そして、この二つの現金の 区分に対応する二つの流動性関数をL1とL2とする。L1は主に所得水準に依存し、L2は現行利子率と予想状況との関係に主に依存する。すると、
 
          M = M1 + M2 = L1(Y) + L2(r) ,

where L1 is the liquidity function corresponding to an income Y, which determines M1, and L2 is the liquidity function of the rate of interest r, which determines M2. It follows that there are three matters to investigate: (i) the relation of changes in M to Y and r, (ii) what determines the shape of L1, (iii) what determines the shape of L2.

        M=M1+M2=L1(Y)+L2(r)となる。

ここで、L1は所得Yに対応する流動性関数でありM1を決定する。L2は利子率rの流動性関数でありM2を決定する。そうすると調べるべきものが三つあって。(一)Mの変化がYとrにどう関係するか。(二)L1の形を決定するものは何か。(三)L2を決定するものは何か。

(i) The relation of changes in M to Y and r depends, in the first instance, on the way in which changes in M come about. Suppose that M consists of gold coins and that changes in M can only result from increased returns(収穫、報酬) to the activities of gold-miners who belong to the economic system under examination. In this case changes in M are, in the first instance, directly associated with changes in Y, since the new gold accrues as someone's income. Exactly the same conditions hold if changes in M are due to the Government printing money wherewith to meet its current expenditure; ― in this case also the new money accrues as someone's income. The new level of income, however, will not continue sufficiently high(程度) for the requirements of M1 to absorb the whole of the increase in M; and some portion of the money will seek an outlet in buying securities or other assets until r has fallen so as to bring about an increase in the magnitude of M2 and at the same time to stimulate a rise in Y to such an extent that the new money is absorbed either in M2 or in the M1 which corresponds to the rise in Y caused by the fall in r. Thus at one remove this case comes to the same thing as the alternative case, where the new money can only be issued in the first instance by a relaxation of the conditions of credit by the banking system, so as to induce someone to sell the banks a debt or a bond in exchange for the new cash.

(一)Mの変化がYとrにどう関係するかは、まず第一に、Mの変化の起こり方に依存する。Mは金貨からなり立ち、Mの変化は検討対象である経済に属する金 鉱の鉱夫たちの活動報酬の増加から来るとしよう。―このケースでは、まず、新たな金は誰かの所得として発生するから、Mの変化はYの変化と直接つながって いる。これとまったく同じ状況が当てはまるのが、政府が支出を埋めるために紙幣を印刷することでMの変化が起こる場合である。―このケースでも新たな貨幣 は誰かの所得として発生する。しかしながら、新たな所得水準の範囲は、M1の容量がMの増加分を全て吸収できるような範囲に留まっていることはない。貨幣 のある部分は証券や他の資産の購入に捌け口を求めるようになり、ついにはrが下落して、その結果、M2の量が増えて、同時にYの上昇が促される。その結果 生まれた新たな貨幣はM2に吸収されるか、rの下落によって起きたYの上昇に対応するM1に吸収される。つまり、このケースはもう一つのケース(=公開市 場操作)、即ち、人々が銀行に債券を新たな現金と交換に売る気になるように、銀行が信用条件を緩める(=債権に高値をつける)ことで初めて新たな貨幣が発 生するケースと殆ど同じことになるのである。

  It will, therefore, be safe for us to take the latter case as typical. A change in M can be assumed to operate by changing r, and a change in r will lead to a new equilibrium partly by changing M2 and partly by changing Y and therefore M1. The division of the increment of cash between M1 and M2 in the new position of equilibrium will depend on the responses of investment to a reduction in the rate of interest and of income to an increase in investment.[1] Since Y partly depends on r, it follows that a given change in M has to cause a sufficient change in r for the resultant changes in M1 and M2 respectively to add up to the given change in M.
 
  したがって、この二番目のケースを典型と見て間違いはないだろう。Mの変化はrを変化させ、rの変化は一方でM2を変化させ一方でYをついでM1を変化さ せて新たな均衡に至るのである。新たな均衡において現金の増加分がM1とM2にどう分割されるかは、利子率の低下に投資がどう反応するか、投資の増加に所 得がどう反応するかによって決まる[1]。Mの変化はrの変化をもたらし、そのrの変化が今度はM1とM2をそれぞれ変化させるが、この二つを合わせると 最初のMの変化になる。なぜならYの一部はrに依存するからである。

(ii) It is not always made clear whether the income-velocity of money is defined as the ratio of Y to M or as the ratio of Y to M1. I propose, however, to take it in the latter sense. Thus if V is the income-velocity of money,

            L1(Y) = Y/V = M1.

(ニ)貨幣の所得速度の定義はYとMの割合(=Y/M)なのかYとM1の割合(=Y/M1)なのかは必ずしも明らかではない。しかしながら、私は後者の定義を採用したい。つまり、∨を貨幣の所得速度とすると、

            L1(Y)= Y/∨ = M1 となる。

There is, of course, no reason for supposing that V is constant. Its value will depend on the character of banking and industrial organisation, on social habits, on the distribution of income between different classes and on the effective cost of holding idle cash. Nevertheless, if we have a short period of time in view and can safely assume no material change in any of these factors, we can treat V as nearly enough constant.

もちろん、∨が固定していると想定する理由はない。その値は銀行と産業組織の性格、社会習慣、所得の階級間の分配、遊休現金を保有する実際の費用に依存す る。にもかかわらず、短期を視野においてこれらの要素に大きな変化がないと想定するなら、我々は∨を定数であると見做してよい。

(iii) Finally there is the question of the relation between M2 and r. We have seen in Chapter 13 that uncertainty as to the future course of the rate of interest is the sole intelligible explanation of the type of liquidity-preference L2 which leads to the holding of cash M2. It follows that a given M2 will not have a definite quantitative relation to a given rate of interest of r; ― what matters is not the absolute level of r but the degree of its divergence from what is considered a fairly safe level of r, having regard to those calculations of probability which are being relied on. Nevertheless, there are two reasons for expecting that, in any given state of expectation, a fall in r will be associated with an increase in M2. In the first place, if the general view as to what is a safe level of r is unchanged, every fall in r reduces the market rate relatively to the “safe” rate and therefore increases the risk of illiquidity; and, in the second place, every fall in r reduces the current earnings from illiquidity, which are available as a sort of insurance premium to offset the risk of loss on capital account, by an amount equal to the difference between the squares of the old rate of interest and the new.

(三)最後にM2とrの関係の問題が残る。第13章で我々は、現金M2の保有を促す流動性選好L2を唯一つ合理的に説明するのは将来の利子率の不確定性が であることを見出した。すると、あるM2がある利子率rと量的に明確な関係にあるのではないということになる。―重要な事は、rがいくらであるかではな く、信頼できる確立計算を尊重した場合、rが充分に安全な水準からどれだけ離れているかなのである。にもかかわらず、期待を一定とすると、rの下落がM2 の増加を伴うと予想する二つの理由がある。まず第一に、rの安全な水準についての一般的な見方を一定とすると、rの下落は市場利子率を相対的に「安全な利 子率」よりも引き下げ、したがって、非流動性(=債券)のリスクを増加するからであり、第二に、rの下落は(資本勘定における損失リスクを相殺する保険プ レミアムとして利用可能な)非流動性からの当座の収益を、古い利子率の二乗と新たな利子率の二乗の差に等しい額だけ引き下げるからである。

For example, if the rate of interest on a long-term debt is 4 per cent., it is preferable to sacrifice liquidity unless on a balance of probabilities it is feared that the long-term rate of interest may rise faster than by 4 per cent. of itself per annum, i.e. by an amount greater than 0.16 per cent. per annum. If, however, the rate of interest is already as low as 2 per cent., the running yield will only offset a rise in it of as little as 0.04 per cent. per annum. This, indeed, is perhaps the chief obstacle to a fall in the rate of interest to a very low level. Unless reasons are believed to exist why future experience will be very different from past experience, a long-term rate of interest of (say) 2 per cent. leaves more to fear than to hope, and offers, at the same time, a running yield which is only sufficient to offset a very small measure of fear.

例えば、もし長期債権の利子率が4%なら、長期利子率が年にそれ自身(=4%)の4%以上つまり年に0.16%以上上昇する恐れが確率的にないときは、流 動性を手放すのが望ましい。しかしながら、もし利子率がすでに2%にまで下がっているなら、当座の収益はわずか年0.04%の上昇分を埋め合わせするだけ である(=流動性を保持するのが望ましい)。確かに、恐らく主にこの事によって利子率があまり低い水準に下がることをくい止められているのである。きっと 未来の体験は過去とは違うはずだと信じる理由がないかぎり、長期の利子率が(例えば)2%である場合には希望より不安の方が多いし、そこから得られる当座 の収益も気休め程度でしかない。

  It is evident, then, that the rate of interest is a highly psychological phenomenon. We shall find, <indeed ,in Book V that it cannot be> in equilibrium at a level below the rate which corresponds to full employment; because at such a level a state of true inflation will be produced, with the result that M1 will absorb ever-increasing quantities of cash. But at a level above the rate which corresponds to full employment, the long-term market-rate of interest will depend, not only on the current policy of the monetary authority, but also on market expectations concerning its future policy. The short-term rate of interest is easily controlled by the monetary authority, both because it is not difficult to produce a conviction(確信度) that its policy will not greatly change in the very near future, and also because the possible loss is small compared with the running yield (unless it is approaching vanishing point). But the long-term rate may be more recalcitrant when once it has fallen to a level which, on the basis of past experience and present expectations of future monetary policy, is considered “unsafe” by representative opinion. For example, in a country linked to an international gold standard(金本位制), a rate of interest lower than prevails elsewhere will be viewed with a justifiable lack of confidence(確信度の欠如); yet a domestic rate of interest dragged up to a parity with the highest rate (highest after allowing for risk) prevailing in any country belonging to the international system may be much higher than is consistent with domestic full employment.

  以上から、利子率とは非常に心理的な現象だということは明らかである。確かに、第5巻で我々は、利子率が完全雇用に対応するレベル以下で均衡することはあ り得ないことを知る。なぜなら、そんな低い利子率では真性インフレーション(=既出)になってしまい、その結果、増え続ける現金量をM1が吸収(→利子率 上昇)することになるからである。しかし、完全雇用に対応する利子率を上回るレベルでは、長期の市場利子率は、貨幣当局の政策によって変化するし、将来の 政策に対する市場の予想によっても変化する。短期の利子率は貨幣当局によって容易にコントロールできる。近い将来に政策が大きく変化することはないという 確信をもたらすことは難しいことではないし、当座の収益(それがゼロに近いものでない限り)と比べて損失の可能性は小さいからである。しかし、長期の利子 率は、過去の経験および将来の金融政策についての現在の予想とに基づく代表的な意見によって「危険」とされるレベルまで一旦下がってしまうと、それを制御 するのはかなり難しい。例えば、国際的な金本位制に結びついている国で、他の地域よりも低い利子率になっていると、それを知った人達は当然確信(=投資意 欲)を失うだろう。しかし、国内の利子率を金本位制に属する国の一番高い利子率に等しくなるまで(危険を織り込み済みで)引き上げたら、国内の完全雇用と 両立する利子率よりもかなり高い利子率になる可能性がある。

  Thus a monetary policy which strikes public opinion as being experimental in character or easily liable to change may fail in its objective of greatly reducing the long-term rate of interest, because M2 may tend to increase almost without limit in response to a reduction of r below a certain figure. The same policy, on the other hand, may prove easily successful if it appeals to public opinion as being reasonable and practicable and in the public interest, rooted in strong conviction, and promoted by an authority unlikely to be superseded.

  つまり、社会にとって試験的な性格のものだと受け取られるような金融政策や、すぐに変化するような金融政策は、長期金利を大きく下げる目的を達成できな い。なぜなら、rがある一定の数字より下がると、それに対応してM2が際限なく増加し続けるからである(=現金が市場に流れない)。一方で、同じ政策で も、合理的で実行可能で社会のためになると大衆に思われ、強い確信に根ざし、余人に代えがたい権威を持って推進されるなら、容易に成功するだろう。

  It might be more accurate, perhaps, to say that the rate of interest is a highly conventional, rather than a highly psychological, phenomenon. For its actual value is largely governed by the prevailing view as to what its value is expected to be. Any level of interest which is accepted with sufficient conviction as likely to be durable will be durable; subject, of course, in a changing society to fluctuations for all kinds of reasons round the expected normal. In particular, when M1 is increasing faster than M, the rate of interest will rise, and vice versa. But it may fluctuate for decades about a level which is chronically too high for full employment; ― particularly if it is the prevailing opinion that the rate of interest is self-adjusting, so that the level established by convention is thought to be rooted in objective grounds much stronger than convention, the failure of Employment to attain an optimum level being in no way associated, in the minds either of the public or of authority, with the prevalence of an inappropriate range of rates of interest.

  おそらく、利子率は高度に心理的な現象というよりは高度の慣習的な現象であると言ったほうが正確かもしれない。というのは、利子率の実際の値はその予想さ れる値についての支配的な意見に大きく左右されるからである。どんな利子率であっても、それが充分な確信を持って安定していると受け取られるものは実際も 安定し続けるのである。もちろん、変化する社会においては予想される標準値の前後で様々な理由から多少変動することはある。特に、M1がMより急速に増加 する(=M2が減る)と利子率は上昇し、逆にMがM1より急速に増える(=M2が増える)と利子率は下落する。しかし、利子率は何十年も完全雇用にとって は高すぎるレベルで変動することがある。― 特に、利子率は自己調整的というのが支配的な意見で、そのために、慣習の定めた水準が慣習よりも強力な客観的 根拠に基づいていると思われており、さらに、雇用が最高水準に達することが出来ないのは利子率が不適当な範囲にある事とは関係がないと、社会や当局に思わ れている場合には、そうである。

  The difficulties in the way of maintaining effective demand at a level high enough to provide full employment, which ensue from the association of a conventional and fairly stable long-term rate of interest with a fickle and highly unstable marginal efficiency of capital, should be, by now, obvious to the reader.

  完全雇用をもたらす充分な有効需要を維持する妨げとなっている様々な困難は、慣習的でかなり安定した長期の利子率と、気まぐれて極めて不安定な資本の限界効率の組み合わせから生まれていることは、もはや読者には明らかだろう。

  Such comfort as we can fairly take from more encouraging reflections must be drawn from the hope that, precisely because the convention is not rooted in secure knowledge, it will not be always unduly resistant to a modest measure of persistence and consistency of purpose by the monetary authority. Public opinion can be fairly rapidly accustomed to a modest fall in the rate of interest and the conventional expectation of the future may be modified accordingly; thus preparing the way for a further movement ― up to a point. The fall in the long-term rate of interest in Great Britain after her departure from the gold standard provides an interesting example of this; ― the major movements were effected by a series of discontinuous jumps, as the liquidity function of the public, having become accustomed to each successive reduction, became ready to respond to some new incentive in the news or in the policy of the authorities.

