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...

We estimate the aggregate long-run elasticity of substitution between more educated workers and less educated workers (the slope of the inverse demand curve for more relative to less educated workers) at the U.S. state level. Our data come from the (five) 1950-1990 decennial censuses. Our...

The literature on schooling externalities in U.S. cities and states is rather mixed: positive external effects of average education levels are hardly found while positive externalities from the share of college graduates are more often identified. We propose a simple model to reconcile this...

Knowledge flows within and across countries may have important consequences for both productivity and innovation. We use data on 1.5 million patents and 4.5 million citations to estimate knowledge flows at the frontier of technology across 147 subnational regions during 1975-1996 within the...