Study of long waves in the interwar period

Problems of economic cycle moves (including long run cycles) were studied thoroughly in the period between World Wars; Besides the U.S.S.R. (where this topic was analyzed beside N.D. Kondratieff also by L.D. Trotsky) the studies covering the: long-run economic "booms" were written also by scientists in Germany (for instance E. Wagemann), Belgium (L.H. Dupriez and others), France(E Simiand and others), Sweden (J.G.K. Wicksell, G.K. Casell) and by many Americans (W.C. Mitchell, A. Hansen or J.M. Clark). Despite all these Contributions (mostly trying to explain of mechanism of long-run waves on the base of exogenous factors) the basic progress in the modern theory of long waves is linked with N.D. Kondratieff and later with concept of accumulation of basic innovations developed by J.A. Schumpeter.