star scientists and firms have a large positive impact on firms'" research productivity, increasing the average firm … there is little evidence of geographically localized knowledge spillovers. In early industry" formation, star scientists … firm scientists work" in the stars' university laboratories in contrast to America where the stars are more likely to work …

depend upon immigrant scientists and engineers. Spatial adjustments are faster for technologies that depend heavily on …

detailed data on inventors contained in patents, and harness it for economic research. Patent data has long been used in … "John Smith" problem). Given that there are over 2 million patents with 2 inventors per patent on average, the "who is who …-inventors, etc. Forty percent of them have more than one patent, and 70,000 have more than 10 patents. We can trace those multiple …

The recruitment of foreign scientists enhances US science through an expanded workforce but could also cause harm by … displacing better connected domestic scientists, thereby reducing localized knowledge spillovers. We develop a model in which a … sufficient condition for the absence of overall harm is that immigrant scientists generate at least the same level of localized …