¹ Cf. James Bonar, Philosophy and Political Economy, London, 1893, pp. 356–357.

² Paul M. Sweezy, The Theory of Capitalist Development, New York, 1942, p. 68.

³ A. L. Bowley, Wages and Income in the United Kingdom Since 1860, Cambridge, 1937, p. xvi. Statistical data likewise indicate an approximate constancy in the proportion of wages and salaries to the total American national income, with the exception of a pronounced rise in the former's favor during the worst years of the depression. Cf., Simon Kuznets, National Income and Its Composition, 1919–1938, New York, 1941, Vol. I, p. 217.

⁴ Simon Kuznets, National Income: A Summary of Findings, New York, 1946, pp. 99–100. Also, cf. Lawrence R. Klein, Theories of Effective Demand and Employment, The Journal of Political Economy, Vol. LV, (1947), p. 121.

⁵ Karl Marx, Capital, Vol. III, (Untermann translation), Chicago, 1909, p. 304.

⁶ Ibid., p. 294.

⁷ John Maynard Keynes, The General Theory of Employment, Interest, and Money, New York, 1936, p. 136.

⁸ “To what extent the two parties divide the profit, in which they both share, is in itself as much a purely empirical fact belonging to the realm of accident as the division of the shares of common profit of some corporate business among different shareholders by percentage.” Karl Marx, Capital, Vol. III, p. 428.

⁹ It is “only the separation of capitalists into money—capitalists and industrial capitalists, which transforms a portion of the profit into interest, which creates the category of interest at all.” Ibid., Vol. III, p. 435. A sociological element, moreover, enters into the determination of the rate of surplus-value itself. The value of labor-power is only the lower limit to which wages can be driven. The distribution otherwise between wages and surplus-value “depends on the relative weight, which the pressure of capital on the one side, and the resistance of the labourer on the other, throws into the scale.” Vol. I., p. 572–573.

¹⁰ Keynes, loc. cit., p. 246. Marx, op. cit., p. 428.

¹¹ A. C. Pigou, The Economics of Welfare, Second Edition, London, 1924, p. 632.

¹² Savings, Investment, and National Income, Monograph No. 37, Temporary National Economic Committee, Washington, D.C., 1941, p. 99.

¹³ For the details of this paragraph, cf., Spurgeon Bell, Productivity, Wages, and National Income, Brookings Institution, Washington, D.C., 1940, pp. 297, 287, 271–273.

¹⁴ David Weintraub, Effects of Current and Prospective Technological Developments upon Capital Formation, The American Economic Review, Vol. XXIX, (1939), Pt. 2, Supplement, p. 15.

¹⁵ Alvin H. Hansen, Full Recovery or Stagnation? New York, 1938, pp. 314–315. Also, cf., Hansen's judgment that for the economy as a whole, “there is no good evidence that the advance of technique has resulted in recent decades, certainly not in any significant measure, in any deepening of capital. … Though the deepening process is all the while going on in certain areas, elsewhere capital-saving inventions are reducing the ratio of capital to output.” Econonomic Progress and Declining Population Growth, The American Economic Review, Vol. XXIX, (1939), p. 7.

¹⁶ Karl Marx, A Contribution to the Critique of Political Economy, Preface, in Selected Works, New York, Vol. I, p. 356–357.

¹⁷ It is unwise therefore to attach too much significance to the decline in the rate of growth of some single industry in the capitalist economy. Varga, for instance, emphasizes that during the period from 1913 to 1930, “the rate of growth of railways has diminished considerably all over the capitalist world.” Cf., E. Varga and L. Mendelsohn, New Data for V. I. Lenin's Imperialism, New York, 1940, p. 211. This same period, however, saw the tremendous expansion of the automobile industry. Any judgment as to the decline of the capitalist system is limited by the indeterminacy of the factors which control the net rate of capital formation.

¹⁸ Karl Marx, Capital, Vol. I, pp. 444–445.

¹⁹ Alvin H. Hansen, Economic Progress and Declining Population Growth, The American Economic Review, Vol. XXIX (1939), p. 10.

²⁰ George Terborgh, The Bogey of Economic Maturity, Chicago, 1945, p. 92.

²¹ Alvin H. Hansen, Some Notes on Terborghs ‘The Bogey of Economic Maturity,‘ The Review of Economic Statistics, Vol. XXVIII, (1946), p. 15.

²² Terborgh, op. cit., pp. 93–94.

²³ Joseph A. Schumpeter, The Creative Response in Economic History, The Journal of Economic History, Vol. VII (1947). p. 150.

²⁴ David McCord Wright, ‘The Great Guessing Game’: Terborgh versus Hansen, The Review of Economic Statistics, Vol. XXVIII (1946), p. 19.

²⁵ As Joan Robinson has noted, Marx does not have a systematic theory as to the relation of investment to the workings of the economy. Cf., An Essay on Marxian Economics, London, 1942, p. 56. The limitation which the class distribution of income imposes on investment is implicit, however, in much of his analysis.

²⁶ J. M. Keynes, Some Economic Consequences of a Declining Population, The Eugenics Review, Vol. XXIX, (1937), p. 14, 17.

²⁷ After considering all the possible direct and indirect results of the introduction of the trackless trolley, Weir M. Brown justly concludes, … “who is prepared to say whether, for the economy as a whole, this is a ‘capital-saving’ or a labor-saving' change?”, ‘Labor-saving’ and ‘Capital-saving’ Innovations, The Southern Economic Journal, Vol. XIII, p. 111.

²⁸ William Fellner, The Technological Argument of the Stagnation Thesis, The Quarterly Journal of Economics, Vol. LV, (1941), p. 651.

²⁹ What the effects of capital-saving or labor-saving invention on the distribution of national income will be is likewise dependent upon the advent of new industries. Pigou has proposed the view that a capital-saving invention diminishes the ratio of labor to capital in industries other than the improved one because of the release of a quantity of surplus capital. He then argues that capital-saving invention tends therefore to lower the marginal productivity of capital relative to labor, and that consequently, the distribution of national income is altered in favor of labor. The whole argument however assumes an abundance of investment outlets which only new industries can provide. The industrial structure does not automatically absorb the surplus capital liberated by capital-saving invention.

³⁰ Karl Marx, Capital, Vol. II, p. 578.

³¹ The Correspondence of Karl Marx and Friedrich Engels, transl. by Dona Torr, London, 1936, p. 386.