 もっと楽観的に考えて、慣習は確実な知識に根ざしているものではないから、貨幣当局が適度に粘り強く一貫した目的をもっているなら、慣習もそれほど強く 抵抗しないだろうと考えるのは、多少の気休めになるかもしれない。それに、世論は利子率の適度な下落にかなり急速に慣れるし、将来に対する慣習的な予想も それに応じて変えることが出来る。つまり変化への道筋は準備されているのである―ある程度までだが。金本位制を離脱したあとの英国の長期金利の下落はこの 興味深い実例を与えている。―社会の流動性関数が連続的な下落に慣れていたので、新たな情勢や当局の政策による新しい刺激に反応する準備ができていたの で、英国では大きな変化(=利子率の低下)が連続的なジャンプによって引き起こされたのである。

III

  We can sum up the above in the proposition that in any given state of expectation there is in the minds of the public a certain potentiality towards holding cash beyond what is required by the transactions-motive or the precautionary-motive, which will realise itself in actual cash-holdings in a degree which depends on the terms on which the monetary authority is willing to create cash. It is this potentiality which is summed up in the liquidity function L2.

第3節
 これまでのところを要約すると、一定の予想のもとで、社会は心理的に取引動機と予備的動機によって必要とされる(=M1)以上の現金を保有しようとする 潜在的傾向があって、それが現実の貨幣保有となる程度は、貨幣当局が貨幣創造をしようとする条件(=利子率)に依存する。この潜在的傾向が流動性関数L2 に要約されているのである。
 
  Corresponding to the quantity of money created by the monetary authority, there will, therefore, be cet. par. a determinate(被決定の) rate of interest or, more strictly, a determinate complex of rates of interest for debts of different maturities. The same thing, however, would be true of any other factor in the economic system taken separately. Thus this particular analysis will only be useful and significant in so far as there is some specially direct or purposive connection between changes in the quantity of money and changes in the rate of interest. Our reason for supposing that there is such a special connection arises from the fact that, broadly speaking, the banking system and the monetary authority are dealers in money and debts and not in assets or consumables.

  したがって、他の条件が同じなら、貨幣当局が創造した貨幣量に対応して、利子率、もっと厳密には、様々な満期をもつ債権の利子率複合体が決定されることに なる。しかしながら、経済の他のどの要素でも個別に取り上げると、同じことが当てはまる(=貨幣量以外によって利子率が決まることもある)。つまり、貨幣 量の変化と利子率の変化の間に特に直接的なつながり、目的にかなったつながりがある場合にだけ、この特別な分析(=貨幣量と利子率の対応)が有用であり有 意義となる。そのような特別なつながりがあると考える一つの理由は、概して銀行と貨幣当局は貨幣と債権を扱うだけで、資産や消費財を扱わないからである。
 
  If the monetary authority were prepared to deal both ways on specified terms in debts of all maturities, and even more so if it were prepared to deal in debts of varying degrees of risk, the relationship between the complex of rates of interest and the quantity of money would be direct. The complex of rates of interest would simply be an expression of the terms on which the banking system is prepared to acquire or part with debts; and the quantity of money would be the amount which can find a home in the possession of individuals who ― after taking account of all relevant circumstances ― prefer the control of liquid cash to parting with it in exchange for a debt on the terms indicated by the market rate of interest. Perhaps a complex offer by the central bank to buy and sell at stated prices gilt-edged bonds of all maturities, in place of the single bank rate for short-term bills, is the most important practical improvement which can be made in the technique of monetary management.

 もし貨幣当局が指定した条件であらゆる満期の債権を売り買い両方向で取り扱う準備ができているなら、そして、さらに様々なリスクの債権を扱う準備ができ ているなら、利子率複合体と貨幣量の関係は直接的になる。そうすると、利子率複合体は単に銀行が債権を買い入れるか手放すかの用意がある条件の表現でしか ないだろう。そして貨幣量とは、― 関係するあらゆる状況を考えた後に― 市場利子率として表れた条件で債権と交換に流動的現金を手放すよりは流動的現金を持ち続ける方を選ぶ人の所有に帰す る量となる。おそらく中央銀行が、短期の証券に対する単一の銀行利子率の代わりに、あらゆる満期の優良債券を指定した価格で売買することを組み合わせて提 示するようになった事は、貨幣管理の技術の最も重要な実践的進歩である。
 
  To-day, however, in actual practice, the extent to which the price of debts as fixed by the banking system is “effective” in the market, in the sense that it governs the actual market-price, varies in different systems(経済システム). Sometimes the price is more effective in one direction than in the other; that is to say, the banking system may undertake to purchase debts at a certain price but not necessarily to sell them at a figure near enough to its buying-price to represent no more than a dealer's turn, though there is no reason why the price should not be made effective both ways with the aid of open-market operations. There is also the more important qualification which arises out of the monetary authority not being, as a rule, an equally willing dealer in debts of all maturities. The monetary authority often tends in practice to concentrate upon short-term debts and to leave the price of long-term debts to be influenced by belated and imperfect reactions from the price of short-term debts; ― though here again there is no reason why they need do so.
 
  しかしながら、今日の実際の慣例では、銀行が決めた債権価格が、どれほど現実の市場価格に決定力をもつかという意味で、市場で「有効」となる程度は、それ ぞれの経済によって異なっている。時々その価格は売買の一つの向きより反対向きのほうが「有効」であることがある。つまり、銀行は債権をある価格で購入し ようとしても、必ずしも、その購入価格と近い価格、ディーラーの値ざやしか表さないような価格で売るとは限らない。とはいえ、その価格が公開市場操作の力 で売買の両方向に「有効」とならない理由はない。また、貨幣当局が一般的に全期間の債権を同じように扱おうとはしないということから来る更に重要な限定条 件がある。つまり、貨幣当局はしばしば実際には短期の債権に集中して、長期の債権価格は後になって短期の債権価格から不完全な影響を受けるに任せる傾向が あるのだ。―とはいえ、ここでもまた必ず彼らがそうする理由はない。

Where these qualifications operate, the directness of the relation between the rate of interest and the quantity of money is correspondingly modified. In Great Britain the field of deliberate control appears to be widening. But in applying this theory in any particular case allowance must be made for the special characteristics of the method actually employed by the monetary authority. If the monetary authority deals only in short-term debts, we have to consider what influence the price, actual and prospective, of short-term debts exercises on debts of longer maturity.

このような限定条件が働く場合には、利子率と貨幣量との関係の直接性はそれに応じて緩和される。英国では意図的なコントロールの範囲は広がっているように 見える。しかし、この理論を個別のケースに適用するさいには、貨幣当局が実際に採用する方法の特殊な性格を考慮に入れる必要がある。もし貨幣当局が短期債 権だけを扱うなら、短期債権の現在と将来の価格が長期の債権にどういう影響を与えるかを考えなければならない。

  Thus there are certain limitations on the ability of the monetary authority to establish any given complex of rates of interest for debts of different terms and risks, which can be summed up as follows:

  つまり、貨幣当局が様々な条件やリスクの債権の複合利子率を確立する能力にはある種の限界がある。それを以下に要約しよう。

(1) There are those limitations which arise out of the monetary authority's own practices in limiting its willingness to deal to debts of a particular type.

(1)貨幣当局が特定のタイプの債権を扱いたがる自分の習慣からくる限界

(2) There is the possibility, for the reasons discussed above, that, after the rate of interest has fallen to a certain level, liquidity-preference may become virtually absolute in the sense that almost everyone prefers cash to holding a debt which yields so low a rate of interest. In this event the monetary authority would have lost effective control over the rate of interest. But whilst this limiting case might become practically important in future, I know of no example of it hitherto. Indeed, owing to the unwillingness of most monetary authorities to deal boldly in debts of long term, there has not been much opportunity for a test. Moreover, if such a situation were to arise, it would mean that the public authority itself could borrow through the banking system on an unlimited scale at a nominal rate of interest.

(2)上で述べた理由から、利子率がある水準に低下したあとは、殆どすべての人がそれほど低い利子しかもたらさない債権を持つよりは現金を持つ方を選ぶと いう意味で、流動性選好がほとんど絶対的になる可能性がある。こうなったら、貨幣当局は利子率に対して効果的なコントロールを失ってしまう(=流動性の 罠)。しかし、このような限定的なケースは将来において実際上は重要になるが、これまでのところそんな例を知らない。確かに、多くの貨幣当局が長期の債権 を大胆に扱うことを嫌がるために、コントロールを失うほどの利子率の低下を試す機会は多くなかった。さらに、もしそんな状況が発生したら、それは公共団体 が名ばかりの利子率でいくらでも銀行を通じて借入れすることが出来ることを意味している。

(3) The most striking examples of a complete breakdown of stability in the rate of interest, due to the liquidity function flattening out in one direction or the other, have occurred in very abnormal circumstances. In Russia and Central Europe after the war a currency crisis or flight from the currency was experienced, when no one could be induced to retain holdings either of money or of debts on any terms whatever, and even a high and rising rate of interest was unable to keep pace with the marginal efficiency of capital (especially of stocks of liquid goods) under the influence of the expectation of an ever greater fall in the value of money; whilst in the United States at certain dates in 1932 there was a crisis of the opposite kind ― a financial crisis or crisis of liquidation, when scarcely anyone could be induced to part with holdings of money on any reasonable terms.

(3)流動性関数がどちらかの方向に完全に平たくなったことに起因して、利子率の安定性が完全に崩壊した最も衝撃的な例は、非常に異常な状況の中で発生し た。第一次大戦後のロシアや中央ヨーロッパでは通貨危機、つまり通貨からの逃避が経験された。当時は誰もが貨幣の保有もどんな条件での債権の保有もする気 持ちがなくなった(=金や現物を持ちたがる)。また、貨幣価値がさらに大きく下落すると予想されたおかげで、どんなに利子率が上昇しても、資本の限界効率 (物価上昇で特に流動的な財の在庫の価値が上昇)の上昇する歩調(=既出)について行く事ができなかった。一方、合衆国では1932年のある日、逆方向の 危機が発生した。金融恐慌あるいは清算恐慌である。その時はほとんど誰もどんな条件でも貨幣の保有をやめる気にはなれなかった。

(4) There is, finally, the difficulty discussed in section iv of Chapter 11, p. 144, in the way of bringing the effective rate of interest below a certain figure, which may prove important in an era of low interest-rates; namely the intermediate costs(仲介手数料) of bringing the borrower and the ultimate lender together, and the allowance for risk, especially for moral risk, which the lender requires over and above(~に加えて) the pure rate of interest(=既出). As the pure rate of interest declines it does not follow that the allowances for expense(=上の仲介手数料) and risk decline pari passu. Thus the rate of interest which the typical borrower has to pay may decline more slowly than the pure rate of interest, and may be incapable of being brought, by the methods of the existing banking and financial organisation, below a certain minimum figure. This is particularly important if the estimation(推定) of moral risk is appreciable. For where the risk is due to doubt in the mind of the lender concerning the honesty of the borrower, there is nothing in the mind of a borrower who does not intend to be dishonest to offset the resultant higher charge. It is also important in the case of short-term loans (e.g. bank loans) where the expenses are heavy; ― a bank may have to charge its customers 1 1/2 to 2 per cent., even if the pure rate of interest to the lender is nil.

(4)144頁の第11章第4節「リスクについて」で論じたある種の障害があって、それが「有効」利子率を一定以下にすることをさまたげている。低利子率 の時代には深刻な問題で、それは借り手と究極的貸し手とを引き合わせるための仲介手数料と、貸し手が純粋利子率に加えて要求するリスクの引当金、特にモラ ルリスクの引当金である。純粋利子率が下落しても、それに歩調を合わせて手数料とリスクの引当金が下がるわけではない。つまり、典型的な借り手が支払わね ばならない利子率は、純粋利子率よりも下落が遅いので、現行の銀行組織と金融組織の方法によってはある最少の数字以下に下げることが出来ない。このこと は、もしモラルリスクの推定がかなり大きいものなら特に深刻である。というのは、リスクが借手の誠実さに対する貸手の疑念から来るものなら、不誠実なつも りのない借手の心にはそんな追加料金を支払う理由は何もないからである。また、手数料が高くつく短期ローン(例えば銀行のローン)の場合も深刻である。―  たとえ貸手にとっては純粋利子率はゼロであっても、銀行は顧客に対して1.5%から2%の利子を課さねばならないからである。

IV

  At the cost of anticipating what is more properly the subject of Chapter 21 below it may be interesting briefly at this stage to indicate the relationship of the above to the Quantity Theory of Money.

第4節

  第21章のテーマとするほうが相応しいことを先取りすることになるが、この段階で簡単にこの章の問題と貨幣数量節との関係を指摘しておくことは興味深い。

  In a static society or in a society in which for any other reason no one feels any uncertainty about the future rates of interest, the Liquidity Function L2 or the propensity to hoard (as we might term it), will always be zero in equilibrium. Hence in equilibrium M2 = 0 and M = M1; so that any change in M will cause the rate of interest to fluctuate until income reaches a level at which the change in M1 is equal to the supposed change in M. Now M1V = Y, where V is the income-velocity of money as defined above and Y is the aggregate income. Thus if it is practicable to measure the quantity, 0, and the price, P, of current output, we have Y = OP, and, therefore, MV = OP; which is much the same as the Quantity Theory of Money in its traditional form.[2]

  静的な社会、あるいは誰も将来の利子率について不確定性を感じないような社会では、流動性関数L2あるいは(こういっていいのなら)保蔵性向は均衡におい て常にゼロになる。したがって、均衡においてはM2=0であってM=M1ということになる。つまり、Mの変化は利子率を変化させて、それはM1の変化がM の変化と等しくなるような(=M2がゼロになるような)所得レベルに達するまで続くということである。その時、M1×∨=Yが成り立つ。ここで、∨は上記 で定義した貨幣の所得速度でありYは総所得である。つまり、もし産出物の量Oと価格Pが計測できるなら、Y=O×Pであり、したがって、M×∨=O×P (←M1=M)である。これは貨幣数量説の伝統的な式とほぼ同じである[2]。

  For the purposes of the real world it is a great fault in the Quantity Theory that it does not distinguish between changes in prices which are a function of changes in output, and those which are a function of changes in the wage-unit.[3] The explanation of this omission is, perhaps, to be found in the assumptions that there is no propensity to hoard and that there is always full employment. For in this case, O being constant and M2 being zero, it follows, if we can take V also as constant, that both the wage-unit and the price-level will be directly proportional to the quantity of money.

  現実の世界にとっては貨幣数量説は大きな欠陥がある。それは産出量の変化の関数である物価の変化と、単位賃金の変化の関数である物価の変化を区別していな ことである[3]。この欠陥はおそらく保蔵性向がなく常に完全雇用状態であるという想定のせいだろう。というのは、この場合、Oは定数でありM2はゼロで あり、それはすなわち、もし∨も定数に出来るなら、単位賃金と物価水準は貨幣量に直接比例することになるからである。

Author's Footnotes

[1]. We must postpone to Book V. the question of what will determine the character of the new equilibrium.

[2]. If we had defined V, not as equal to Y/M1, but as equal to Y/M, then, of course, the Quantity Theory is a truism which holds in all circumstances, though without significance.

[3]. This point will be further developed in Chapter 21 below.

著者注

[1] 新たな均衡の性格を決めるものは何かという問題は第5巻に先送りする。

[2] もし∨をY/M1ではなくY/Mに等しいとするなら、もちろん貨幣数量説はもはや自明の理であり、どんな状況でも当てはまるが何の意味もなくなってしまう。

[3] この点は21章でさらに扱う。

※第16章以下は訳しているところもある。

Chapter 16. Sundry Observations on the Nature of Capital
I

AN act of individual saving means ― so to speak ― a decision not to have dinner to-day. But it does not necessitate a decision to have dinner or to buy a pair of boots a week hence or a year hence or to consume any specified thing at any specified date. Thus it depresses the business(本文、務め) of preparing to-day's dinner without stimulating the business of making ready for some future act of consumption. It is not a substitution of future consumption-demand for present consumption-demand, ― it is a net diminution of such demand. Moreover, the expectation of future consumption is so largely based on current experience of present consumption that a reduction in the latter is likely to depress the former, with the result that the act of saving will not merely depress the price of consumption-goods and leave the marginal efficiency of existing capital unaffected, but may actually tend to depress the latter also. In this event it may reduce present investment-demand as well as present consumption-demand.

