This study explores the importance of knowledge transfer for international technology diffusion by examining ethnic scientific and entrepreneurial communities in the US and their ties to their home countries. US ethnic research communities are quantified by applying an ethnic-name database to...

This study evaluates the impact of high-skilled immigrants on US technology formation. Specifically, we use reduced-form specifications that exploit large changes in the H-1B visa program. Fluctuations in H-1B admissions levels significantly influence the rate of Indian and Chinese patenting in...

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...