Immigrants account for about a quarter of US invention and entrepreneurship despite a policy environment that is not well suited for these purposes. This chapter reviews the U.S. immigration policy environment that governs how skilled migrants move to America for employment-based purposes. We...

Tech clusters like Silicon Valley play a central role for modern innovation, business competitiveness, and economic performance. This paper reviews what constitutes a tech cluster, how they function internally, and the degree to which policy makers can purposefully foster them. We describe the...

We investigate the speed at which clusters of invention for a technology migrate spatially following breakthrough inventions. We identify breakthrough inventions as the top one percent of US inventions for a technology during 1975-1984 in terms of subsequent citations. Patenting growth is...