  If saving consisted not merely in abstaining from present consumption but in placing simultaneously a specific order for future consumption, the effect might indeed be different. For in that case the expectation of some future yield from investment would be improved, and the resources released from preparing for present consumption could be turned over to preparing for the future consumption. Not that they necessarily would be, even in this case, on a scale equal to the amount of resources released; since the desired interval of delay might require a method of production so inconveniently “roundabout” as to have an efficiency well below the current rate of interest, with the result that the favourable effect on employment of the forward order for consumption would eventuate not at once but at some subsequent date, so that the immediate effect of the saving would still be adverse to employment. In any case, however, an individual decision to save does not, in actual fact, involve the placing of any specific forward order for consumption, but merely the cancellation of a present order. Thus, since the expectation of consumption is the only raison d'e^tre of employment, there should be nothing paradoxical in the conclusion that a diminished propensity to consume has cet. par. a depressing effect on employment.

The trouble arises, therefore, because the act of saving implies, not a substitution for present consumption of some specific additional consumption which requires for its preparation just as much immediate economic activity as would have been required by present consumption equal in value to the sum saved, but a desire for “wealth” as such, that is for a potentiality of consuming an unspecified article at an unspecified time. The absurd, though almost universal, idea that an act of individual saving is just as good for effective demand as an act of individual consumption, has been fostered by the fallacy, much more specious than the conclusion derived from it, that an increased desire to hold wealth, being much the same thing as an increased desire to hold investments, must, by increasing the demand for investments, provide a stimulus to their production; so that current investment is promoted by individual saving to the same extent as present consumption is diminished.

  It is of this fallacy that it is most difficult to disabuse men's minds. It comes from believing that the owner of wealth desires a capital-asset as such, whereas what he really desires is its prospective yield. Now, prospective yield wholly depends on the expectation of future effective demand in relation to future conditions of supply. If, therefore, an act of saving does nothing to improve prospective yield, it does nothing to stimulate investment. Moreover, in order that an individual saver may attain his desired goal of the ownership of wealth, it is not necessary that a new capital-asset should be produced wherewith to satisfy him. The mere act of saving by one individual, being two-sided as we have shown above, forces some other individual to transfer to him some article of wealth old or new. Every act of saving involves a “forced” inevitable transfer of wealth to him who saves, though he in his turn may suffer from the saving of others. These transfers of wealth do not require the creation of new wealth ― indeed, as we have seen, they may be actively inimical to it. The creation of new wealth wholly depends on the prospective yield of the new wealth reaching the standard set by the current rate of interest. The prospective yield of the marginal new investment is not increased by the fact that someone wishes to increase his wealth, since the prospective yield of the marginal new investment depends on the expectation of a demand for a specific article at a specific date.

Nor do we avoid this conclusion by arguing that what the owner of wealth desires is not a given prospective yield but the best available prospective yield, so that an increased desire to own wealth reduces the prospective yield with which the producers of new investment have to be content. For this overlooks the fact that there is always an alternative to the ownership of real capital-assets, namely the ownership of money and debts; so that the prospective yield with which the producers of new investment have to be content cannot fall below the standard set by the current rate of interest. And the current rate of interest depends, as we have seen, not on the strength of the desire to hold wealth, but on the strengths of the desires to hold it in liquid and in illiquid forms respectively, coupled with the amount of the supply of wealth in the one form relatively to the supply of it in the other. If the reader still finds himself perplexed, let him ask himself why, the quantity of money being unchanged, a fresh act of saving should diminish the sum which it is desired to keep in liquid form at the existing rate of interest.

Certain deeper perplexities, which may arise when we try to probe still further into the whys and wherefores, will be considered in the next chapter.
II

  It is much preferable to speak of capital as having a yield over the course of its life in excess of its original cost, than as being productive. For the only reason why an asset offers a prospect of yielding during its life services having an aggregate value greater than its initial supply price is because it is scarce; and it is kept scarce because of the competition of the rate of interest on money. If capital becomes less scarce, the excess yield will diminish, without its having become less productive ― at least in the physical sense.

  I sympathise, therefore, with the pre-classical doctrine that everything is produced by labour, aided by what used to be called art and is now called technique, by natural resources which are free or cost a rent according to their scarcity or abundance, and by the results of past labour, embodied in assets, which also command a price according to their scarcity or abundance. It is preferable to regard labour, including, of course, the personal services of the entrepreneur and his assistants, as the sole factor of production, operating in a given environment of technique, natural resources, capital equipment and effective demand. This partly explains why we have been able to take the unit of labour as the sole physical unit which we require in our economic system, apart from units of money and of time.

  It is true that some lengthy or roundabout processes are physically efficient. But so are some short processes. Lengthy processes are not physically efficient because they are long. Some, probably most, lengthy processes would be physically very inefficient, for there are such things as spoiling or wasting with time.[1] With a given labour force there is a definite limit to the quantity of labour embodied in roundabout processes which can be used to advantage. Apart from other considerations, there must be a due proportion between the amount of labour employed in making machines and the amount which will be employed in using them. The ultimate quantity of value will not increase indefinitely, relatively to the quantity of labour employed, as the processes adopted become more and more roundabout, even if their physical efficiency is still increasing. Only if the desire to postpone consumption were strong enough to produce a situation in which full employment required a volume of investment so great as to involve a negative marginal efficiency of capital, would a process become advantageous merely because it was lengthy; in which event we should employ physically inefficient processes, provided they were sufficiently lengthy for the gain from postponement to outweigh their inefficiency. We should in fact have a situation in which short processes would have to be kept sufficiently scarce for their physical efficiency to outweigh the disadvantage of the early delivery of their product. A correct theory, therefore, must be reversible so as to be able to cover the cases of the marginal efficiency of capital corresponding either to a positive or to a negative rate of interest; and it is, I think, only the scarcity theory outlined above which is capable of this.

Moreover there are all sorts of reasons why various kinds of services and facilities are scarce and therefore expensive relatively to the quantity of labour involved. For example, smelly processes command a higher reward, because people will not undertake them otherwise. So do risky processes. But we do not devise a productivity theory of smelly or risky processes as such. In short, not all labour is accomplished in equally agreeable attendant circumstances; and conditions of equilibrium require that articles produced in less agreeable attendant circumstances (characterised by smelliness, risk or the lapse of time) must be kept sufficiently scarce to command a higher price. But if the lapse of time becomes an agreeable attendant circumstance, which is a quite possible case and already holds for many individuals, then, as I have said above, it is the short processes which must be kept sufficiently scarce.

Given the optimum amount of roundaboutness, we shall, of course, select the most efficient roundabout processes which we can find up to the required aggregate. But the optimum amount itself should be such as to provide at the appropriate dates for that part of consumers' demand which it is desired to defer. In optimum conditions, that is to say, production should be so organised as to produce in the most efficient manner compatible with delivery at the dates at which consumers' demand is expected to become effective. It is no use to produce for delivery at a different date from this, even though the physical output could be increased by changing the date of delivery; ― except in so far as the prospect of a larger meal, so to speak, induces the consumer to anticipate or postpone the hour of dinner. If, after hearing full particulars of the meals he can get by fixing dinner at different hours, the consumer is expected to decide in favour of 8 o'clock, it is the business of the cook to provide the best dinner he can for service at that hour, irrespective of whether 7.30, 8 o'clock or 8.30 is the hour which would suit him best if time counted for nothing, one way or the other, and his only task was to produce the absolutely best dinner. In some phases of society it may be that we could get physically better dinners by dining later than we do; but it is equally conceivable in other phases that we could get better dinners by dining earlier. Our theory must, as I have said above, be applicable to both contingencies.

  If the rate of interest were zero, there would be an optimum interval for any given article between the average date of input and the date of consumption, for which labour cost would be a minimum; ― a shorter process of production would be less efficient technically, whilst a longer process would also be less efficient by reason of storage costs and deterioration. If, however, the rate of interest exceeds zero, a new element of cost is introduced which increases with the length of the process, so that the optimum interval will be shortened, and the current input to provide for the eventual delivery of the article will have to be curtailed until the prospective price has increased sufficiently to cover the increased cost ― a cost which will be increased both by the interest charges and also by the diminished efficiency of the shorter method of production. Whilst if the rate of interest falls below zero (assuming this to be technically possible), the opposite is the case. Given the prospective consumers' demand, current input to-day has to compete, so to speak, with the alternative of starting input at a later date; and, consequently, current input will only be worth while when the greater cheapness, by reason of greater technical efficiency or prospective price changes, of producing later on rather than now, is insufficient to offset the smaller return from negative interest. In the case of the great majority of articles it would involve great technical inefficiency to start up their input more than a very modest length of time ahead of their prospective consumption. Thus even if the rate of interest is zero, there is a strict limit to the proportion of prospective consumers' demand which it is profitable to begin providing for in advance; and, as the rate of interest rises, the proportion of the prospective consumers' demand for which it pays to produce to-day shrinks pari passu.
III

We have seen that capital has to be kept scarce enough in the long-period to have a marginal efficiency which is at least equal to the rate of interest for a period equal to the life of the capital, as determined by psychological and institutional conditions. What would this involve for a society which finds itself so well equipped with capital that its marginal efficiency is zero and would be negative with any additional investment; yet possessing a monetary system, such that money will “keep” and involves negligible costs of storage and safe custody, with the result that in practice interest cannot be negative; and, in conditions of full employment, disposed to save?

  If, in such circumstances, we start from a position of full employment, entrepreneurs will necessarily make losses if they continue to offer employment on a scale which will utilise the whole of the existing stock of capital. Hence the stock of capital and the level of employment will have to shrink until the community becomes so impoverished that the aggregate of saving has become zero, the positive saving of some individuals or groups being offset by the negative saving of others. Thus for a society such as we have supposed, the position of equilibrium, under conditions of laissez-faire, will be one in which employment is low enough and the standard of life sufficiently miserable to bring savings to zero. More probably there will be a cyclical movement round this equilibrium position. For if there is still room for uncertainty about the future, the marginal efficiency of capital will occasionally rise above zero leading to a “boom”, and in the succeeding “slump” the stock of capital may fall for a time below the level which will yield a marginal efficiency of zero in the long run. Assuming correct foresight, the equilibrium stock of capital which will have a marginal efficiency of precisely zero will, of course, be a smaller stock than would correspond to full employment of the available labour; for it will be the equipment which corresponds to that proportion of unemployment which ensures zero saving.

The only alternative position of equilibrium would be given by a situation in which a stock of capital sufficiently great to have a marginal efficiency of zero also represents an amount of wealth sufficiently great to satiate to the full the aggregate desire on the part of the public to make provision for the future, even with full employment, in circumstances where no bonus is obtainable in the form of interest. It would, however, be an unlikely coincidence that the propensity to save in conditions of full employment should become satisfied just at the point where the stock of capital reaches the level where its marginal efficiency is zero. If, therefore, this more favourable possibility comes to the rescue, it will probably take effect, not just at the point where the rate of interest is vanishing, but at some previous point during the gradual decline of the rate of interest.

We have assumed so far an institutional factor which prevents the rate of interest from being negative, in the shape of money which has negligible carrying-costs(持越費用、在庫維持費). In fact, however, institutional and psychological factors are present which set a limit much above zero to the practicable decline in the rate of interest. In particular the costs of bringing borrowers and lenders together and uncertainty as to the future of the rate of interest, which we have examined above, set a lower limit, which in present circumstances may perhaps be as high as 2 or 2 1/2 per cent. on long term. If this should prove correct, the awkward possibilities of an increasing stock of wealth, in conditions where the rate of interest can fall no further under laissez-faire, may soon be realised in actual experience. Moreover if the minimum level to which it is practicable to bring the rate of interest is appreciably above zero, there is less likelihood of the aggregate desire to accumulate wealth being satiated before the rate of interest has reached its minimum level.

The post-war experiences of Great Britain and the United States are, indeed, actual examples of how an accumulation of wealth, so large that its marginal efficiency has fallen more rapidly than the rate of interest can fall in the face of the prevailing institutional and psychological factors, can interfere, in conditions mainly of laissez-faire, with a reasonable level of employment and with the standard of life which the technical conditions of production are capable of furnishing.

  It follows that of two equal communities, having the same technique but different stocks of capital, the community with the smaller stock of capital may be able for the time being to enjoy a higher standard of life than the community with the larger stock; though when the poorer community has caught up the rich ― as, presumably, it eventually will ― then both alike will suffer the fate of Midas. This disturbing conclusion depends, of course, on the assumption that the propensity to consume and the rate of investment are not deliberately controlled in the social interest but are mainly left to the influences of laissez-faire.

  If ― for whatever reason ― the rate of interest cannot fall as fast as the marginal efficiency of capital would fall with a rate of accumulation corresponding to what the community would choose to save at a rate of interest equal to the marginal efficiency of capital in conditions of full employment, then even a diversion of the desire to hold wealth towards assets, which will in fact yield no economic fruits whatever, will increase economic well-being. In so far as millionaires find their satisfaction in building mighty mansions to contain their bodies when alive and pyramids to shelter them after death, or, repenting of their sins, erect cathedrals and endow monasteries or foreign missions, the day when abundance of capital will interfere with abundance of output may be postponed. “To dig holes in the ground,” paid for out of savings, will increase, not only employment, but the real national dividend of useful goods and services. It is not reasonable, however, that a sensible community should be content to remain dependent on such fortuitous and often wasteful mitigations when once we understand the influences upon which effective demand depends.
IV

Let us assume that steps are taken to ensure that the rate of interest is consistent with the rate of investment which corresponds to full employment. Let us assume, further, that State action enters in as a balancing factor to provide that the growth of capital equipment shall be such as to approach saturation-point at a rate which does not put a disproportionate burden on the standard of life of the present generation.

On such assumptions I should guess that a properly run community equipped with modern technical resources, of which the population is not increasing rapidly, ought to be able to bring down the marginal efficiency of capital in equilibrium approximately to zero within a single generation; so that we should attain the conditions of a quasi-stationary community where change and progress would result only from changes in technique, taste, population and institutions, with the products of capital selling at a price proportioned to the labour, etc., embodied in them on just the same principles as govern the prices of consumption-goods into which capital-charges enter in an insignificant degree.

  If I am right in supposing it to be comparatively easy to make capital-goods so abundant that the marginal efficiency of capital is zero, this may be the most sensible way of gradually getting rid of many of the objectionable features of capitalism. For a little reflection will show what enormous social changes would result from a gradual disappearance of a rate of return on accumulated wealth. A man would still be free to accumulate his earned income with a view to spending it at a later date. But his accumulation would not grow. He would simply be in the position of Pope's father, who, when he retired from business, carried a chest of guineas with him to his villa at Twickenham and met his household expenses from it as required.

