The General Theory of 雇用, 利益／興味 and Money
一時期／支部 14
I
What is the classical theory of the 率 of 利益／興味? It is something upon which we have all been brought up and which we have 受託するd without much reserve until recently. Yet I find it difficult to 明言する／公表する it 正確に or to discover an explicit account of it in the 主要な treatises of the modern classical school.
It is 公正に／かなり （疑いを）晴らす, however, that this tradition has regarded the 率 of 利益／興味 as the factor which brings the 需要・要求する for 投資 and the 乗り気 to save into equilibrium with one another. 投資 代表するs the 需要・要求する for investible 資源s and saving 代表するs the 供給（する）, whilst the 率 of 利益／興味 is the 'price' of investible 資源s at which the two are equated. Just as the price of a 商品／必需品 is やむを得ず 直す／買収する，八百長をするd at that point where the 需要・要求する for it is equal to the 供給（する）, so the 率 of 利益／興味 やむを得ず comes to 残り／休憩（する） under the play of market 軍隊s at the point where the 量 of 投資 at that 率 of 利益／興味 is equal to the 量 of saving at that 率.
The above is not to be 設立する in Marshall's 原則s 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 に引き続いて passage from his 原則s: '利益／興味, 存在 the price paid for the use of 資本／首都 in any market, tends に向かって an equilibrium level such that the aggregate 需要・要求する for 資本／首都 in that market, at that 率 of 利益／興味, is equal to the aggregate 在庫／株 来たるべき at that 率'. Or again in Professor Cassel's Nature and Necessity of 利益／興味 it is explained that 投資 構成するs the '需要・要求する for waiting' and saving the '供給（する） of waiting', whilst 利益／興味 is a 'price' which serves, it is 暗示するd, to equate the two, though here again I have not 設立する actual words to 引用する. 一時期／支部 vi of Professor Carver's 配当 of Wealth 明確に 想像するs 利益／興味 as the factor which brings into equilibrium the ごくわずかの disutility of waiting with the ごくわずかの 生産性 of 資本／首都. Sir Alfred Flux (経済的な 原則s, p. 95) 令状s: 'If there is 司法（官） in the 論争s of our general discussion, it must be 認める that an (a)自動的な／(n)自動拳銃 調整 takes place between saving and the 適切な時期s for 雇うing 資本／首都 profitably. . . Saving will not have 越えるd its 可能性s of usefulness. . . so long as the 率 of 逮捕する 利益／興味 is in 超過 of 無.' Professor Taussig (原則s, vol. ii. p. 29) draws a 供給（する） curve of saving and a 需要・要求する curve 代表するing 'the 減らすing productiveness of the several instalments of 資本／首都', having 以前 明言する／公表するd (p.20) that 'the 率 of 利益／興味 settles at a point where the ごくわずかの 生産性 of 資本／首都 十分であるs to bring out the ごくわずかの instalment of saving'. Walras, in 虫垂 I (III) of his Éléments d'économie pure, where he 取引，協定s with 'l'échange d'épargnes contre capitaux neufs', argues expressly that, corresponding to each possible 率 of 利益／興味, there is a sum which individuals will save and also a sum which they will 投資する in new 資本／首都 資産s, that these two aggregates tend to equality with one another, and that the 率 of 利益／興味 is the variable which brings them to equality; so that the 率 of 利益／興味 is 直す／買収する，八百長をするd at the point where saving, which 代表するs the 供給（する） of new 資本／首都, is equal to the 需要・要求する for it. Thus he is 厳密に in the classical tradition.
Certainly the ordinary man¾銀行業者, civil servant or 政治家，政治屋¾brought up on the 伝統的な theory, and the trained 経済学者 also, has carried away with him the idea that whenever an individual 成し遂げるs an 行為／法令／行動する of saving he has done something which automatically brings 負かす／撃墜する the 率 of 利益／興味, that this automatically 刺激するs the 生産（高） of 資本／首都, and that the 落ちる in the 率 of 利益／興味 is just so much as is necessary to 刺激する the 生産（高） of 資本／首都 to an extent which is equal to the increment of saving; and, その上の, that this is a self-regulatory 過程 of 調整 which takes place without the necessity for any special 介入 or grandmotherly care on the part of the 通貨の 当局. 類似して¾and this is an even more general belief, even to-day¾each 付加 行為／法令／行動する of 投資 will やむを得ず raise the 率 of 利益／興味, if it is not 相殺する by a change in the 準備完了 to save.
