In this paper, we merge the heterogenous firm trade model of Melitz (2003) with the Ricardian model of Dornbusch, Fisher and Samuelson (DFS 1977) to explain how the pattern of international specialization and trade is determined by the interaction of comparative advantage, economies of scale,...

This paper investigates the effects of mergers on the product mix of multiproduct firms. Thus, we open the black box of post-merger efficiency improvements to reveal a new margin of adjustment along the product dimension. We analyze horizontal mergers in a theoretical model where oligopolistic...

Short run gravity is a geometric weighted average of long run gravity and bilateral capacity. The model features (i) joint trade costs endogenous to bilateral volumes, (ii) long run gravity as a limiting case of effcient investment in bilateral capacities, (iii) a structural ratio of short run...

In this paper we examine the empirical relevance of three prominent endogenous protection models. Is protection for sale, or do altruistic policy makers worry about political support? We find strong evidence that protection is indeed for sale. The important new result is, however, that not only...

We analyze a two country-two good model of international trade in which citizens in each country differ by their specific factor endowments. The trade policy in each country is set by the politician who has been elected by the citizens in a previous stage. Due to a delegation effect citizens...

This paper investigates the contractual choice between exclusive dealing and common agency in a simple international oligopoly model where products are sold through intermediaries. We find that when trade barriers are high domestic firms tend to adopt exclusive dealing contracts, whereas trade...

We study infant industry protection using a dynamic model in which the industry's cost is initially higher than that of foreign competitors. The industry can stochastically lower its cost via learning by doing. Whether the industry has transitioned to low cost is private information. We use a...

This paper examines how skill-biased growth can generate economic fragmentation (income disparities) that give rise to social fragmentation (the adoption of increasingly incompatible social identities and values), which generate political fragmentation (the adoption of increasingly incompatible...

We develop a method to measure the incidence of monopolistic markup distortions in the global economy. Using semi-parametric formulas, we measure how trade modifies the deadweight loss of markups through two channels: (1) trade-induced change in markup dispersion, and (2) international...