In three chapters I study the formation of social networks, and the impact the structures that arise may have in various economic settings. First, I develop a model of social network formation with heterogeneous agents and incomplete information. The model predicts an equilibrium in which agents...

In this dissertation I examine a set of crucial topics in the political economy of international trade, with an emphasis on firm-level heterogeneity. The first chapter is an empirical study of the new trade theories in which firm heterogeneity and trade costs play central roles in shaping the...