The Nature and Role of Equilibrium in Keynes’s General Theory

Although Keynes believed that his book, The General Theory of Employment, Interest and Money would ‘largely revolutionise — not, I suppose, at once but in the course of the next ten years — the way the world thinks about economic problems’ (Keynes, 1973a, p. 492), most of the analytical methods that he used were hardly new. His mentor in this regard was Alfred Marshall, and The General Theory can be viewed as utilising Marshallian analysis to demonstrate that a modern capitalist economy can get stuck in a situation of less than full employment. Keynes concentrated on short-period situations, and made selective use of equilibrium in the two senses of that term — equilibrium as a position of ‘rest’,1 and equilibrium as a ‘chosen’ position.2 It was the level of employment that was in equilibrium according to the former definition in that there was no tendency for it to change given the values of the parameters. Consumption and investment expenditures, and the outputs of firms with their predetermined productive capacity, were in equilibrium according to the latter definition. Their values were those which were preferable to the possible alternative values in the particular short-period.