Two Critics of Marginalist Theory: Piero Sraffa and John Maynard Keynes

The paper discusses the contributions of two major critics of marginalist theory: John Maynard Keynes and Piero Sraffa. While Keynes and his followers directed their attention and energy first and foremost to a criticism of Say's law, Sraffa and his followers did so with respect to marginal productivity theory. However, as the paper shows, Sraffa's criticism implies also a rejection of Say's law. The main focus of the paper is the route by means of which Sraffa arrived at his analysis and to what extent it is compatible with or contradicts Keynes's.