On the concepts of period and run in economic theory *

Heinz Kurz has made major contributions to our understanding of long-period production‘interdependent models inspired by Piero Sraffa's classic writings (see, for example, Kurz and Salvadori, 1995). In doing so he has, on the whole, sided with the view of Pierangelo Garegnani, John Eatwell and Murray Milgate (see, for example, Eatwell, 1997) that, traditionally and necessarily, rigorous economic theory can only be long-period in the sense of analysing relationships between dominant, persistent forces at work in the economy. This implies that there is no place, or at least little fundamental place, for a theory of the short period in its own right: this is so, despite Richard Kahn's superb, path-breaking 1929 Fellowship Dissertation for King's College, Cambridge, ‘The economics of the short period’, ¹ and the dominant view of Keynes scholars that the analysis of The General Theory itself is mainly placed in a short-period setting, as it is in Michal Kalecki's approach in his analysis of accumulation, the cycle and growth. The last occurred in Keynes's own as well as others’ contributions, not least because of Kahn's key influence on the development of Keynes's thought as he moved from A Treatise on Money (1930) to The General Theory (1936) (see Harcourt, 1994, 1995, Ch. 5).