Now the 分析 of the previous 一時期／支部s will have made it plain that this account of the 事柄 must be erroneous. In tracing to its source the 推論する／理由 for the difference of opinion, let us, however, begin with the 事柄s which are agreed.
Unlike the neo-classical school, who believe that saving and 投資 can be 現実に unequal, the classical school proper has 受託するd the 見解（をとる） that they are equal. Marshall, for example, surely believed, although he did not expressly say so, that aggregate saving and aggregate 投資 are やむを得ず equal. Indeed, most members of the classical school carried this belief much too far; since they held that every 行為／法令／行動する of 増加するd saving by an individual やむを得ず brings into 存在 a corresponding 行為／法令／行動する of 増加するd 投資. Nor is there any 構成要素 difference, 関連した in this 状況, between my schedule of the ごくわずかの efficiency of 資本／首都 or 投資 需要・要求する-schedule and the 需要・要求する curve for 資本／首都 熟視する／熟考するd by some of the classical writers who have been 引用するd above. When we come to the propensity to 消費する and its corollary the propensity to save, we are nearer to a difference of opinion, 借りがあるing to the 強調 which they have placed on the 影響（力） of the 率 of 利益／興味 on the propensity to save. But they would, 推定では, not wish to 否定する that the level of income also has an important 影響（力） on the 量 saved; whilst I, for my part, would not 否定する that the 率 of 利益／興味 may perhaps have an 影響（力） (though perhaps not of the 肉親，親類d which they suppose) on the 量 saved out of a given income. All these points of 協定 can be summed up in a proposition which the classical school would 受託する and I should not 論争; すなわち, that, if the level of income is assumed to be given, we can infer that the 現在の 率 of 利益／興味 must 嘘（をつく） at the point where the 需要・要求する curve for 資本／首都 corresponding to different 率s of 利益／興味 削減（する）s the curve of the 量s saved out of the given income corresponding to different 率s of 利益／興味.
But this is the point at which 限定された error creeps into the classical theory. If the classical school 単に inferred from the above proposition that, given the 需要・要求する curve for 資本／首都 and the 影響（力） of changes in the 率 of 利益／興味 on the 準備完了 to save out of given incomes, the level of income and the 率 of 利益／興味 must be uniquely correlated, there would be nothing to quarrel with. Moreover, this proposition would lead 自然に to another proposition which 具体的に表現するs an important truth; すなわち, that, if the 率 of 利益／興味 is given 同様に as the 需要・要求する curve for 資本／首都 and the 影響（力） of the 率 of 利益／興味 on the 準備完了 to save out of given levels of income, the level of income must be the factor which brings the 量 saved to equality with the 量 投資するd. But, in fact, the classical theory not 単に neglects the 影響（力） of changes in the level of income, but 伴う／関わるs formal error.
For the classical theory, as can be seen from the above quotations, assumes that it can then proceed to consider the 影響 on the 率 of 利益／興味 of (e.g.) a 転換 in the 需要・要求する curve for 資本／首都, without abating or 修正するing its 仮定／引き受けること as to the 量 of the given income out of which the 貯金 are to be made. The 独立した・無所属 variables of the classical theory of the 率 of 利益／興味 are the 需要・要求する curve for 資本／首都 and the 影響（力） of the 率 of 利益／興味 on the 量 saved out of a given income; and when (e.g.) the 需要・要求する curve for 資本／首都 転換s, the new 率 of 利益／興味, によれば this theory, is given by the point of 交差点 between the new 需要・要求する curve for 資本／首都 and the curve relating the 率 of 利益／興味 to the 量s which will be saved out of the given income. The classical theory of the 率 of 利益／興味 seems to suppose that, if the 需要・要求する curve for 資本／首都 転換s or if the curve relating the 率 of 利益／興味 to the 量s saved out of a given income 転換s or if both these curves 転換, the new 率 of 利益／興味 will be given by the point of 交差点 of the new positions of the two curves. But this is a nonsense theory. For the 仮定／引き受けること that income is constant is inconsistent with the 仮定／引き受けること that these two curves can 転換 独立して of one another. If either of them 転換, then, in general, income will change; with the result that the whole schematism based on the 仮定／引き受けること of a given income breaks 負かす／撃墜する. The position could only be saved by some 複雑にするd 仮定／引き受けること 供給するing for an (a)自動的な／(n)自動拳銃 change in the 行う-部隊 of an 量 just 十分な in its 影響 on liquidity-preference to 設立する a 率 of 利益／興味 which would just 相殺する the supposed 転換, so as to leave 生産（高） at the same level as before. In fact, there is no hint to be 設立する in the above writers as to the necessity for any such 仮定／引き受けること; 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 持つ／拘留する 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 可能性 of the level of income 存在 現実に a 機能（する）／行事 of the 率 of the 投資.
