[Schumpeter's comment on] Fisher's marginal rate of return over cost

자료: 구글도서

※ 메모:

(... de)cision at the hands of Keynes. As everyvody knows, it represents current total national consumption(total expenditure on 'consumption' in terms of wage units) as a function of current national income (in wage units) and expresses the arbitrary postulate that any increase in the latter is always attended by an increase in the former but by a smaller one.[주13] The investment function is less easy to convey in a few words because of its connection with the very important dynamical considerations of Keynes's chapter 11 and 12, which do not enter into its explicit statement. It relates the rae of aggregate investment to the marginal efficiency of (physical) 'capital in general which that rate of investment will establish' (op. cit. p. 136), the marginal efficiency of capital being defined as the relation between the expected yield of one more unit (properly chosen) of any capital good and the cost of producing this unit.[주14]. This, as Keynes pointed out, is the same as Fisher's 'marginal rate of return over cost.'[주15] But there is this difference between the two : whereas with Fisher this marginal rate of return over costㅡwhich implies a discounting process of the series of expected yieldsㅡconstitutes the basic fact about the interest phenomenon, Keynes broke away at this point from what I have termed the Barbon tradition and, in intent at least, established a monetary theory of interest, according to which interest is not derived from, or expressive of, anything that has, in whatever form, to do with the net return from capital goods.[주16]

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[주15] ^Theory of Interest^(1930), p. 168. I can, however, testify to the fact that Keynes, whose knowledge of economic literature and particularly of contemporaneous and non-English literature was not of the first order, arrived at his concept quite independently and that he inserted the acknowledgment in question upon his attention's having been drawn to Fisher's formulation. When he received the information, Keynes possibly ackwowledged too much. Such, at least, is Professor Lerner's opinion. On the other hand, it may be argued that both concepts are indeed improvements upon the concept of marginal productivity of capital as developed by Marshall and especially Wicksellㅡand this again points back to Bohm-Bawerkㅡbut not more than that. The 'prospectiveness' of marginal productivity of capital and its relation to its replacement costs, few if any authors who used it would have denied.