Though the rentier would disappear, there would still be room, nevertheless, for enterprise and skill in the estimation of prospective yields about which opinions could differ. For the above relates primarily to the pure rate of interest apart from any allowance for risk and the like, and not to the gross yield of assets including the return in respect of risk. Thus unless the pure rate of interest were to be held at a negative figure, there would still be a positive yield to skilled investment in individual assets having a doubtful prospective yield(純粋利子率が負に維持されることがないかぎり、不確かな予想収益を持つ個々の資産に対する熟練した投資には、依然として正の収益が存在するで あろう). Provided there was some measurable unwillingness to undertake risk, there would also be a positive net yield from the aggregate of such assets over a period of time. But it is not unlikely that, in such circumstances, the eagerness to obtain a yield from doubtful investments might be such that they would show in the aggregate a negative net yield.

利子生活者は消えるとしても、それにもかかわらず、人によって意見の異なる予想収益の評価という技術と冒険心の余地はのこるだろう。というのは、上記の事 実はリスクの要素を排除した純粋利子率に関することで、リスクによる報酬を含めた資産の粗利益に関するものではない。つまり、純粋利子率がマイナスに維持 されることがない限り、不確かな予想収益を持つ個別の資産に対する熟練した投資にはプラスの収益が得られるだろう。さらに、リスクを引き受けることへの明 白な抵抗感があるかぎり、そのような資産を一定期間の後に集計するとプラスの最終収益が生まれていることもある。しかしながら、そのような状況で不確かな 投資から収益をあげようと熱を上げるということは、そのような投資が全体としてマイナスの最終収益を示している可能性があるのが普通である。

Author's Footnotes

[1]. Cf. Marshall's note on Bo"hm-Bawerk, Principles, p. 593.

 

Chapter 17. The Essential Properties of Interest and Money
I

  IT seems, then, that the rate of interest on money plays a peculiar part in setting a limit to the level of employment, since it sets a standard to which the marginal efficiency of a capital-asset must attain if it is to be newly produced. That this should be so, is, at first sight, most perplexing. It is natural to enquire wherein the peculiarity of money lies as distinct from other assets, whether it is only money which has a rate of interest, and what would happen in a non-monetary economy. Until we have answered these questions, the full significance of our theory will not be clear.

The money-rate of interest ― we may remind the reader ― is nothing more than the percentage excess of a sum of money contracted for forward delivery, e.g. a year hence, over what we may call the “spot” or cash price of the sum thus contracted for forward delivery. It would seem, therefore, that for every kind of capital-asset there must be an analogue of the rate of interest on money. For there is a definite quantity of (e.g.) wheat to be delivered a year hence which has the same exchange value to-day as 1000 quarters of wheat for “spot” delivery. If the former quantity is 105 quarters, we may say that the wheat-rate of interest is 5 per cent. per annum; and if it is 95 quarters, that it is minus 5 per cent. per annum. Thus for every durable commodity we have a rate of interest in terms of itself, ― a wheat-rate of interest, a copper-rate of interest, a house-rate of interest, even a steel-plant-rate of interest.

The difference between the “future” and “spot” contracts for a commodity, such as wheat, which are quoted in the market, bears a definite relation to the wheat-rate of interest, but, since the future contract is quoted in terms of money for forward delivery and not in terms of wheat for spot delivery, it also brings in the money-rate of interest. The exact relationship is as follows:

Let us suppose that the spot price of wheat is £100 per 100 quarters, that the price of the “future” contract for wheat for delivery a year hence is £107 per 100 quarters, and that the money-rate of interest is 5 per cent; what is the wheat-rate of interest? £100 spot will buy £105 for forward delivery, and £105 for forward delivery will buy (105/107).100 (=98) quarters for forward-delivery. Alternatively £100 spot will buy 100 quarters of wheat for spot delivery. Thus 100 quarters of wheat for spot delivery will buy 98 quarters for forward delivery. It follows that the wheat-rate of interest is minus 2 per cent. per annum.[1]

  It follows from this that there is no reason why their rates of interest should be the same for different commodities, ― why the wheat-rate of interest should be equal to the copper-rate of interest. For the relation between the “spot” and “future” contracts, as quoted in the market, is notoriously different for different commodities. This, we shall find, will lead us to the clue we are seeking. For it may be that it is the greatest of the own-rates of interest (as we may call them) which rules the roost (because it is the greatest of these rates that the marginal efficiency of a capital-asset must attain if it is to be newly produced); and that there are reasons why it is the money-rate of interest which is often the greatest (because, as we shall find, certain forces, which operate to reduce the own-rates of interest of other assets, do not operate in the case of money).

  It may be added that, just as there are differing commodity-rates of interest at any time, so also exchange dealers are familiar with the fact that the rate of interest is not even the same in terms of two different moneys, e.g. sterling and dollars. For here also the difference between the “spot” and “future” contracts for a foreign money in terms of sterling are not, as a rule, the same for different foreign moneys.

Now each of these commodity standards offers us the same facility as money for measuring the marginal efficiency of capital. For we can take any commodity we choose, eg. wheat; calculate the wheat-value of the prospective yields of any capital asset; and the rate of discount which makes the present value of this series of wheat annuities equal to the present supply price of the asset in terms of wheat gives us the marginal efficiency of the asset in terms of wheat. If no change is expected in the relative value of two alternative standards, then the marginal efficiency of a capital-asset will be the same in whichever of the two standards it is measured, since the numerator and denominator of the fraction which leads up to the marginal efficiency will be changed in the same proportion. If, however, one of the alternative standards is expected to change in value in terms of the other, the marginal efficiencies of capital-assets will be changed by the same percentage, according to which standard they are measured in. To illustrate this let us take the simplest case where wheat, one of the alternative standards, is expected to appreciate at a steady rate of a per cent. per annum in terms of money; the marginal efficiency of an asset, which is x per cent. in terms of money, will then be x - a per cent. in terms of wheat. Since the marginal efficiencies of all capital-assets will be altered by the same amount, it follows that their order of magnitude will be the same irrespective of the standard which is selected.

  If there were some composite commodity which could be regarded strictly speaking as representative, we could regard the rate of interest and the marginal efficiency of capital in terms of this commodity as being, in a sense, uniquely the rate of interest and the marginal efficiency of capital. But there are, of course, the same obstacles in the way of this as there are to setting up a unique standard of value.

So far, therefore, the money-rate of interest has no uniqueness compared with other rates of interest, but is on precisely the same footing. Wherein, then, lies the peculiarity of the money-rate of interest which gives it the predominating practical importance attributed to it in the preceding chapters? Why should the volume of output and employment be more intimately bound up with the money-rate of interest than with the wheat-rate of interest or the house-rate of interest?
II

Let us consider what the various commodity-rates of interest over a period of (say) a year are likely to be for different types of assets. Since we are taking each commodity in turn as the standard, the returns on each commodity must be reckoned in this context as being measured in terms of itself.

There are three attributes which different types of assets possess in different degrees; namely, as follows:

(i) Some assets produce a yield or output q, measured in terms of themselves, by assisting some process of production or supplying services to a consumer.

(ii) Most assets, except money, suffer some wastage or involve some cost through the mere passage of time (apart from any change in their relative value), irrespective of their being used to produce a yield; i.e. they involve a carrying-cost c measured in terms of themselves. It does not matter for our present purpose exactly where we draw the line between the costs which we deduct before calculating q and those which we include in c, since in what follows we shall be exclusively concerned with q - c.

(iii) Finally, the power of disposal over an asset during a period may offer a potential convenience or security, which is not equal for assets of different kinds, though the assets themselves are of equal initial value. There is, so to speak, nothing to show for this at the end of the period in the shape of output; yet it is something for which people are ready to pay something. The amount (measured in terms of itself) which they are willing to pay for the potential convenience or security given by this power of disposal (exclusive of yield or carrying-cost attaching to the asset), we shall call its liquidity-premium(流動性打分、流動性プレミアム) l.

  It follows that the total return expected from the ownership of an asset over a period is equal to its yield minus its carrying-cost plus its liquidity-premium, i.e. to q - c + l. That is to say, q - c + l is the own-rate of interest(自己利子率) of any commodity, where q, c and l are measured in terms of itself as the standard.

  It is characteristic of instrumental capital (eg. a machine) or of consumption capital (eg. a house) which is in use, that its yield should normally exceed its carrying-cost, whilst its liquidity-premium is probably negligible; of a stock of liquid goods or of surplus laid-up instrumental or consumption capital that it should incur a carrying-cost in terms of itself without any yield to set off against it(それを相殺する収益を産まないということである), the liquidity-premium in this case also being usually negligible as soon as stocks exceed a moderate level, though capable of being significant in special circumstances; and of money that its yield is nil, and its carrying-cost negligible, but its liquidity-premium substantial. Different commodities may, indeed, have differing degrees of liquidity-premium amongst themselves, and money may incur some degree of carrying-costs, eg. for safe custody. But it is an essential difference between money and all (or most) other assets that in the case of money its liquidity-premium much exceeds its carrying-cost, whereas in the case of other assets their carrying-cost much exceeds their liquidity-premium. Let us, for purposes of illustration, assume that on houses the yield is q1 and the carrying-cost and liquidity-premium negligible; that on wheat the carrying-cost is c2 and the yield and liquidity-premium negligible; and that on money the liquidity-premium is l3 and the yield and carrying-cost negligible. That is to say, q1 is the house-rate of interest, -c2 the wheat-rate of interest, and l3 the money-rate of interest.

To determine the relationships between the expected returns on different types of assets which are consistent with equilibrium, we must also know what the changes in relative values during the year are expected to be. Taking money (which need only be a money of account for this purpose, and we could equally well take wheat) as our standard of measurement, let the expected percentage appreciation (or depreciation) of houses be a1 and of wheat a2. ql, -c2 and l3 we have called the own-rates of interest of houses, wheat and money in terms of themselves as the standard of value; i.e. q1 is the house-rate of interest in terms of houses, -c2 is the wheat-rate of interest in terms of wheat, and l3 is the money-rate of interest in terms of money. It will also be useful to call a1 + ql, a2 - c2, and l3, which stand for the same quantities reduced to money as the standard of value, the house-rate of money-interest, the wheat-rate of money-interest and the money-rate of money-interest respectively. With this notation it is easy to see that the demand of wealth-owners will be directed to houses, to wheat or to money, according as a1 + q1 or a2 - c2, or l3, is greatest. Thus in equilibrium the demand-prices of houses and wheat in terms of money will be such that there is nothing to choose in the way of advantage between the alternatives; ― i.e. a1 + q1, a2 - c2 and l3 will be equal. The choice of the standard of value will make no difference to this result because a shift from one standard to another will change all the terms equally, i.e. by an amount equal to the expected rate of appreciation (or depreciation) of the new standard in terms of the old.

Now those assets of which the normal supply-price is less than the demand-price will be newly produced, and these will be those assets of which the marginal efficiency would be greater (on the basis of their normal supply-price) than the rate of interest (both being measured in the same standard of value whatever it is). As the stock of the assets, which begin by having a marginal efficiency at least equal to the rate of interest, is increased, their marginal efficiency (for reasons, sufficiently obvious, already given) tends to fall. Thus a point will come at which it no longer pays to produce them, unless the rate of interest falls pari passu. When there is no asset of which the marginal efficiency reaches the rate of interest, the further production of capital-assets will come to a standstill.

Let us suppose (as a mere hypothesis at this stage of the argument) that there is some asset (eg. money) of which the rate of interest is fixed (or declines more slowly as output increases than does any other commodity's rate of interest); how is the position adjusted? Since a1 + q1, a2 - c2 and l3, are necessarily equal, and since l3 by hypothesis is either fixed or falling more slowly than q1 or -c2, it follows that a1 and a2, must be rising. In other words, the present money-price of every commodity other than money tends to fall relatively to its expected future price. Hence, if q1 and -c2, continue to fall, a point comes at which it is not profitable to produce any of the commodities, unless the cost of production at some future date is expected to rise above the present cost by an amount which will cover the cost of carrying a stock produced now to the date of the prospective higher price.

  It is now apparent that our previous statement to the effect that it is the money-rate of interest which sets a limit to the rate of output, is not strictly correct. We should have said that it is that asset's rate of interest which declines most slowly as the stock of assets in general increases, which eventually knocks out the profitable production of each of the others, ― except in the contingency, just mentioned, of a special relationship between the present and prospective costs of production. As output increases, own-rates of interest decline to levels at which one asset after another falls below the standard of profitable production; ― until, finally, one or more own-rates of interest remain at a level which is above that of the marginal efficiency of any asset whatever.

  If by money we mean the standard of value, it is clear that it is not necessarily the money-rate of interest which makes the trouble. We could not get out of our difficulties (as some have supposed) merely by decreeing that wheat or houses shall be the standard of value instead of gold or sterling. For, it now appears that the same difficulties will ensue if there continues to exist any asset of which the own-rate of interest is reluctant to decline as output increases. It may be, for example, that gold will continue to fill this role in a country which has gone over to an inconvertible paper standard.
III

  In attributing, therefore, a peculiar significance to the money-rate of interest, we have been tacitly assuming that the kind of money to which we are accustomed has some special characteristics which lead to its own rate of interest in terms of itself as standard being more reluctant to fall as output increases than the own-rates of interest of any other assets in terms of themselves. Is this assumption justified? Reflection shows, I think, that the following peculiarities, which commonly characterise money as we know it, are capable of justifying it. To the extent that the established standard of value has these peculiarities, the summary statement, that it is the money-rate of interest which is the significant rate of interest, will hold good.

(i) The first characteristic which tends towards the above conclusion is the fact that money has, both in the long and in the short period, a zero, or at any rate a very small, elasticity of production, so far as the power of private enterprise is concerned, as distinct from the monetary authority; ― elasticity of production[2] meaning, in this context, the response of the quantity of labour applied to producing it to a rise in the quantity of labour which a unit of it will command. Money, that is to say, cannot be readily produced; ― labour cannot be turned on at will by entrepreneurs to produce money in increasing quantities as its price rises in terms of the wage-unit. In the case of an inconvertible managed currency this condition is strictly satisfied. But in the case of a gold-standard currency it is also approximately so, in the sense that the maximum proportional addition to the quantity of labour which can be thus employed is very small, except indeed in a country of which gold-mining is the major industry.

Now, in the case of assets having an elasticity of production, the reason why we assumed their own-rate of interest to decline was because we assumed the stock of them to increase as the result of a higher rate of output. In the case of money, however ― postponing, for the moment, our consideration of the effects of reducing the wage-unit or of a deliberate increase in its supply by the monetary authority ― the supply is fixed. Thus the characteristic that money cannot be readily produced by labour gives at once some prima facie presumption for the view that its own-rate of interest will be relatively reluctant to fall; whereas if money could be grown like a crop or manufactured like a motor-car, depressions would be avoided or mitigated because, if the price of other assets was tending to fall in terms of money, more labour would be diverted into the production of money; ― as we see to be the case in gold-mining countries, though for the world as a whole the maximum diversion in this way is almost negligible.

(ii) Obviously, however, the above condition is satisfied, not only by money, but by all pure rent-factors, the production of which is completely inelastic. A second condition, therefore, is required to distinguish money from other rent elements.

The second differentia of money is that it has an elasticity of substitution equal, or nearly equal, to zero; which means that as the exchange value of money rises there is no tendency to substitute some other factor for it; ― except, perhaps, to some trifling extent, where the money-commodity is also used in manufacture or the arts. This follows from the peculiarity of money that its utility is solely derived from its exchange-value, so that the two rise and fall pari passu, with the result that as the exchange value of money rises there is no motive or tendency, as in the case of rent-factors, to substitute some other factor for it.

Thus, not only is it impossible to turn more labour on to producing money when its labour-price rises, but money is a bottomless sink for purchasing power, when the demand for it increases, since there is no value for it at which demand is diverted ― as in the case of other rent-factors ― so as to slop over into a demand for other things.

