Like an Ink Blot on Paper: Testing the Diffusion Hypothesis of Mass Migration, Italy 1876-1920

Abstract:

Despite greater incentives for migration due to lower real wages, countries in southern and eastern Europe, such as Italy, were latecomers to the Age of Mass Migration relative to wealthier western countries such as Germany and Britain---a phenomenon called the delayed migration puzzle. We test the diffusion hypothesis, which argues that mass migration from the poorer countries was delayed until it was triggered by exposure to geographically expanding networks of individuals with social links to previous migrants. Focusing on post-unification Italy, we construct a comprehensive annual commune-level panel of emigration over four decades. We develop a new set of stylized facts on the Italian emigration that are consistent with the four main predictions of the diffusion hypothesis. Most importantly, we find that Italian mass migration to North America began in a few separate ``epicenters'' and expanded from there in an orderly pattern of spatial expansion over time. We then show that this pattern was the product of a mechanism in which a commune's emigration rate was affected by emigration from its neighbors---the fundamental building block of the diffusion hypothesis. These findings contribute to an important revision to the economic history of the Age of  Mass Migration and advance the literature on the causes of mass migration more generally.