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...

High-skilled immigrants are a very important component of U.S. innovation and entrepreneurship. Immigrants account for roughly a quarter of U.S. workers in these fields, and they have a similar contribution in terms of output measures like patents or firm starts. This contribution has been...

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...

Firms play a central role in the selection, sponsorship, and employment of skilled immigrants entering the United States for work through programs like the H-1B visa. This role has not been widely recognized in the literature, and the data to better understand it have only recently become...