The only qualification to this arises when the rise in the value of money leads to uncertainty as to the future maintenance of this rise; in which event, a1 and a2 are increased, which is tantamount to an increase in the commodity-rates of money-interest and is, therefore, stimulating to the output of other assets.

(iii) Thirdly, we must consider whether these conclusions are upset by the fact that, even though the quantity of money cannot be increased by diverting labour into producing it, nevertheless an assumption that its effective supply is rigidly fixed would be inaccurate. In particular, a reduction of the wage-unit will release cash from its other uses for the satisfaction of the liquidity-motive; whilst, in addition to this, as money-values fall, the stock of money will bear a higher proportion to the total wealth of the community.

  It is not possible to dispute on purely theoretical grounds that this reaction might be capable of allowing an adequate decline in the money-rate of interest. There are, however, several reasons, which taken in combination are of compelling force, why in an economy of the type to which we are accustomed it is very probable that the money-rate of interest will often prove reluctant to decline adequately:

(a) We have to allow, first of all, for the reactions of a fall in the wage-unit on the marginal efficiencies of other assets in terms of money; ― for it is the difference between these and the money-rate of interest with which we are concerned. If the effect of the fall in the wage-unit is to produce an expectation that it will subsequently rise again, the result will be wholly favourable. If, on the contrary, the effect is to produce an expectation of a further fall, the reaction on the marginal efficiency of capital may offset the decline in the rate of interest.[4]

(b) The fact that wages tend to be sticky in terms of money, the money-wage being more stable than the real wage, tends to limit the readiness of the wage-unit to fall in terms of money. Moreover, if this were not so, the position might be worse rather than better; because, if money-wages were to fall easily, this might often tend to create an expectation of a further fall with unfavourable reactions on the marginal efficiency of capital. Furthermore, if wages were to be fixed in terms of some other commodity, eg. wheat, it is improbable that they would continue to be sticky. It is because of money's other characteristics ― those, especially, which make it liquid ― that wages, when fixed in terms of it, tend to be sticky.[4]

(c) Thirdly, we come to what is the most fundamental consideration in this context, namely, the characteristics of money which satisfy liquidity-preference. For, in certain circumstances such as will often occur, these will cause the rate of interest to be insensitive, particularly below a certain figure,[5] even to a substantial increase in the quantity of money in proportion to other forms of wealth. In other words, beyond a certain point money's yield from liquidity does not fall in response to an increase in its quantity to anything approaching the extent to which the yield from other types of assets falls when their quantity is comparably increased.

  In this connection the low (or negligible) carrying-costs of money play an essential part. For if its carrying-costs were material, they would offset the effect of expectations as to the prospective value of money at future dates. The readiness of the public to increase their stock of money in response to a comparatively small stimulus is due to the advantages of liquidity (real or supposed) having no offset to contend with in the shape of carrying-costs mounting steeply with the lapse of time. In the case of a commodity other than money a modest stock of it may offer some convenience to users of the commodity. But even though a larger stock might have some attractions as representing a store of wealth of stable value, this would be offset by its carrying-costs in the shape of storage, wastage, etc. Hence, after a certain point is reached, there is necessarily a loss in holding a greater stock.

  In the case of money, however, this, as we have seen, is not so, ― and for a variety of reasons, namely, those which constitute money as being, in the estimation of the public, par excellence “liquid.” Thus those reformers, who look for a remedy by creating artificial carrying-costs for money through the device of requiring legal-tender currency to be periodically stamped at a prescribed cost in order to retain its quality as money, or in analogous ways, have been on the right track; and the practical value of their proposals deserves consideration.

 

The significance of the money-rate of interest arises, therefore, out of the combination of the characteristics that, through the working of the liquidity-motive, this rate of interest may be somewhat unresponsive to a change in the proportion which the quantity of money bears to other forms of wealth measured in money, and that money has (or may have) zero (or negligible) elasticities both of production and of substitution. The first condition means that demand may be predominantly directed to money, the second that when this occurs labour cannot be employed in producing more money, and the third that there is no mitigation at any point through some other factor being capable, if it is sufficiently cheap, of doing money's duty equally well. The only relief ― apart from changes in the marginal efficiency of capital ― can come (so long as the propensity towards liquidity is unchanged) from an increase in the quantity of money, or ― which is formally the same thing ― a rise in the value of money which enables a given quantity to provide increased money-services.

Thus a rise in the money-rate of interest retards the output of all the objects of which the production is elastic without being capable of stimulating the output of money (the production of which is, by hypothesis, perfectly inelastic). The money-rate of interest, by setting the pace for all the other commodity-rates of interest, holds back investment in the production of these other commodities without being capable of stimulating investment for the production of money, which by hypothesis cannot be produced. Moreover, owing to the elasticity of demand for liquid cash in terms of debts, a small change in the conditions governing this demand may not much alter the money-rate of interest, whilst (apart from official action) it is also impracticable, owing to the inelasticity of the production of money, for natural forces to bring the money-rate of interest down by affecting the supply side. In the case of an ordinary commodity, the inelasticity of the demand for liquid stocks of it would enable small changes on the demand side to bring its rate of interest up or down with a rush, whilst the elasticity of its supply would also tend to prevent a high premium on spot over forward delivery. Thus with other commodities left to themselves, “natural forces,” i.e. the ordinary forces of the market, would tend to bring their rate of interest down until the emergence of full employment had brought about for commodities generally the inelasticity of supply which we have postulated as a normal characteristic of money. Thus in the absence of money and in the absence ― we must, of course, also suppose ― of any other commodity with the assumed characteristics of money, the rates of interest would only reach equilibrium when there is full employment.

Unemployment develops, that is to say, because people want the moon; ― men cannot be employed when the object of desire (i.e. money) is something which cannot be produced and the demand for which cannot be readily choked off. There is no remedy but to persuade the public that green cheese is practically the same thing and to have a green cheese factory (i.e. a central bank) under public control.

  It is interesting to notice that the characteristic which has been traditionally supposed to render gold especially suitable for use as the standard of value, namely, its inelasticity of supply, turns out to be precisely the characteristic which is at the bottom of the trouble.

 

Our conclusion can be stated in the most general form (taking the propensity to consume as given) as follows. No further increase in the rate of investment is possible when the greatest amongst the own-rates of own-interest of all available assets is equal to the greatest amongst the marginal efficiencies of all assets, measured in terms of the asset whose own-rate of own-interest is greatest.

  In a position of full employment this condition is necessarily satisfied. But it may also be satisfied before full employment is reached, if there exists some asset, having zero (or relatively small) elasticities of production and substitution,[6] whose rate of interest declines more slowly, as output increases, than the marginal efficiencies of capital-assets measured in terms of it.
IV

We have shown above that for a commodity to be the standard of value is not a sufficient condition for that commodity's rate of interest to be the significant rate of interest. It is, however, interesting to consider how far those characteristics of money as we know it, which make the money-rate of interest the significant rate, are bound up with money being the standard in which debts and wages are usually fixed. The matter requires consideration under two aspects.

  In the first place, the fact that contracts are fixed, and wages are usually somewhat stable, in terms of money unquestionably plays a large part in attracting to money so high a liquidity-premium. The convenience of holding assets in the same standard as that in which future liabilities may fall due and in a standard in terms of which the future cost of living is expected to be relatively stable, is obvious. At the same time the expectation of relative stability in the future money-cost of output might not be entertained with much confidence(確信度) ff the standard of value were a commodity with a high elasticity of production. Moreover, the low carrying-costs of money as we know it play quite as large a part as a high liquidity-premium in making the money-rate of interest the significant rate. For what matters is the difference between the liquidity-premium and the carrying-costs; and in the case of most commodities, other than such assets as gold and silver and bank-notes, the carrying-costs are at least as high as the liquidity-premium ordinarily attaching to the standard in which contracts and wages are fixed, so that, even if the liquidity-premium now attaching to (e.g.) sterling-money were to be transferred to (eg.) wheat, the wheat-rate of interest would still be unlikely to rise above zero. It remains the case, therefore, that, whilst the fact of contracts and wages being fixed in terms of money considerably enhances the significance of the money-rate of interest, this circumstance is, nevertheless, probably insufficient by itself to produce the observed characteristics of the money-rate of interest.

The second point to be considered is more subtle. The normal expectation that the value of output will be more stable in terms of money than in terms of any other commodity, depends of course, not on wages being arranged in terms of money, but on wages being relatively sticky in terms of money. What, then, would the position be if wages were expected to be more sticky (i.e. more stable) in terms of some one or more commodities other than money, than in terms of money itself? Such an expectation requires, not only that the costs of the commodity in question are expected to be relatively constant in terms of the wage-unit for a greater or smaller scale of output both in the short and in the long period, but also that any surplus over the current demand at cost-price can be taken into stock without cost, i.e. that its liquidity-premium exceeds its carrying-costs (for, otherwise, since there is no hope of profit from a higher price, the carrying of a stock must necessarily involve a loss). If a commodity can be found to satisfy these conditions, then, assuredly, it might be set up as a rival to money. Thus it is not logically impossible that there should be a commodity in terms of which the value of output is expected to be more stable than in terms of money. But it does not seem probable that any such commodity exists.

  I conclude, therefore, that the commodity, in terms of which wages are expected to be most sticky, cannot be one whose elasticity of production is not least, and for which the excess of carrying-costs over liquidity-premium is not least. In other words, the expectation of a relative stickiness of wages in terms of money is a corollary of the excess of liquidity-premium over carrying-costs being greater for money than for any other asset.

Thus we see that the various characteristics, which combine to make the money-rate of interest significant, interact with one another in a cumulative fashion. The fact that money has low elasticities of production and substitution and low carrying-costs tends to raise the expectation that will be relatively stable; and this expectation enhances money's liquidity-premium and prevents the exceptional correlation between the money-rate of interest and the marginal efficiencies of other assets which might, if it could exist, rob the money-rate of interest of its sting.

Professor Pigou (with others) has been accustomed to assume that there is a presumption in favour of real wages being more stable than money-wages. But this could only be the case if there were a presumption in favour of stability of employment. Moreover, there is also the difficulty that wage-goods have a high carrying-cost. If, indeed, some attempt were made to stabilise real wages by fixing wages in terms of wage-goods, the effect could only be to cause a violent oscillation of money-prices. For every small fluctuation in the propensity to consume and the inducement to invest would cause money-prices to rush violently between zero and infinity. That money-wages should be more stable than real wages is a condition of the system possessing inherent stability.

Thus the attribution of relative stability to real wages is not merely a mistake in fact and experience. It is also a mistake in logic, if we are supposing that the system in view is stable, in the sense that small changes in the propensity to consume and the inducement to invest do not produce violent effects on prices.

V

As a footnote to the above, it may be worth emphasising what has been already stated above, namely, that “liquidity” and “carrying-costs” are both a matter of degree; and that it is only in having the former high relatively to the latter that the peculiarity of “money” consists.

Consider, for example, an economy in which there is no asset for which the liquidity-premium is always in excess of the carrying-costs; which is the best definition I can give of a so-called “non-monetary” economy. There exists nothing, that is to say, but particular consumables and particular capital equipments more or less differentiated according to the character of the consumables which they can yield up, or assist to yield up, over a greater or a shorter period of time; all of which, unlike cash, deteriorate or involve expense, if they are kept in stock, to a value in excess of any liquidity-premium which may attach to them.

  In such an economy capital equipments will differ from one another (a) in the variety of the consumables in the production of which they are capable of assisting, (b) in the stability of value of their output (in the sense in which the value of bread is more stable through time than the value of fashionable novelties), and (c) in the rapidity with which the wealth embodied in them can become “liquid”, in the sense of producing output, the proceeds of which can be re-embodied if desired in quite a different form.

  The owners of wealth will then weigh the lack of “liquidity” of different capital equipments in the above sense as a medium in which to hold wealth against the best available actuarial estimate of their prospective yields after allowing for risk. The liquidity-premium, it will be observed, is partly similar to the risk-premium, but partly different; ― the difference corresponding to the difference between the best estimates we can make of probabilities and the confidence with which we make them.[7] When we were dealing, in earlier chapters, with the estimation of prospective yield, we did not enter into detail as to how the estimation is made: and to avoid complicating the argument, we did not distinguish differences in liquidity from differences in risk proper. It is evident, however, that in calculating the own-rate of interest we must allow for both.

  There is, clearly, no absolute standard of “liquidity” but merely a scale of liquidity ― a varying premium of which account has to be taken, in addition to the yield of use and the carrying-costs, in estimating the comparative attractions of holding different forms of wealth. The conception of what contributes to “liquidity” is a partly vague one, changing from time to time and depending on social practices and institutions. The order of preference in the minds of owners of wealth in which at any given time they express their feelings about liquidity is, however, definite and is all we require for our analysis of the behaviour of the economic system.

  It may be that in certain historic environments the possession of land has been characterised by a high liquidity-premium in the minds of owners of wealth; and since land resembles money in that its elasticities of production and substitution may be very low,[8] it is conceivable that there have been occasions in history in which the desire to hold land has played the same role in keeping up the rate of interest at too high a level which money has played in recent times. It is difficult to trace this influence quantitatively owing to the absence of a forward price for land in terms of itself which is strictly comparable with the rate of interest on a money debt. We have, however, something which has, at times, been closely analogous, in the shape of high rates of interest on mortgages.[9] The high rates of interest from mortgages on land, often exceeding the probable net yield from cultivating the land, have been a familiar feature of many agricultural economies. Usury laws have been directed primarily against encumbrances of this character. And rightly so. For in earlier social organisations where long-term bonds in the modern sense were non-existent, the competition of a high interest-rate on mortgages may well have had the same effect in retarding the growth of wealth from current investment in newly produced capital-assets, as high interest rates on long-term debts have had in more recent times.

  That the world after several millennia of steady individual saving, is so poor as it is in accumulated capital-assets, is to be explained, in my opinion, neither by the improvident propensities of mankind, nor even by the destruction of war, but by the high liquidity-premiums formerly attaching to the ownership of land and now attaching to money. I differ in this from the older view as expressed by Marshall with an unusual dogmatic force in his Principles of Economics, p. 581: ―

  Everyone is aware that the accumulation of wealth is held in check, and the rate of interest so far sustained, by the preference which the great mass of humanity have for present over deferred gratifications, or, in other words, by their unwillingness to “wait”.

VI

  In my Treatise on Money I defined what purported to be a unique rate of interest, which I called the natural rate of interest ― namely, the rate of interest which, in the terminology of my Treatise, preserved equality between the rate of saving (as there defined) and the rate of investment. I believed this to be a development and clarification of Wicksell's “natural rate of interest”, which was, according to him, the rate which would preserve the stability of some, not quite clearly specified, price-level.

  I had, however, overlooked the fact that in any given society there is, on this definition, a different natural rate of interest for each hypothetical level of employment. And, similarly, for every rate of interest there is a level of employment for which that rate is the “natural” rate, in the sense that the system will be in equilibrium with that rate of interest and that level of employment. Thus it was a mistake to speak of the natural rate of interest or to suggest that the above definition would yield a unique value for the rate of interest irrespective of the level of employment. I had not then understood that, in certain conditions, the system could be in equilibrium with less than full employment.

  I am now no longer of the opinion that the concept of a “natural” rate of interest, which previously seemed to me a most promising idea, has anything very useful or significant to contribute to our analysis. It is merely the rate of interest which will preserve the status quo; and, in general, we have no predominant interest in the status quo as such.

