This paper studies productivity and preferences in scientific research. Collaboration is increasingly important for innovation in science and other domains, but we have limited understanding of the factors researchers use to choose their collaborators and the projects they work on. Here, we use a model of strategic network formation and a recently developed econometric method to examine this question in the context of economics researchers. We learn that research teams with more collaborators tend to produce papers with higher impact, and without increasing individual costs of communication and coordination. This suggests the trend toward larger research teams in economics will continue.

We study the effect of public subsidies from the Hill-Burton program on hospital capacity, organization of the hospital industry, and utilization. We estimate that the program accounted for a net increase of over 70,000 beds nationwide and that these effects lasted well beyond twenty years. We also show that differences in the number of hospital beds per capita between high- and low-income counties, rural and urban counties, and the South and the rest of the country fell substantially. We conclude that the program largely achieved its goals, with substantial and long-lasting effects on the U.S. hospital industry.