We develop a framework for studying trade in vertically and horizontally differentiated products. In our model, consumers with heterogeneous incomes and tastes purchase a homogeneous good as well as making a discrete choice of quality and variety of a differentiated product. The distribution of...

In an economy with imperfect labor contracts, differences in the distribution of human capital are an independent source of comparative advantage. I study a world economy with two sectors, one where output is produced by teams and another where individuals can work alone. When workers' abilities...

Using data assembled by the Global Environmental Monitoring System we examine the reduced-form relationship between various environmental indicators and the level of a country's per capita income. Our study covers four types of indicators: concentrations of urban air pollution; measures of the...

We study patterns of FDI in a multi-country world economy. We develop a model featuring non-homothetic preferences for quality and monopolistic competition in which specialization is purely demand-driven and the decision to serve foreign countries via exports or FDI depends on a...