Mass Migration and Technological Change

This paper studies the effect of emigration on technological change in sending lo- cations after one of the largest migration events in human history, the mass migration from Europe to the United States in the 19^th century. To establish causality, we adopt an instrumental variable strategy that combines local growing-season frost shocks with proximity to emigration ports. Using detailed data on patents, we find that emigration led to an increase in innovative activity in sending localities. Using data on capital and labor inputs in agriculture and industry, we find evidence of an increased capital intensity related to new technologies in both sectors. We argue that these results are consistent with theories of induced (labor-saving) innovation due to high labor costs following emigration.