The gravity equation in international trade is one of the most robust empirical finding in economics: bilateral trade between two countries is proportional to size, measured by GDP, and inversely proportional to the geographic distance between them. While the role of size is well understood, the...

We propose a new sufficient statistic to measure the ex-post welfare gains from trade in CES models featuring any productivity distribution or pattern of selection into production and exporting. Our statistic is based on a single data moment, the change in the market share of continuing domestic...

We propose a new sufficient statistic to measure the gains from trade in models where the extensive margin trade elasticity is not necessarily constant. This statistic is a function of one data moment, the market share of continuing domestic products, and one parameter, the elasticity of...

By considering a model with identical firms, Paul Krugman (1980) predicts that a higher elasticity of substitution between goods magnifies the impact of trade barriers on trade flows. In this paper, I introduce firm heterogeneity in a simple model of international trade. When the distribution of...

The gravity equation in international trade is one of the most robust empirical finding in economics: bilateral trade between two countries is proportional to size, measured by GDP, and inversely proportional to the geographic distance between them. While the role of size is well understood, the...