The last century economists have dared to predict, if not the end of the business cycle, at least the progress towards economic stability. This was because of the stabilization policies and structural changes of the postwar economy that seemed to support the reduction of economic fluctuations, at least in the short term. Indeed, postwar expansions have been longer than those before World War I, indicating that recessions have occurred less frequently than in the past. What caused this evolution and what are the characteristics of business cycles since the Second World War are questions that we try to find answers in this paper.