We derive a simple equation to calculate the global welfare impact of the simultaneous reduction of trade costs between multiple country-pairs. Interestingly, we find that we obtain the same equation for a broad class of trade models. Moreover, balanced trade is mostly not required for the...

I present a model of two quantity-setting firms, each producing two goods in a different country, but enjoying a competitive advantage in only one of them. An international cartel can either shut down trade and manufacture both goods domestically or foreclose the inefficient plant and import the...

Is the variation in bilateral trade flows across countries primarily due to differences in the number of exporting firms (the extensive margin) or in the average size of an exporter (the intensive margin)? And how does this affect the estimation and quantitative implications of the Melitz (2003)...

We review a recent body of theoretical work that aims to put numbers on the consequences of globalization. A unifying theme of our survey is methodological. We rely on gravity models and demonstrate how they can be used for counterfactual analysis. We highlight how various economic...

This chapter reviews the new approach to international trade based on firm heterogeneity in differentiated product markets. This approach explains a variety of features exhibited in disaggregated trade data, including the higher productivity of exporters relative to non-exporters,...

What has been the overall global welfare impact of the accession to the World Trade Organization of a large country like China, or the global welfare impact of the completion of the Uruguay round of GATT negotiations? Can we come up with a simple user-friendly formula to calculate the global...

Recent quantitative trade models treat import tariffs as pure cost shifters so that their effects are similar to iceberg trade costs. We introduce revenue-generating import tariffs, which act as demand shifters, into the framework of Arkolakis, Costinot and Rodriguez-Clare (2012), and generalize...

The Melitz model highlights the importance of the extensive margin (the number of firms exporting) for trade flows. Using the World Bank's Exporter Dynamics Database (EDD) featuring firm-level exports from 50 countries, we find that around 50 percent of variation in exports is along the...

Recent quantitative trade models treat import tariffs as pure cost shifters so that their effects are similar to iceberg trade costs. We introduce revenue-generating import tariffs, which act as demand shifters, into the framework of Arkolakis, Costinot and Rodriguez-Clare (2012), and generalize...

Recent quantitative trade models treat import tariffs as pure cost shifters so that their effects are similar to iceberg trade costs. We introduce revenue-generating import tariffs, which act as demand shifters, into the framework of Arkolakis, Costinot and Rodriguez-Clare (2012), and generalize...