Théories réelles versus monétaires des cycles d'équilibre

After dominance of growth theory for more than two decades, business-cycle theory entered centre stage again in the 1970s. Different attempts, by various authors, have tried to connect these modern contributions to the interwar debates: from Lucas (1977), quoting Hayek on the challenge to incorporate cyclical phenomena into the system of economic equilibrium theory, to Plosser (1989) defending a purely real approach to business cycles from a methological point of view. Plosser also referred to Hicks's position in his controversy with Hayek on the fundamental nature of fluctuations. Despite the success of the modern literature in providing an Equilibrium Business Cycle theory, at first sight it seems that the same (old) debate confronting real versus monetary approaches is still there. A closer inspection shows that the modern tools deeply affected the nature of the arguments. The purpose of this paper is to examine the differences between the interwar and the modern debates on how economic theory deals with fluctuations.