The above can be illustrated by a diagram as follows:
In this diagram the 量 of 投資 (or saving) I is 手段d vertically, and the 率 of 利益／興味 r horizontally. X1X1' is the first position of the 投資 需要・要求する-schedule, and X2X2' is a second position of this curve. The curve Y1 relates the 量s saved out of an income Y1 to さまざまな levels of the 率 of 利益／興味, the curves Y2, Y3, etc., 存在 the corresponding curves for levels of income Y2, Y3, etc. Let us suppose that the curve Y1 is the Y-curve 一貫した with an 投資 需要・要求する-schedule X1X1' and a 率 of 利益／興味 r1. Now if the 投資 需要・要求する-schedule 転換s from X1X1' to X2X2', income will, in general, 転換 also. But the above diagram does not 含む／封じ込める 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 投資 需要・要求する-schedule will 削減（する） it. If, however, we introduce the 明言する／公表する of liquidity-preference and the 量 of money and these between them tell us that the 率 of 利益／興味 is r2, then the whole position becomes determinate. For the Y-curve which intersects X2X2' at the point vertically above r2, すなわち, the curve Y2, will be the appropriate curve. Thus the X-curve and the Y-curves tell us nothing about the 率 of 利益／興味. They only tell us what income will be, if from some other source we can say what the 率 of 利益／興味 is. If nothing has happened to the 明言する／公表する of liquidity-preference and the 量 of money, so that the 率 of 利益／興味 is 不変の, then the curve Y2' which intersects the new 投資 需要・要求する-schedule vertically below the point where the curve Y1 intersected the old 投資 需要・要求する-schedule will be the appropriate Y-curve, and Y2' will be the new level of income.
Thus the 機能（する）／行事s used by the classical theory, すなわち, the 返答 of 投資 and the 返答 of the 量 saved out of a given income to change in the 率 of 利益／興味, do not furnish 構成要素 for a theory of the 率 of 利益／興味; but they could be used to tell us what the level of income will be, given (from some other source) the 率 of 利益／興味; and, alternatively, what the 率 of 利益／興味 will have to be, if the level of income is to be 持続するd at a given 人物／姿／数字 (e.g. the level corresponding to 十分な 雇用).
The mistake 起こる／始まるs from regarding 利益／興味 as the reward for waiting as such, instead of as the reward for not-hoarding; just as the 率s of return on 貸付金s or 投資s 伴う／関わるing different degrees of 危険, are やめる 適切に regarded as the reward, not of waiting as such, but of running the 危険. There is, in truth, no sharp line between these and the いわゆる 'pure' 率 of 利益／興味, all of them 存在 the reward for running the 危険 of 不確定 of one 肉親，親類d or another. Only ln the event of money 存在 used 単独で for 処理／取引s and never as a 蓄える／店 of value, would a different theory become appropriate.
There are, however, two familiar points which might, perhaps, have 警告するd the classical school that something was wrong. In the first place, it has been agreed, at any 率 since the 出版（物） of Professor Cassel's Nature and Necessity of 利益／興味, that it is not 確かな that the sum saved out of a given income やむを得ず 増加するs when the 率 of 利益／興味 is 増加するd; 反して no one 疑問s that the 投資 需要・要求する-schedule 落ちるs with a rising 率 of 利益／興味. But if the Y-curves and the X-curves both 落ちる as the 率 of 利益／興味 rises, there is no 保証（人） that a given Y-curve will intersect a given X-curve anywhere at all. This 示唆するs that it cannot be the Y-curve and the X-curve alone which 決定する the 率 of 利益／興味.
