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...

The growing peer effects literature pays particular attention to the role of stars. We decompose the causal effect of hiring a star in terms of the productivity impact on: 1) co-located incumbents and 2) new recruits. Using longitudinal university department-level data we report that hiring a...

When firms recruit inventors, they acquire not only the use of their skills but also enhanced access to their stock of ideas. But do hiring firms actually increase their use of the new recruits' prior inventions? Our estimates suggest they do, quite significantly in fact, by approximately 202%...

We report a puzzling pair of facts concerning the organization of science. The concentration of research output is declining at the department level but increasing at the individual level. For example, in evolutionary biology, over the period 1980 to 2000, the fraction of citation-weighted...