We investigate how knowledge similarity between two individuals is systematically related to the likelihood that a serendipitous encounter results in knowledge production. We conduct a natural field experiment at a medical research symposium, where we exogenously varied opportunities for...

We investigate whether having an advisor of the same gender is correlated with the productivity of PhD science students and their propensity to stay in academic science. Our analysis is based on an original dataset covering nearly 20,000 PhD graduates and their advisors from U.S. chemistry...

We investigate whether excessively optimistic beliefs play a role in the persistent demand for doctoral and postdoctoral training in science. We elicit the beliefs and career preferences of doctoral students through a novel survey and randomize the provision of structured information on the true...

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...

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...