  If there is any such rate of interest, which is unique and significant, it must be the rate which we might term the neutral rate of interest,[10] namely, the natural rate in the above sense which is consistent with full employment, given the other parameters of the system; though this rate might be better described, perhaps, as the optimum rate.

  The neutral rate of interest can be more strictly defined as the rate of interest which prevails in equilibrium when output and employment are such that the elasticity of employment as a whole is zero.[11]

  The above gives us, once again, the answer to the question as to what tacit assumption is required to make sense of the classical theory of the rate of interest. This theory assumes either that the actual rate of interest is always equal to the neutral rate of interest in the sense in which we have just defined the latter, or alternatively that the actual rate of interest is always equal to the rate of interest which will maintain employment at some specified constant level. If the traditional theory is thus interpreted, there is little or nothing in its practical conclusions to which we need take exception. The classical theory assumes that the banking authority or natural forces cause the market-rate of interest to satisfy one or other of the above conditions; and it investigates what laws will govern the application and rewards of the community's productive resources subject to this assumption. With this limitation in force, the volume of output depends solely on the assumed constant level of employment in conjunction with the current equipment and technique; and we are safely ensconced in a Ricardian world.

Author's Footnotes

[1]. This relationship was first pointed out by Mr. Sraffa, Economic Journal, March 1932, p. 50.

[2]. See Chapter 20.

[3]. This is a matter which will be examined in greater detail in Chapter 19 below.

[4]. If wages (and contracts) were fixed in terms of wheat, it might be that wheat would acquire some of money's liquidity-premium; ― we will return to this question in (IV) below.

[5]. See p. 172 above.

[6]. A zero elasticity is a more stringent condition than is necessarily required.

[7]. Cf. the footnote to p. 148 above.

[8]. The attribute of “liquidity” is by no means independent of the presence of these two characteristics. For it is unlikely that an asset, of which the supply can be easily increased or the desire for which can be easily diverted by a change in relative price, will possess the attribute of “liquidity” in the minds of owners of wealth. Money itself rapidly loses the attribute of “liquidity” if its future supply is expected to undergo sharp changes.

[9]. A mortgage and the interest thereon are, indeed, fixed in terms of money. But the fact that the mortgagor has the option to deliver the land itself in discharge of the debt ― and must so deliver it if he cannot find the money on demand ― has sometimes made the mortgage system approximate to a contract of land for future delivery against land for spot delivery. There have been sales of lands to tenants against mortgages effected by them, which, in fact, came very near to being transactions of this character.

[10]. This definition does not correspond to any of the various definitions of neutral money given by recent writers; though it may, perhaps, have some relation to the objective which these writers have had in mind.

[11]. Cf. Chapter 20 below.

 

Chapter 18. The General Theory of Employment Re-Stated
I

WE have now reached a point where we can gather together the threads of our argument. To begin with, it may be useful to make clear which elements in the economic system we usually take as given, which are the independent variables of our system and which are the dependent variables.

We take as given the existing skill and quantity of available labour, the existing quality and quantity of available equipment, the existing technique, the degree of competition, the tastes and habits of the consumer, the disutility of different intensifies of labour and of the activities of supervision and organisation, as well as the social structure including the forces, other than our variables set forth below, which determine the distribution of the national income. This does not mean that we assume these factors to be constant; but merely that, in this place and context, we are not considering or taking into account the effects and consequences of changes in them.

Our independent variables are, in the first instance, the propensity to consume, the schedule of the marginal efficiency of capital and the rate of interest, though, as we have already seen, these are capable of further analysis.

Our dependent variables are the volume of employment and the national income (or national dividend) measured in wage-units.

The factors, which we have taken as given, influence our independent variables, but do not completely determine them. For example, the schedule of the marginal efficiency of capital depends partly on the existing quantity of equipment which is one of the given factors, but partly on the state of long-term expectation which cannot be inferred from the given factors. But there are certain other elements which the given factors determine so completely that we can treat these derivatives as being themselves given. For example, the given factors allow us to infer what level of national income measured in terms of the wage-unit will correspond to any given level of employment; so that, within the economic framework which we take as given, the national income depends on the volume of employment, i.e. on the quantity of effort currently devoted to production, in the sense that there is a unique correlation between the two.[1] Furthermore, they allow us to infer the shape of the aggregate supply functions, which embody the physical conditions of supply, for different types of products; ― that is to say, the quantity of employment which will be devoted to production corresponding to any given level of effective demand measured in terms of wage-units. Finally, they furnish us with the supply function of labour (or effort); so that they tell us inter alia at what point the employment function[2] for labour as a whole will cease to be elastic.

The schedule of the marginal efficiency of capital depends, however, partly on the given factors and partly on the prospective yield of capital-assets of different kinds; whilst the rate of interest depends partly on the state of liquidity-preference (i.e. on the liquidity function) and partly on the quantity of money measured in terms of wage-units. Thus we can sometimes regard our ultimate independent variables as consisting of (1) the three fundamental psychological factors, namely, the psychological propensity to consume, the psychological attitude to liquidity and the psychological expectation of future yield from capital-assets, (2) the wage-unit as determined by the bargains reached between employers and employed, and (3) the quantity of money as determined by the action of the central bank; so that, if we take as given the factors specified above, these variables determine the national income (or dividend) and the quantity of employment. But these again would be capable of being subjected to further analysis, and are not, so to speak, our ultimate atomic independent elements.

The division of the determinants of the economic system into the two groups of given factors and independent variables is, of course, quite arbitrary from any absolute standpoint. The division must be made entirely on the basis of experience, so as to correspond on the one hand to the factors in which the changes seem to be so slow or so little relevant as to have only a small and comparatively negligible short-term influence on our quaesitum; and on the other hand to those factors in which the changes are found in practice to exercise a dominant influence on our quaesitum. Our present object is to discover what determines at any time the national income of a given economic system and (which is almost the same thing) the amount of its employment; which means in a study so complex as economics, in which we cannot hope to make completely accurate generalisations, the factors whose changes mainly determine our quaesitum. Our final task might be to select those variables which can be deliberately controlled or managed by central authority in the kind of system in which we actually live.
II

Let us now attempt to summarise the argument of the previous chapters; taking the factors in the reverse order to that in which we have introduced them.

There will be an inducement to push the rate of new investment to the point which forces the supply-price of each type of capital-asset to a figure which, taken in conjunction with its prospective yield, brings the marginal efficiency of capital in general to approximate equality with the rate of interest. That is to say, the physical conditions of supply in the capital-goods industries, the state of confidence concerning the prospective yield, the psychological attitude to liquidity and the quantity of money (preferably calculated in terms of wage-units) determine, between them, the rate of new investment.

But an increase (or decrease) in the rate of investment will have to carry with it an increase (or decrease) in the rate of consumption; because the behaviour of the public is, in general, of such a character that they are only willing to widen (or narrow) the gap between their income and their consumption if their income is being increased (or diminished). That is to say, changes in the rate of consumption are, in general, in the same direction (though smaller in amount) as changes in the rate of income. The relation between the increment of consumption which has to accompany a given increment of saving is given by the marginal propensity to consume. The ratio, thus determined, between an increment of investment and the corresponding increment of aggregate income, both measured in wage-units, is given by the investment multiplier.

Finally, if we assume (as a first approximation) that the employment multiplier is equal to the investment multiplier, we can, by applying the multiplier to the increment (or decrement) in the rate of investment brought about by the factors first described, infer the increment of employment.

An increment (or decrement) of employment is liable, however, to raise (or lower) the schedule of liquidity-preference; there being three ways in which it will tend to increase the demand for money, inasmuch as the value of output will rise when employment increases even if the wage-unit and prices (in terms of the wage-unit) are unchanged, but, in addition, the wage-unit itself will tend to rise as employment improves, and the increase in output will be accompanied by a rise of prices (in terms of the wage-unit) owing to increasing cost in the short period.

Thus the position of equilibrium will be influenced by these repercussions; and there are other repercussions also. Moreover, there is not one of the above factors which is not liable to change without much warning, and sometimes substantially. Hence the extreme complexity of the actual course of events. Nevertheless, these seem to be the factors which it is useful and convenient to isolate. If we examine any actual problem along the lines of the above schematism, we shall find it more manageable; and our practical intuition (which can take account of a more detailed complex of facts than can be treated on general principles) will be offered a less intractable material upon which to work.
III

The above is a summary of the General Theory. But the actual phenomena of the economic system are also coloured by certain special characteristics of the propensity to consume, the schedule of the marginal efficiency of capital and the rate of interest, about which we can safely generalise from experience, but which are not logically necessary.

  In particular, it is an outstanding characteristic of the economic system in which we live that, whilst it is subject to severe fluctuations in respect of output and employment, it is not violently unstable. Indeed it seems capable of remaining in a chronic condition of sub-normal activity for a considerable period without any marked tendency either towards recovery or towards complete collapse. (回復へも崩壊へも明確に進むことがない)Moreover, the evidence indicates that full, or even approximately full, employment is of rare and short-lived occurrence. Fluctuations may start briskly but seem to wear themselves out before they have proceeded to great extremes, and an intermediate situation which is neither desperate nor satisfactory is our normal lot. It is upon the fact that fluctuations tend to wear themselves out before proceeding to extremes and eventually to reverse themselves, that the theory of business cycles having a regular phase has been founded. The same thing is true of prices, which, in response to an initiating cause of disturbance, seem to be able to find a level at which they can remain, for the time being, moderately stable.

Now, since these facts of experience do not follow of logical necessity, one must suppose that the environment and the psychological propensities of the modern world must be of such a character as to produce these results. It is, therefore, useful to consider what hypothetical psychological propensities would lead to a stable system; and, then, whether these propensities can be plausibly ascribed, on our general knowledge of contemporary human nature, to the world in which we live.

The conditions of stability which the foregoing analysis suggests to us as capable of explaining the observed results are the following:

(i) The marginal propensity to consume is such that, when the output of a given community increases (or decreases) because more (or less) employment is being applied to its capital equipment, the multiplier relating the two is greater than unity but not very large.

(ii) When there is a change in the prospective yield of capital or in the rate of interest, the schedule of the marginal efficiency of capital will be such that the change in new investment will not be in great disproportion to the change in the former ; i.e. moderate changes in the prospective yield of capital or in the rate of interest will not be associated with very great changes in the rate of investment.

(iii) When there is a change in employment, money-wages tend to change in the same direction as, but not in great disproportion to, the change in employment; i.e. moderate changes in employment are not associated with very great chances in money-wages. This is a condition of the stability of prices rather than of employment.

(iv) We may add a fourth condition, which provides not so much for the stability of the system as for the tendency of a fluctuation in one direction to reverse itself in due course; namely, that a rate of investment, higher (or lower) than prevailed formerly, begins to react unfavourably (or favourably) on the marginal efficiency of capital if it is continued for a period which, measured in years, is not very large.

(i) Our first condition of stability, namely, that the multiplier, whilst greater than unity, is not very great, is highly plausible as a psychological characteristic of human nature. As real income increases, both the pressure of present needs diminishes and the margin over the established standard of life is increased; and as real income diminishes the opposite is true. Thus it is natural ― at any rate on the average of the community ― that current consumption should be expanded when employment increases) but by less than the full increment of real income; and that it should be diminished when employment diminishes, but by less than the full decrement of real income. Moreover, what is true of the average of individuals is likely to be also true of governments especially in an age when a progressive increase of unemployment will usually force the State to provide relief out of borrowed funds.

But whether or not this psychological law strikes the reader as plausible a priori, it is certain that experience would be extremely different from what it is if the law did not hold. For in that case an increase of investment, however small, would set moving a cumulative increase of effective demand until a position of full employment had been reached; while a decrease of investment would set moving a cumulative decrease of effective demand until no one at all was employed. Yet experience shows that we are generally in an intermediate position. It is not impossible that there may be a range within which instability does in fact prevail. But, if so, it is probably a narrow one, outside of which in either direction our psychological law must unquestionably hold good. Furthermore, it is also evident that the multiplier, though exceeding unity, is not, in normal circumstances, enormously large. For, if it were, a given change in the rate of investment would involve a great change (limited only by full or zero employment) in the rate of consumption.

(ii) Whilst our first condition provides that a moderate change in the rate of investment will not involve an indefinitely great change in the demand for consumption-goods our second condition provides that a moderate change in the prospective yield of capital-assets or in the rate of interest will not involve an indefinitely great change in the rate of investment. This is likely to be the case owing to the increasing cost of producing a greatly enlarged output from the existing equipment. If, indeed, we start from a position where there are very large surplus resources for the production of capital-assets, there may be considerable instability within a certain range; but this will cease to hold good as soon as the surplus is being largely utilised. Moreover, this condition sets a limit to the instability resulting from rapid changes in the prospective yield of capital-assets due to sharp fluctuations in business psychology or to epoch-making inventions ― though more, perhaps, in the upward than in the downward direction.

(iii) Our third condition accords with our experience of human nature. For although the struggle for money-wages is, as we have pointed out above, essentially a struggle to maintain a high relative wage, this struggle is likely, as employment increases, to be intensified in each individual case both because the bargaining position of the worker is improved and because the diminished marginal utility of his wage and his improved financial margin make him readier to run risks. Yet, all the same, these motives will operate within limits, and workers will not seek a much greater money-wage when employment improves or allow a very great reduction rather than suffer any unemployment at all.

But here again, whether or not this conclusion is plausible a priori, experience shows that some such psychological law must actually hold. For if competition between unemployed workers always led to a very great reduction of the money-wage, there would be a violent instability in the price-level. Moreover, there might be no position of stable equilibrium except in conditions consistent with full employment; since the wage-unit might have to fall without limit until it reached a point where the effect of the abundance of money in terms of the wage-unit on the rate of interest was sufficient to restore a level of full employment. At no other point could there be a resting-place.[3]

(iv) Our fourth condition, which is a condition not so much of stability as of alternate recession and recovery, is merely based on the presumption that capital-assets are of various ages, wear out with time and are not all very long-lived; so that if the rate of investment falls below a certain minimum level, it is merely a question of time (failing large fluctuations in other factors) before the marginal efficiency of capital rises sufficiently to bring about a recovery of investment above this minimum. And similarly, of course, if investment rises to a higher figure than formerly, it is only a question of time before the marginal efficiency of capital falls sufficiently to bring about a recession unless there are compensating changes in other factors.

For this reason, even those degrees of recovery and recession, which can occur within the limitations set by our other conditions of stability, will be likely, if they persist for a sufficient length of time and are not interfered with by changes in the other factors, to cause a reverse movement in the opposite direction, until the same forces as before again reverse the direction.

Thus our four conditions together are adequate to explain the outstanding features of our actual experience; ― namely, that we oscillate, avoiding the gravest extremes of fluctuation in employment and in prices in both directions, round an intermediate position appreciably below full employment and appreciably above the minimum employment a decline below which would endanger life.

But we must not conclude that the mean position thus determined by “natural” tendencies, namely, by those tendencies which are likely to persist, failing measures expressly designed to correct them, is, therefore, established by laws of necessity. The unimpeded rule of the above conditions is a fact of observation concerning the world as it is or has been, and not a necessary principle which cannot be changed.

Author's Footnotes

[1]. We are ignoring at this stage certain complications which arise when the employment functions of different products have different curvatures within the relevant range of employment. See Chapter 20 below.

[2]. Defined in Chapter 20 below.

