Migrants and the Making of America:The Short- and Long-Run Effects of Immigration during the Age of Mass Migration* Nathan Nunn† Nancy Qian‡ Sandra Sequeira§ January 2017 Abstract: We study European immigration into the United States during the Age of Mass Migration (1850–1920), and estimate its long-term effects on economic prosperity. We exploit variation in the extent of immigration across counties arising from the interaction of fluctuations in aggregate immigrant inflows and the gradual expansion of the railway. We find that locations with more historical immigration today have higher incomes, less poverty, less unemployment, higher rates of urbanization, and greater educational attainment. The long-run effects appear to arise from the persistence of sizeable short-run benefits, including earlier and more intensive industrialization, increased agricultural productivity, and more innovation. Keywords: Immigration, historical persistence, economic development. JEL Classification: B52;F22;N72;O10;O40. *We thank Paulo Costa, Daria Kutzenova, Eva Ng, Matthew Summers, Guo Xu, and Adam Xu for excellent research assistance. We are grateful for comments received from Ran Abramitzky, Philipp Ager, Leah Boustan, Melissa Dell, Dave Donaldson, Claudia Goldin, Casper Worm Hansen, Jeff Frieden, Larry Katz, Petra Moser, and Gavin Wright, as well as audiences at numerous seminars and conferences. †Harvard University, NBER and BREAD. (email:
[email protected]) ‡Yale University, NBER and BREAD. (email:
[email protected]) §London School of Economics. (email:
[email protected]) 1. Introduction An important issue within current American political discourse is the impact that immigrants have on the communities into which they settle. While this topic has received significant attention to date, the focus has tended to be on the short-term effects of immigrants.1 However, also important is the question of what long-run impacts immigrants have in the locations into which they settle, particularly since the short- and long-term impacts may be very different.