Kondratieff, Schumpeter, and Kuznets: Trend Periods Revisited

The analysis of fluctuations longer than the nine-year business cycle has been somewhat confused by a failure to distinguish sharply and to relate three distinct phenomena: the forces set in motion by a leading sector in growth, stemming from the introduction and progressive diffusion of a new technology, and its deceleration; the forces set in motion by changes in the profitability of producing foodstuffs and raw materials, whether from the side of prices or technology, including their effects on investment in new territories and mines, on capital movements, interest rates, terms of trade, and domestic and international income distribution; and the forces set in motion (notably, in housing and urban infrastructure) by large waves of international or domestic migration or other forces changing the rate of family formation, housing demand, and the size of the working force. As the world economy unfolded after 1783, these three phenomena operated concurrently and related to each other in complex ways not easy to disentangle. Nevertheless, the substantial literature on long waves can be usefully clarified by distinguishing these phenomena more sharply than is sometimes done and then relating them to each other at particular times and places. The exercise of doing so has, I believe, some general implications for economic theory, for they are all aspects of the process of adjustment towards a moving equilibrium, never attained—a process for which we lack an adequate dynamic theory.