[3]. The effects of changes in the wage-unit will be considered in detail in Chapter 19.

 

Book V  Money-Wages and Prices

Chapter 19. Changes in Money-Wages

I

  IT would have been an advantage if the effects of a change in money-wages could have been discussed in an earlier chapter. For the Classical Theory has been accustomed to rest the supposedly self-adjusting character of the economic system on an assumed fluidity of money-wages; and, when there is rigidity, to lay on this rigidity the blame of maladjustment.

  It was not possible, however, to discuss this matter fully until our own theory had been developed. For the consequences of a change in money-wages are complicated. A reduction in money-wages is quite capable in certain circumstances of affording a stimulus to output, as the classical theory supposes. My difference from this theory is primarily a difference of analysis; so that it could not be set forth clearly until the reader was acquainted with my own method.

The generally accepted explanation is, as I understand it, quite a simple one. It does not depend on roundabout repercussions, such as we shall discuss below. The argument simply is that a reduction in money-wages will cet. par. stimulate demand by diminishing the price of the finished product, and will therefore increase output and employment up to the point where the reduction which labour has agreed to accept in its money-wages is just offset by the diminishing marginal efficiency of labour as output (from a given equipment) is increased.

  In its crudest form, this is tantamount to assuming that the reduction in money-wages will leave demand unaffected. There may be some economists who would maintain that there is no reason why demand should be affected, arguing that aggregate demand depends on the quantity of money multiplied by the income-velocity of money and that there is no obvious reason why a reduction in money-wages would reduce either the quantity of money or its income-velocity. Or they may even argue that profits will necessarily go up because wages have gone down. But it would, I think, be more usual to degree that the reduction in money-wages may have some effect on aggregate demand through its reducing the purchasing power of some of the workers, but that the real demand of other factors, whose money incomes have not been reduced, will be stimulated by the fall in prices, and that the aggregate demand of the workers themselves will be very likely increased as a result of the increased volume of employment, unless the elasticity of demand for labour in response to changes in money-wages is less than unity. Thus in the new equilibrium there will be more employment than there would have been otherwise except, perhaps, in some unusual limiting case which has no reality in practice.

  It is from this type of analysis that I fundamentally differ; or rather from the analysis which seems to lie behind such observations as the above. For whilst the above fairly represents, I think, the way in which many economists talk and write, the underlying analysis has seldom been written down in detail.

  It appears, however, that this way of thinking is probably reached as follows. In any given industry we have a demand schedule for the product relating the quantities which can be sold to the prices asked; we have a series of supply schedules relating the prices which will be asked for the sale of different quantities on various bases of cost; and these schedules between them lead up to a further schedule which, on the assumption that other costs are unchanged (except as a result of the change in output), gives us the demand schedule for labour in the industry relating the quantity of employment to different levels of wages, the shape of the curve at any point furnishing the elasticity of demand for labour. This conception is then transferred without substantial modification to industry as a whole; and it is supposed, by a parity of reasoning, that we have a demand schedule for labour in industry as a whole relating the quantity of employment to different levels of wages. It is held that it makes no material difference to this argument whether it is in terms of money-wages or of real wages. If we are thinking in terms of money-wages, we must, of course, correct for changes in the value of money; but this leaves the general tendency of the argument unchanged, since prices certainly do not change in exact proportion to changes in money-wages.

  If this is the groundwork of the argument (and, if it is not, I do not know what the groundwork is), surely it is fallacious. For the demand schedules for particular industries can only be constructed on some fixed assumption as to the nature of the demand and supply schedules of other industries and as to the amount of the aggregate effective demand. It is invalid, therefore, to transfer the argument to industry as a whole unless we also transfer our assumption that the aggregate effective demand is fixed. Yet this assumption reduces the argument to an ignoratio elenchi. For, whilst no one would wish to deny the proposition that a reduction in money-wages accompanied by the same ggregate effective demand as before will be associated with an increase in employment, the precise question at issue is whether the reduction in money-wages will or will not be accompanied by the same aggregate effective demand as before measured in money, or, at any rate, by an aggregate effective demand which is not reduced in full proportion to the reduction in money-wages (i.e. which is somewhat greater measured in wage-units). But if the classical theory is not allowed to extend by analogy its conclusions in respect of a particular industry to industry as a whole, it is wholly unable to answer the question what effect on employment a reduction in money-wages will have. For it has no method of analysis wherewith to tackle the problem. Professor Pigou's Theory of Unemployment seems to me to get out of the Classical Theory all that can be got out of it; with the result that the book becomes a striking demonstration that this theory has nothing to offer, when it is applied to the problem of what determines the volume of actual employment as a whole.[1]

II

Let us, then, apply our own method of analysis to answering the problem. It falls into two parts. (1) Does a reduction in money-wages have a direct tendency, cet. par., to increase employment, “cet. par.” being taken to mean that the propensity to consume, the schedule of the marginal efficiency of capital and the rate of interest are the same as before for the community as a whole? And (2) does a reduction in money-wages have a certain or probable tendency to affect employment in a particular direction through its certain or probable repercussions on these three factors?

The first question we have already answered in the negative in the preceding chapters. For we have shown that the volume of employment is uniquely correlated with the volume of effective demand measured in wage-units, and that the effective demand, being the sum of the expected consumption and the expected investment, cannot change, if the propensity to consume, the schedule of marginal efficiency of capital and the rate of interest are all unchanged. If, without any change in these factors(これらの要素に変化がない場合には), the entrepreneurs were to increase employment as a whole, their proceeds will necessarily fall short of their supply-price.

Perhaps it will help to rebut the crude conclusion that a reduction in money-wages will increase employment “because it reduces the cost of production”, if we follow up the course of events on the hypothesis most favourable to this view, namely that at the outset entrepreneurs expect the reduction in money-wages to have this effect. It is indeed not unlikely that the individual entrepreneur, seeing his own costs reduced, will overlook at the outset the repercussions on the demand for his product and will act on the assumption that he will be able to sell at a profit a larger output than before. If, then, entrepreneurs generally act on this expectation, will they in fact succeed in increasing their profits? Only if the community's marginal propensity to consume is equal to unity, so that there is no gap between the increment of income and the increment of consumption; or if there is an increase in investment, corresponding to the gap between the increment of income and the increment of consumption, which will only occur if the schedule of marginal efficiencies of capital has increased relatively to the rate of interest. Thus the proceeds realised from the increased output will disappoint the entrepreneurs and employment will fall back again to its previous figure, unless the marginal propensity to consume is equal to unity or the reduction in money-wages has had the effect of increasing the schedule of marginal efficiencies of capital relatively to the rate of interest and hence the amount of investment. For if entrepreneurs offer employment on a scale which, if they could sell their output at the expected price, would provide the public with incomes out of which they would save more than the amount of current investment, entrepreneurs are bound to make a loss equal to the difference; and this will be the case absolutely irrespective of the level of money wages. At the best, the date of their disappointment can only be delayed for the interval during which their own investment in increased working capital is filling the gap.

Thus the reduction in money-wages will have no lasting tendency to increase employment except by virtue of its repercussions either on the propensity to consume for the community as a whole, or on the schedule of marginal efficiencies of capital, or on the rate of interest. There is no method of analysing the effect of a reduction in money-wages, except by following up its possible effects on these three factors.

The most important repercussions on these factors are likely, in practice, to be the following:

(1) A reduction of money-wages will somewhat reduce prices. It will, therefore, involve some redistribution of real income (a) from wage-earners to other factors entering into marginal prime-cost whose remuneration has not been reduced, and (b) from entrepreneurs to rentiers to whom a certain income fixed in terms of money has been guaranteed.

What will be the effect of this redistribution on the propensity to consume for the community as a whole? The transfer from wage-earners to other factors is likely to diminish the propensity to consume. The effect of the transfer from entrepreneurs to rentiers is more open to doubt. But if rentiers represent on the whole the richer section of the community and those whose standard of life is least flexible, then the effect of this also will be unfavourable. What the net result will be on a balance of considerations, we can only guess. Probably it is more likely to be adverse than favourable.

(2) If we are dealing with an unclosed system, and the reduction of money-wages is a reduction relatively to money-wages abroad when both are reduced to a common unit, it is evident that the change will be favourable to investment, since it will tend to increase the balance of trade. This assumes, of course, that the advantage is not offset by a change in tariffs, quotas, etc. The greater strength of the traditional belief in the efficacy of a reduction in money-wages as a means of increasing employment in Great Britain, as compared with the United States, is probably attributable to the latter being, comparatively with ourselves, a closed system.

(3) In the case of an unclosed system, a reduction of money-wages, though it increases the favourable balance of trade, is likely to worsen the terms of trade. Thus there will be a reduction in real incomes, except in the case of the newly employed, which may tend to increase the propensity to consume.

(4) If the reduction of money-wages is expected to be a reduction relatively to money-wages in the future, the change will be favourable to investment, because as we have seen above, it will increase the marginal efficiency of capital; whilst for the same reason it may be favourable to consumption. If, on the other hand, the reduction leads to the expectation, or even to the serious possibility, of a further wage-reduction in prospect, it will have precisely the opposite effect. For it will diminish the marginal efficiency of capital and will lead to the postponement both of investment and of consumption.

(5) The reduction in the wages-bill, accompanied by some reduction in prices and in money-incomes generally, will diminish the need for cash for income and business purposes; and it will therefore reduce pro tanto the schedule of liquidity-preference for the community as a whole. Cet. par. this will reduce the rate of interest and thus prove favourable to investment. In this case, however, the effect of expectation concerning the future will be of an opposite tendency to those just considered under (4). For, if wages and prices are expected to rise again later on, the favourable reaction will be much less pronounced in the case of long-term loans than in that of short-term loans. If, moreover, the reduction in wages disturbs political confidence by causing popular discontent, the increase in Liquidity-preference due to this cause may more than offset the release of cash from the active circulation.

(6) Since a special reduction of money-wages is always advantageous to an individual entrepreneur or industry, a general reduction (though its actual effects are different) may also produce an optimistic tone in the minds of entrepreneurs, which may break through a vicious circle of unduly pessimistic estimates of the marginal efficiency of capital and set things moving again on a more normal basis of expectation. On the other hand, if the workers make the same mistake as their employers about the effects of a general reduction, labour troubles may offset this favourable factor; apart from which, since there is, as a rule, no means of securing a simultaneous and equal reduction of money-wages in all industries, it is in the interest of all workers to resist a reduction in their own particular case. In fact, a movement by employers to revise money-wage bargains downward will be much more strongly resisted than a gradual and automatic lowering of real wages as a result of rising prices.

(7) On the other hand, the depressing influence on entrepreneurs of their greater burden of debt may partly offset any cheerful reactions from the reduction of wages. Indeed if the fall of wages and prices goes far, the embarrassment of those entrepreneurs who are heavily indebted may soon reach the point of insolvency, ― with severely adverse effects on investment. Moreover the effect of the lower price-level on the real burden of the National Debt and hence on taxation is likely to prove very adverse to business confidence.

This is not a complete catalogue of all the possible reactions of wage reductions in the complex real world. But the above cover, I think, those which are usually the most important.

  If, therefore, we restrict our argument to the case of a closed system, and assume that there is nothing to be hoped, but if anything the contrary, from the repercussions of the new distribution of real incomes on the community's propensity to spend, it follows that we must base any hopes of favourable results to employment from a reduction in money-wages mainly on an improvement in investment due either to an increased marginal efficiency of capital under (4) or a decreased rate of interest under (5). Let us consider these two possibilities in further detail.

The contingency, which is favourable to an increase in the marginal efficiency of capital, is that in which money-wages are believed to have touched bottom, so that further changes are expected to be in the upward direction. The most unfavourable contingency is that in which money-wages are slowly sagging downwards and each reduction in wages serves to diminish confidence in the prospective maintenance of wages. When we enter on a period of weakening effective demand, a sudden large reduction of money-wages to a level so low that no one believes in its indefinite continuance would be the event most favourable to a strengthening of effective demand. But this could only be accomplished by administrative decree and is scarcely practical politics under a system of free wage-bargaining. On the other hand, it would be much better that wages should be rigidly fixed and deemed incapable of material changes, than that depressions should be accompanied by a gradual downward tendency of money-wages, a further moderate wage reduction being expected to signalize(はっきり示す) each increase of, say, 1 per cent. in the amount of unemployment. For example, the effect of an expectation that wages are going to sag by, say, 2 per cent. in the coming year will be roughly equivalent to the effect of a rise of 2 per cent. in the amount of interest payable for the same period. The same observations apply mutatis mutandis to the case of a boom.

  It follows that with the actual practices and institutions of the contemporary world it is more expedient to aim at a rigid money-wage policy than at a flexible policy responding by easy stages to changes in the amount of unemployment; ― so far, that is to say, as the marginal efficiency of capital is concerned. But is this conclusion upset when we turn to the rate of interest?

  It is, therefore, on the effect of a falling wage- and price-level on the demand for money that those who believe in the self-adjusting quality of the economic system must rest the weight of their argument; though I am not aware that they have done so. If the quantity of money is itself a function of the wage- and price-level, there is indeed, nothing to hope in this direction. But if the quantity of money is virtually fixed, it is evident that its quantity in terms of wage-units can be indefinitely increased by a sufficient reduction in money-wages; and that its quantity in proportion to incomes generally can be largely increased, the limit to this increase depending on the proportion of wage-cost to marginal prime-cost and on the response of other elements of marginal prime-cost to the falling wage-unit.

We can, therefore, theoretically at least, produce precisely the same effects on the rate of interest by reducing wages, whilst leaving the quantity of money unchanged, that we can produce by increasing the quantity of money whilst leaving the level of wages unchanged. It follows that wage reductions, as a method of securing full employment, are also subject to the same limitations as the method of increasing the quantity of money. The same reasons as those mentioned above, which limit the efficacy of increases in the quantity of money as a means of increasing investment to the optimum figure, apply mutatis mutandis to wage reductions. Just as a moderate increase in the quantity of money may exert an inadequate influence over the long-term rate of interest, whilst an immoderate increase may offset its other advantages by its disturbing effect on confidence; so a moderate reduction in money-wages may prove inadequate, whilst an immoderate reduction might shatter confidence even if it were practicable.

There is, therefore, no ground for the belief that a flexible wage policy is capable of maintaining a state of continuous full employment; ― any more than for the belief than an open-market monetary policy is capable, unaided, of achieving this result. The economic system cannot be made self-adjusting along these lines.

  If, indeed, labour were always in a position to take action (and were to do so), whenever there was less than full employment, to reduce its money demands by concerted action to whatever point was required to make money so abundant relatively to the wage-unit that the rate of interest would fall to a level compatible with full employment, we should, in effect, have monetary management by the Trade Unions, aimed at full employment, instead of by the banking system.

Nevertheless while a flexible wage policy and a flexible money policy come, analytically, to the same thing, inasmuch as they are alternative means of changing the quantity of money in terms of wage-units, in other respects there is, of course, a world of difference between them. Let me briefly recall to the reader's mind the three outstanding considerations.

(i) Except in a socialised community where wage-policy is settled by decree, there is no means of securing uniform wage reductions for every class of labour. The result can only be brought about by a series of gradual, irregular changes, justifiable on no criterion of social justice or economic expediency, and probably completed only after wasteful and disastrous struggles, where those in the weakest bargaining position will suffer relatively to the rest. A change in the quantity of money, on the other hand, is already within the power of most governments by open-market policy or analogous measures. Having regard to human nature and our institutions, it can only be a foolish person who would prefer a flexible wage policy to a flexible money policy, unless he can point to advantages from the former which are not obtainable from the latter. Moreover, other things being equal, a method which it is comparatively easy to apply should be deemed preferable to a method which is probably so difficult as to be impracticable.

