Marx and Kalecki on aggregate instability and class struggle.

Summary Michal Kalecki developed his original model of the business cycle in the early 1930s. Several versions referred as versions I, II and III have been developed until the late 1960s from which Kalecki draw three central propositions on instability and class struggle: (1) the capitalist system “cannot break the impasse of fluctuations around a static position” unless it is shocked by “semi-exogenous factors”, (2) the dynamics of the profit rate and investment – as in version I and II – may be disconnected from “class struggle” and (3) when class struggle impacts the dynamics of the economy – as in version III – this is happening in a context in which expected profitability of new investment projects is negatively related to the profit share. In this article, we want to show that each of these three proposals represents key differences with Marx.