Relaxation oscillations in the early development of econometrics: coming (almost) full circle (1929-1951)

In 1930, Ludwig Hamburger published in Dutch an article on the possibility to account for "economic instability" by using relaxation oscillations, a model of nonlinear vibrations which had recently been developed by the physicist Balthazar van der Pol. Hamburger's article, translated in French in 1931, attracted a strong interest in the nascent Econometric Society and in particular from Ragnar Frisch and François Divisia, who decided to make it one of the theme of the first European meeting of the Econometric Society, scheduled in Lausanne in 1931. Although Hamburger did not provide an economic theory going beyond the analogy with van der Pol's equation, he did propose to integrate shocks in his models in a manner that was completely different from what came after him. His approach was however shunned by other economists because its potentialities were not understood for at least three reasons. It took two decades before Richard Goodwin, spurred by the same physicist that was present at the early meetings of the Econometric Society, finally managed to build a convincing economic model relying on nonlinear oscillations.