The Effect Of Immigration On Productivity: Evidence From U.S. States
利用1960年前美国各州移民社区的存在和距墨西哥边境的距离作为工具变量，研究发现移民并未挤占就业，反而与全要素生产率正相关，并降低了生产技术的高技能偏向。
In this paper we analyze the long-run impact of immigration on employment, productivity, and its skill bias. We use the existence of immigrant communities across U.S. states before 1960 and the distance from the Mexican border as instruments for immigration flows. We find no evidence that immigrants crowded out employment. At the same time, we find that immigration had a strong, positive association with total factor productivity and a negative association with the high skill bias of production technologies. The results are consistent with the idea that immigrants promoted efficient task specialization, thus increasing TFP, and also promoted the adoption of unskilled-efficient technologies. © 2011 The President and Fellows of Harvard College and the Massachusetts Institute of Technology.