Theory of Economic Dynamics

In his Essays in the Theory of Business Cycle published in Polish in
1933, Kalecki clearly stated the principle of effective demand in
mathematical form. By 1935 he outlined his theory of employment,
demolished the then-orthodox remedy for a depression-that is, wage
cutting-and pinpointed the importance of investment for economic
dynamics. Thus, although his training had been in Marxist economics, he
succeeded in anticipating the Keynesian system, and, as Joan Robinson
has pointed out, his claim to priority of publication is indisputable
although he never mentioned this fact.