Ludwig Hamburger (1890–1968): From Relaxation Oscillations to Business Cycles

Abstract Several authors have been interested in Ludwig Hamburger’s attempt to analyse business cycles with a nonlinear endogenous model in the early 1930s. Indeed, Hamburger was one of the first, if not the first, to suggest applying Van der Pol’s relaxation oscillations to business cycles. Ragnar Frisch was interested in his work when he was working on his 1933 seminal paper on a propagation-impulse model, in which we find some references to this suggestion. Despite the interest in Hamburger’s work, the breadth, scope and impact of his works remain unknown and misunderstood, for both historians of economics and sciences. Moreover, several errors, such as the reason why Hamburger did not continue his original work in economics, exist in the economic literature concerning this author and the diffusion of his work in economics. The present work provides a biography of Ludwig Hamburger and corrects the errors we find in the literature. It also sheds new light on the origins of his attempt to analyse business cycles with a nonlinear endogenous model.