We propose a methodology for studying changes in bilateral commodity trade due to goods not exported previously or exported only in small quantities. Using a panel of 1,900 country pairs, we find that increased trade of these “least-traded goods” is an important factor in trade growth. This extensive margin accounts for 10 percent of the growth in trade for NAFTA country pairs, for example, and 26 percent in trade between the United States and Chile, China, and Korea. Looking at country pairs with no major trade policy change or structural change, however, we find little change in the extensive margin.

In what order should a developing country adopt policy reforms? Do some policies complement each other? Do others substitute for each other? To address these questions, we develop a two-country dynamic general equilibrium model with entry and exit of firms that are monopolistic competitors. Distortions in the model include barriers to entry of firms, barriers to international trade, and barriers to contract enforcement. We find that a reform that reduces one of these distortions has different effects depending on the other distortions present. In particular, reforms to trade barriers and barriers to the entry of new firms are substitutable, as are reforms to contract enforcement and trade barriers. In contrast, reforms to contract enforcement and the barriers to entry are complementary. Finally, the optimal sequencing of reforms requires reforming trade barriers before contract enforcement.

This paper develops a methodology for predicting the impact of trade liberalization on exports by industry (3-digit ISIC) based on the pre-liberalization distribution of exports by product (5-digit SITC). Using the results of Kehoe and Ruhl (2013) that much of the growth in trade after trade liberalization is in products that are traded very little or not at all, we predict that industries with a higher share of exports generated by least traded products will experience more growth. Using our methodology, we develop predictions for industry-level changes in trade for the United States and Korea following the U.S.-Korea Free Trade Agreement (KORUS). As a test for our methodology, we show that it performs significantly better than the applied general equilibrium models originally used for the policy evaluation of the North American Free Trade Agreement (NAFTA).