This paper studies the impact of U.S. immigration barriers on global knowledge production. We present four key findings. First, among Nobel Prize winners and Fields Medalists, migrants to the U.S. play a central role in the global knowledge network—representing 20-33% of the frontier knowledge...

Scientists typically self-organize into teams, matching with others to collaborate in the production of new knowledge. We present the results of a field experiment conducted at Harvard Medical School to understand the extent to which search costs affect matching among scientific collaborators....

To examine the drivers of innovation, this paper studies the global R&D effort to fight the deadliest diseases and presents four results. We find: (1) global pharmaceutical R&D activity—measured by clinical trials—typically follows the 'law of diminishing efforts': i.e. the elasticity of R&D...

This paper studies the impact of U.S. immigration barriers on global knowledge production. We present four key findings. First, among Nobel Prize winners and Fields Medalists, migrants to the U.S. play a central role in the global knowledge network— representing 20-33% of the frontier...

Immigration is rapidly changing the composition of the R&D workforce in the United States. We study here Chinese chemists and chemical engineers who migrate to the United States for their graduate studies. We analyze productivity at the individual researcher level, thus bypassing the...

We study migration in the right tail of the talent distribution using a novel dataset of Indian high school students taking the Joint Entrance Exam (JEE), a college entrance exam used for admission to the prestigious Indian Institutes of Technology (IIT). We find a high incidence of migration...