Recent research in international trade emphasizes the importance of firms' extensive margins for understanding overall patterns of trade as well as how firms respond to specific events such as trade liberalization. In this paper, we use detailed US trade statistics to provide a broad overview of...

We introduce quality differentiation and an extensive margin of products into a standard quantitative, general equilibrium model of international trade. Both the quality and the quantity of a product play a role in its contribution both to consumption and to production. The framework allows...