We test how a reduction in travel cost affects the rate and direction of scientific research. Using a fine-grained, scientist-level dataset within chemistry (1991-2012), we find that after Southwest Airlines enters a new route, scientific collaboration increases by 50%, an effect that is...

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...