Immigrants and the Making of America
研究1850-1920年欧洲移民对美国经济繁荣的长期影响，发现移民多的县如今收入更高、贫困和失业率更低、城市化和教育水平更高，短期收益如工业化、农业生产力提升和创新具有持久性。
Abstract We study the effects of European immigration to the U.S. during the Age of Mass Migration (1850–1920) on economic prosperity. Exploiting cross-county variation in immigration that arises from the interaction of fluctuations in aggregate immigrant flows and of the gradual expansion of the railway network, we find that counties with more historical immigration have higher income, less poverty, less unemployment, higher rates of urbanization, and greater educational attainment today. The long-run effects seem to capture the persistence of short-run benefits, including greater industrialization, increased agricultural productivity, and more innovation.