[몇몇 자료] Keynes and Paul Samuelson

자료 1: The Comings of Keynsianism to America: Conversations with the Founders of Keynsian Economics (David C. Conlander and Harry Landreth Ed., 1996)

자료 2: 

 2.1. John Maynard Keynes, 2nd ed. ( Paul Davidson, 2009 [2007] )

 2.2. Interpreting Keynes for the 21st century ( Paul Davidson, 2007 )

자료 3: Mr. Keynes and the Moderns, PDF ( Paul Krugman, 21 June 2011)

자료 4 : Samuelson And The Keynes/Post Keynesian Revolution: The Evidence... ( Paul Davidson )

(... ... ) Samuelson has indicated that his first knowledge of Keynes’s General Theory was gained from Bryce [C–L, 1996, p. 158]. Moreover, even after reading the General Theory in 1936, Samuelson, perhaps reflecting Bryce’s view of the difficulty of understanding Keynes’s book, found the General Theory analysis “unpalatable” and not comprehensible [C-L, 1996, p. 159]. Samuelson finally indicated that “The way I finally convinced myself was to just stop worrying about it [about understanding Keynes’s analysis] . I asked myself: why do I refuse a paradigm that enables me to understand the Roosevelt upturn from 1933 till 1937? ... I was content to assume that there was enough rigidity in relative prices and wages to make the Keynesian alternative to Walras operative” [C-L, 1996, pp159-160].

Keynes’s biographer, Lord Skidelsky [1992, p. 512] recognized the problem with this Samuelson interpretation of Keynes when he wrote “ the validity of Keynes’s ‘general theory’ rests on his assertion that the classical theory... is, as he put it in his lectures, “nonsense’. If it [Walrasian classical theory] were true, the classical ‘special case’ would, in fact, be the “general theory’[ii] and Keynes’s aggregative analysis not formally wrong, but empty, redundant. It is worth noting, at this point, that mainstream economists after the Second World War treated Keynes’s theory as a ‘special case’ of the classical [Walrasian] theory, applicable to conditions where money wages and interest were ‘sticky’. Thus his theory was robbed of its theoretical bite”iii.

Apparently Samuelson never tried to comprehend Keynes’s analytical foundation and framework. For in 1986 Samuelson was still claiming that “we [Keynesians] always assumed that the Keynesian underemployment equilibrium floated on a substructure of administered prices and imperfect competition” [C-L, 1996, p.160]. When pushed by Colander and Landreth as to whether this requirement of rigidity was ever formalized in his work, Samuelson’s response was “There was no need to” [C-L, 1996, p. 161].

Yet specifically in chapter 19 of The General Theory and even more directly in his published response to Dunlop and Tarshis, Keynes [1939b] had already responded in the negative to this question of whether his analysis of underemployment equilibrium required imperfect competition, administered prices, and/or rigid wages. Dunlop and Tarshis had argued that the purely competitive model (i.e., the Walrasian model) was not empirically justified, therefore it was monopolistic price and wage fixities that was the basis of Keynes’s unemployment equilibrium. Keynes reply was simply :”I complain a little that I in particular should be criticised for conceding a little to the other view” [ Keynes, 1973b, p. 411]. In chapters 17 -19 of his General Theory,

Keynes explicitly demonstrated that even if perfectly flexible money wages and prices existed (“conceding a little to the other side”), there was no automatic mechanism that could restore the full employment level of effective demand . In other words, Keynes’s general theory could show that, as a matter of logic, less than full employment equilibrium could exist in a purely competitive economy with freely flexible wages and prices.

Obviously Samuelson, who became the premier American Keynesian of his time, had either not read, or not comprehended, (1) Keynes’s response to Dunlop and Tarshis or even (2) chapter 19 The General Theory which was entitled “Changes in Money Wages”. In chapter 19 Keynes explicitly indicates that the theory of unemployment equilibrium did not require “a rigidity” in money wages [Keynes, 1936a, p. 257]. As Keynes put it:

“For the classical theory has been so accustomed to rest the supposedly self-adjusting character of the economic system on the assumed fluidity of money wages; and, when there is rigidity, to lay on this rigidity the blame of maladjustment..... My difference from this theory is primarily a difference of analysis” [Keynes, 1936a, p. 257].

Keynes [1936a, p. 259, first emphasis added] indicated that to assume that rigidity was the sole cause of the existence of an unemployment equilibrium lay in accepting the argument that the micro-demand functions “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 aggregate effective demand. It is invalid, therefore to transfer the argument to industry as a whole unless we also transfer the argument that the aggregate effective demand is fixed. Yet, this assumption reduces the argument to an ignoratio elenchi.”

(... ...) 

In contrast, on the very first text page of The General Theory, Keynes [1936a, p. 3] explained “that the “postulates of the classical [Walrasian] theory are applicable to a special case only and not to the general case.... Moreover the characteristics of the special case assumed by the classical theory happen not to be those of the economics society in 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”.

In the preface to the German language edition of The General Theory [1936b, p. ix] Keynes specifically noted ”This is one of the reasons which justify my calling my theory a general [emphasis in the original] theory. Since it is based on fewer restrictive assumptions [‘weniger enge Voraussetzunger stutz’] than the orthodox theory, it is also more easily adopted to a large area of different circumstances” [ Second emphasis added]. In other words, Keynes argued that what made his analytical system more general than the classical (or more recent Walrasian general equilibrium) analysis is that Keynes’s general theory requires a smaller common axiomatic base (fewer restrictive axioms) than any other alternative theory. (... ...)