In the second place, it has been usual to suppose that an 増加する in the 量 of money has a 傾向 to 減ずる the 率 of 利益／興味, at any 率 in the first instance and in the short period. Yet no 推論する／理由 has been given why a change in the 量 of money should 影響する／感情 either the 投資 需要・要求する-schedule or the 準備完了 to save out of a given income. Thus the classical school have had やめる a different theory of the 率 of 利益／興味 in 容積／容量 I 取引，協定ing with the theory of value from what they have had in 容積／容量 II 取引，協定ing with the theory of money. They have seemed undisturbed by the 衝突 and have made no 試みる／企てる, so far as I know, to build a 橋（渡しをする） between the two theories. The classical school proper, that is to say; since it is the 試みる／企てる to build a 橋（渡しをする） 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 供給（する） to 会合，会う the 投資 需要・要求する-schedule; すなわち, 貯金 proper, which are the 貯金 dealt with by the classical school, 加える the sum made 利用できる by any 増加する in the 量 of money (this 存在 balanced by some 種類 of 徴収する on the public, called '軍隊d saving' or the like). This leads on to the idea that there is a 'natural' or '中立の' or equilibrium' 率 of 利益／興味, すなわち, that 率 of 利益／興味 which equates 投資 to classical 貯金 proper without any 新規加入 from '軍隊d 貯金'; and finally to what, assuming they are on the 権利 跡をつける at the start, is the most obvious 解答 of all, すなわち, that, if the 量 of money could only be kept constant in all circumstances, 非，不，無 of these 複雑化s would arise, since the evils supposed to result from the supposed 超過 of 投資 over 貯金 proper would 中止する to be possible. But at this point we are in 深い water. 'The wild duck has dived 負かす／撃墜する to the 底（に届く）¾as 深い as she can get¾and bitten 急速な／放蕩な 持つ／拘留する of the 少しのd and 絡まる and all the rubbish that is 負かす／撃墜する there, and it would need an extraordinarily clever dog to dive after and fish her up again.'
Thus the 伝統的な 分析 is 欠陥のある because it has failed to 孤立する 正確に the 独立した・無所属 variables of the system. Saving and 投資 are the determinates of the system, not the determinants. They are the twin results of the system's determinants, すなわち, the propensity to 消費する, the schedule of the ごくわずかの efficiency of 資本／首都 and the 率 of 利益／興味. These determinants are, indeed, themselves コンビナート／複合体 and each is 有能な of 存在 影響する／感情d by 見込みのある changes in the others. But they remain 独立した・無所属 in the sense that their values cannot be inferred from one another. The 伝統的な 分析 has been aware that saving depends on income but it has overlooked the fact that income depends on 投資, in such fashion that, when 投資 changes, income must やむを得ず change in just that degree which is necessary to make the change in saving equal to the change in 投資.
Nor are those theories more successful which 試みる／企てる to make the 率 of 利益／興味 depend on 'the ごくわずかの efficiency of 資本／首都'. It is true that in equilibrium the 率 of 利益／興味 will be equal to the ごくわずかの efficiency of 資本／首都, since it will be profitable to 増加する (or 減少（する）) the 現在の 規模 of 投資 until the point of equality has been reached. But to make this into a theory of the 率 of 利益／興味 or to derive the 率 of 利益／興味 from it 伴う／関わるs a circular argument, as Marshall discovered after he had got half-way into giving an account of the 率 of 利益／興味 along these lines. For the 'ごくわずかの efficiency of 資本／首都' partly depends on the 規模 of 現在の 投資, and we must already know the 率 of 利益／興味 before we can calculate what this 規模 will be. The 重要な 結論 is that the 生産（高） of new 投資 will be 押し進めるd to the point at which the ごくわずかの efficiency of 資本／首都 becomes equal to the 率 of 利益／興味; and what the schedule of the ごくわずかの efficiency of 資本／首都 tells us, is, not what the 率 of 利益／興味 is, but the point to which the 生産（高） of new 投資 will be 押し進めるd, given the 率 of 利益／興味.
The reader will readily 高く評価する／（相場などが）上がる that the problem here under discussion is a 事柄 of the most 根底となる theoretical significance and of 圧倒的な practical importance. For the 経済的な 原則, on which the practical advice of 経済学者s has been almost invariably based, has assumed, in 影響, that, cet. par., a 減少（する） in spending will tend to lower the 率 of 利益／興味 and an 増加する in 投資 to raise it. But if what these two 量s 決定する is, not the 率 of 利益／興味, but the aggregate 容積／容量 of 雇用, then our 見通し on the 機械装置 of the 経済的な system will be profoundly changed. A 減少（する）d 準備完了 to spend will be looked on in やめる a different light If, instead of 存在 regarded as a factor which will, cet. par., 増加する 投資, it is seen as a factor which will, cet. par., 減らす 雇用.