The recent literature on externalities of schooling in the U.S. is rather mixed: positive external effects of average education are hardly found at all, while often positive externalities from the share of college graduates are identified. This paper proposes a simple model to explain this fact...

Many workers with low levels of educational attainment immigrated to the United States in recent decades. Large inflows of less educated immigrants would reduce wages paid to comparably-educated native-born workers if the two groups are perfectly substitutable in production. In a simple model...

The diffusion of knowledge in the world generates positive externalities if knowledge flows increase the productivity of R&D. Our work analyzes knowledge diffusion and knowledge externalities in generating innovation and in determining productivity. We first estimate the determinants of...