(ii) If money-wages are inflexible, such changes in prices as occur (i.e. apart from “administered “ or monopoly prices which are determined by other considerations besides marginal cost) will mainly correspond to the diminishing marginal productivity of the existing equipment as the output from it is increased. Thus the greatest practicable fairness will be maintained between labour and the factors whose remuneration is contractually fixed in terms of money, in particular the rentier class and persons with fixed salaries on the permanent establishment of a firm, an institution or the State. If important classes are to have their remuneration fixed in terms of money in any case, social justice and social expediency are best served if the remunerations of all factors are somewhat inflexible in terms of money. Having regard to the large groups of incomes which are comparatively inflexible in terms of money, it can only be an unjust person who would prefer a flexible wage policy to a flexible money policy, unless he can point to advantages from the former which are not obtainable from the latter.

(iii) The method of increasing the quantity of money in terms of wage-units by decreasing the wage-unit increases proportionately the burden of debt; whereas the method of producing the same result by increasing the quantity of money whilst leaving the wage-unit unchanged has the opposite effect. Having regard to the excessive burden of many types of debt, it can only be an inexperienced person who would prefer the former.

(iv) If a sagging rate of interest has to be brought about by a sagging wage-level, there is, for the reasons given above, a double drag on the marginal efficiency of capital and a double reason for putting off investment and thus postponing recovery.

III

  It follows, therefore, that if labour were to respond to conditions of gradually diminishing employment by offering its services at a gradually diminishing money-wage, this would not, as a rule, have the effect of reducing real wages and might even have the effect of increasing them, through its adverse influence on the volume of output. The chief result of this policy would be to cause a great instability of prices, so violent perhaps as to make business calculations futile in an economic society functioning after the manner of that in which we live. To suppose that a flexible wage policy is a right and proper adjunct of a system which on the whole is one of laissez-faire, is the opposite of the truth. It is only in a highly authoritarian society, where sudden, substantial, all-round changes could be decreed that a flexible wage-policy could function with success. One can imagine it in operation in Italy, Germany or Russia, but not in France, the United States or Great Britain.

  If, as in Australia, an attempt were made to fix real wages by legislation., then there would be a certain level of employment corresponding to that level of real wages; and the actual level of employment would, in a closed system, oscillate violently between that level and no employment at all, according as the rate of investment was or was not below the rate compatible with that level; whilst prices would be in unstable equilibrium when investment was at the critical level, racing to zero whenever investment was below it, and to infinity whenever it was above it. The element of stability would have to be found, if at all, in the factors controlling the quantity of money being so determined that there always existed some level of money-wages at which the quantity of money would be such as to establish a relation between the rate of interest and the marginal efficiency of capital which would maintain investment at the critical level. In this event employment would be constant (at the level appropriate to the legal real wage) with money-wages and prices fluctuating rapidly in the degree just necessary to maintain this rate of investment at the appropriate figure. In the actual case of Australia, the escape was found, partly of course in the inevitable inefficacy of the legislation to achieve its object, and partly in Australia not being a closed system, so that the level of money-wages was itself a determinant of the level of foreign investment and hence of total investment, whilst the terms of trade were an important influence on real wages.

  In the light of these considerations I am now of the opinion that the maintenance of a stable general level of money-wages is, on a balance of considerations, the most advisable policy for a closed system; whilst the same conclusion will hold good for an open system, provided that equilibrium with the rest of the world can be secured by means of fluctuating exchanges. There are advantages in some degree of flexibility in the wages of particular industries so as to expedite transfers from those which are relatively declining to those which are relatively expanding. But the money-wage level as a whole should be maintained as stable as possible, at any rate in the short period.

This policy will result in a fair degree of stability in the price-level;-greater stability, at least, than with a flexible wage policy. Apart from “administered” or monopoly prices, the price-level will only change in the short period in response to the extent that changes in the volume of employment affect marginal prime-costs; whilst in the long period they will only change in response to changes in the cost of production due to new technique and new or increased equipment.

  It is true that, if there are, nevertheless, large fluctuations in employment, substantial fluctuations in the price-level will accompany them. But the fluctuations will be less, as I have said above, than with a flexible wage policy.

Thus with a rigid wage policy the stability of prices will be bound up in the short period with the avoidance of fluctuations in employment. In the long period, on the other hand, we are still left with the choice between a policy of allowing prices to fall slowly with the progress of technique and equipment whilst keeping wages stable, or of allowing wages to rise slowly whilst keeping prices stable. On the whole my preference is for the latter alternative, on account of the fact that it is easier with an expectation of higher wages in future to keep the actual level of employment within a given range of full employment than with an expectation of lower wages in future, and on account also of the social advantages of gradually diminishing the burden of debt, the greater ease of adjustment from decaying to growing industries, and the psychological encouragement likely to be felt from a moderate tendency for money-wages to increase. But no essential point of principle is involved, an it would lead me beyond the scope of my present purpose to develop in detail the arguments on either side.

Author's Footnotes

[1]. In an appendix to this chapter Professor Pigou's Theory of Unemployment is criticised in detail.

 

Appendix to Chapter 19. Professor Pigou's “Theory of Unemployment”

第19章の付録、ピグー教授の『失業の理論』

PROFESSOR PIGOU in his Theory of Unemployment makes the volume of employment to depend on two fundamental factors, namely (1) the real rates of wages for which workpeople stipulate(要求する), and (2) the shape of the Real Demand Function for Labour(実質需要関数). The central sections of his book are concerned with determining the shape of the latter function. The fact that workpeople in fact stipulate, not for a real rate of wages, but for a money-rate, is not ignored; but, in effect, it is assumed that the actual money-rate of wages divided by the price of wage-goods can be taken to measure the real rate demanded.

ピグー教授は『失業理論』のなかで雇用量は二つの基本的な要因に左右されると言っている。その(1)は労働者たちが要求する実質賃金率であり、その(2) が実質労働需要関数であると。彼の本の中心部分はこの関数の形を決めることに費やされている。労働者側が実際に要求するのは実質賃金率ではなく、名目賃金 率であることは無視されてはいない。しかし、要するに、実際の名目賃金を賃金財の価格で割った値をもって、要求されている実質賃金率と見なすことが出来る としている。

The equations which, as he says, “form the starting point of the enquiry” into the Real Demand Function for Labour are given in his Theory of Unemployment, p. 90. Since the tacit assumptions, which govern the application of his analysis, slip in near the outset(初め) of his argument, I will summarise his treatment(議論) up to the crucial point.

実質労働需要関数に対する彼の言う「研究の出発点」となる方程式は、彼の『失業理論』の90頁に出ている。彼の分析を支配している暗黙の前提が彼の議論のごく最初のところに忍び込んでいるので、重要な点までの彼の議論を要約してみたい。

Professor Pigou divides industries into those “engaged in making wage-goods at home and in making exports the sale of which creates claims to wage-goods abroad(輸出品の販売によって海外の賃金財を購入する権利が生まれる)” and the “other” industries: which it is convenient to call the wage-goods industries and the non-wage-goods industries respectively.

ピグー教授は産業を「国内で賃金財を作る産業と輸出品を作る産業(その販売の御陰で海外の賃金剤を買う権利が生まれる)と他の産業」に分けている。これを便宜上、賃金財産業と非賃金財産業と呼ぶことにする。

He supposes x men to be employed in the former and y men in the latter. The output in value of wage-goods of the x men he calls F(x); and the general rate of wages F'(x).

彼は賃金財産業にx人が雇われ非賃金財産業にy人が雇われているとする。そしてx人の産出量を賃金財の価値で表したものを彼はF(x)(=主要費用)とし、全体的な賃金率をF'(x)(=限界賃金費用=限界主要費用)としている。

This, though he does not stop to mention it, is tantamount to assuming that marginal wage-cost is equal to marginal prime-cost.[1]

ピグー教授はわざわざ言及していないが、これは限界賃金費用が限界主要費用と一致すると想定しているに等しい。

Further, he assumes that x + y = φ(x), i.e. that the number of men employed in the wage-goods industries is a function of total employment.

さらに彼は x+y = φ(x)として、賃金財産業に雇用された人の数が総雇用関数であると考える。

He then shows that the elasticity of the real demand for labour in the aggregate (which gives us the shape of our quaesitum, namely the Real Demand Function for Labour) can be written

Er = (φ'(x)/φ(x)) . (F'(x)/F''(x))

それから彼は「総計としての労働の実質需要の弾力性」(これは我々が求める実質労働需要関数の形そのものである)は次の式で表わせるという。

Er = (φ'(x)/φ(x))×(F'(x)/F''(x))(=雇用の変化率÷限界賃金の変化率)

So far as notation goes, there is no significant difference between this and my own modes of expression. In so far as we can identify Professor Pigou's wage-goods with my consumption-goods, and his “other goods” with my investment-goods, it follows that his (F(x)/F'(x)), being the value of the output of the wage-goods industries in terms of the wage-unit, is the same as my Cw.

記号に関する限り、これは私の表記法と大きな違いはない。ピグー教授の賃金財と私の消費財を、彼の他の財を私の投資財に等しいとみなせるなら、単位賃金あたりの賃金財産業の産出物の価値である彼のF(x)/F'(x)は私のCwと等しい。

Furthermore, his function φ is (subject to the identification of wage-goods with consumption-goods) a function of what I have called above the employment multiplier k'. For

Δx = k'Δy ,

so that

φ'(x) = 1 + (1/k') .

さらに、彼の関数φは(賃金財を消費財と同じとすると)私が上記で雇用定数k'と呼んだものの関数である。というのは、

Δx=k'Δy

なので、(φ(x)=x+y、φ'(x)=1+Δy/Δx、Δy/Δx=1/k'だから)

φ'(x)=1+(1/k') となる。

Thus Professor Pigou's “elasticity of the real demand for labour in the aggregate” is a concoction similar to some of my own, depending partly on the physical and technical conditions in industry (as given by his function F) and partly on the propensity to consume wage-goods (as given by his function φ); provided always that we are limiting ourselves to the special case where marginal labour-cost is equal to marginal prime-cost.

このように、ピグー教授の「総計としての労働の実質需要の弾力性」は私のものに似た作りで、一部は産業の物理的かつ技術的条件(彼の関数Fによって与えら れる)に依存し、一部は賃金財の消費性向(彼の関数φによって与えられる)に依存している。もちろん、これは限界労働コストが限界主要費用に等しいという 特別な場合に限定した場合のことである。

To determine the quantity of employment, Professor Pigou then combines with his “real demand for labour”, a supply function for labour. He assumes that this is a function of the real wage and of nothing else. But, as he has also assumed that the real wage is a function of the number of men x who are employed in the wage-goods industries, this amounts to assuming that the total supply of labour at the existing real wage is a function of x and of nothing else. That is to say, n = χ(x), where n is the supply of labour available at a real wage F'(x).

次に、ピグー教授は雇用量を決定するために、彼の「労働の実質需要」と労働の供給関数を組み合わせている。この労働の供給関数を彼は実質賃金だけの関数で あると想定している。しかし、彼はまた実質賃金は賃金財産業に雇われている人間の数xの関数であるとも想定している。ということは、現行実質賃金財におけ る総労働供給はxだけの関数であるということになる。つまり、nを実質賃金F'(x)において利用可能な労働供給とすると、n= χ(x)であるということである。

Thus, cleared of all complication, Professor Pigou's analysis amounts to an attempt to discover the volume of actual employment from the equations

x + y = φ(x) and n = χ(x) .

こうして複雑な要素を取り除いていくと、ピグー教授の分析は次の2つの方程式

x+y = φ(x) と n=χ(x) から現実の雇用量を見つける試みだと言っていい。

But there are here three unknowns and only two equations. It seems clear that he gets round this difficulty by taking n = x + y. This amounts, of course, to assuming that there is no involuntary unemployment in the strict sense, i.e. that all labour available at the existing real wage is in fact employed. In this case x has the value which satisfies the equation

φ(x) = χ(x) ;

and when we have thus found that the value of x is equal to (say) n1, y must be equal to χ(n1) - n1, and total employment n is equal to χ(n1).

しかし、ここには三つの未知数があるのに二つの方程式しかない。この難問を回避するために彼がn=x+yとしていることは明らかである。これは厳密な意味 での「非自発的失業」が存在せず、現行実質賃金によって利用出来る全ての労働力が実際に雇用されている、と想定することになる。この場合、xは次の方程式 を満たす値を持つ。
φ(x)=χ(x)

そしてxの値を仮にn1とすると、yはχ(n1)ーn1と等しくなり、総雇用nはχ(n1)と等しくなる。

  It is worth pausing for a moment to consider what this involves. It means that, if the supply function of labour changes, more labour being available at a given real wage (so that n1+dn1 is now the value of x which satisfies the equation φ(x) =χ(x)), the demand for the output of the non-wage-goods industries is such that employment in these industries is bound to increase by just the amount which will preserve equality between φ(n1 + dn1) and χ(n1+dn1). The only other way in which it is possible for aggregate employment to change is through a modification of the propensity to purchase wage-goods and non-wage-goods respectively such that there is an increase of y accompanied by a greater decrease of x.

ここでしばらく立ち止まってこの事の意味を考えてみよう。

The assumption that n = x + y means, of course, that labour is always in a position to determine its own real wage. Thus, the assumption that labour is in a position to determine its own real wage, means that the demand for the output of the non-wage-goods industries obeys the above laws. In other words, it is assumed that the rate of interest always adjusts itself to the schedule of the marginal efficiency of capital in such a way as to preserve full employment. Without this assumption Professor Pigou's analysis breaks down and provides no means of determining what the volume of employment will be. It is, indeed, strange that Professor Pigou should have supposed that he could furnish a theory of unemployment which involves no reference at all to changes in the rate of investment (i.e. to changes in employment in the non-wage-goods industries) due, not to a change in the supply function of labour, but to changes in (e.g.) either the rate of interest or the state of confidence.

His title the “Theory of Unemployment” is, therefore, something of a misnomer. His book is not really concerned with this subject. It is a discussion of how much employment there will be, given the supply function of labour, when the conditions for full employment are satisfied. The purpose of the concept of the elasticity of the real demand for labour in the aggregate is to show by how much full employment will rise or fall corresponding to a given shift in the supply function of labour. Or ― alternatively and perhaps better ― we may regard his book as a non-causative investigation into the functional relationship which determines what level of real wages will correspond to any given level of employment. But it is not capable of telling us what determines the actual level of employment; and on the problem of involuntary unemployment it has no direct bearing.

  If Professor Pigou were to deny the possibility of involuntary unemployment in the sense in which I have defined it above, as, perhaps, he would, it is still difficult to see how his analysis could be applied. For his omission to discuss what determines the connection between x and y, i.e. between employment in the wage-goods and non-wage-goods industries respectively, still remains fatal.

Moreover, he agrees that within certain limits labour in fact often stipulates, not for a given real wage, but for a given money-wage. But in this case the supply function of labour is not a function of F'(x) alone but also of the money-price of wage-goods; ― with the result that the previous analysis breaks down and an additional factor has to be introduced, without there being an additional equation to provide for this additional unknown. The pitfalls of a pseudo-mathematical method, which can make no progress except by making everything a function of a single variable and assuming that all the partial differentials vanish, could no& inserted by FC2 system