We consider five models of international trade that belong to the class of models in which the trade elasticity and domestic trade share are sufficient statistics for the welfare cost of autarky. Three are fixed-variety models featuring increasing micro-level margins of adjustment: versions of the Armington model, the Ricardian model, and its variable-markup counterpart. Two are endogenous-variety models featuring monopolistic competition: versions of the Krugman model and the Melitz model. For the three fixed-variety models, we show theoretically that, although they imply the same mapping from the trade elasticity to welfare, they imply different mappings from the trade elasticity to observed order statistics of price gaps of identical goods across countries. This result implies that choosing the parameter that governs the elasticity of trade to match the same order statistics in the data differentially impacts each model’s measured welfare cost of autarky. We quantify these differences for all five models.
We provide a strategic model of the formation of production networks that subsumes the standard general equilibrium approach. The objective of firms in our setting is to choose their supply relationships so as to maximize their profit at the general equilibrium that unfolds. We show that this objective is equivalent to the maximization by the firms of their eigenvector centrality in the production network. As is common in network formation games based on centrality, there are multiple Nash equilibria in our setting. We have investigated the characteristics and the social efficiency of these equilibria in a stylized version of our model representing international trade networks. We show that the impact of network structure on social welfare is firstly determined by a trade-off between costs of increasing process complexity and positive spillovers on productivity induced by the diversification of the input mix. We further analyze a variant of our model that accounts for the risks of disruption of supply relationships. In this setting, we characterize how social welfare depends on the structure of the production network, the spatial distribution of risks, and the process of shock aggregation in supply chains. We finally show that simple trade policies characterized by sets of links that are either prevented or catalyzed can be a powerful equilibrium selection device.
This paper examines how offshoring shapes emissions leakage and global emissions in response to unilateral environmental policy. We use a general equilibrium offshoring model with heterogeneous firms, based on standard modeling assumptions, where firms allocate labor between production tasks and emissions abatement. We find that global emissions respond non-monotonically to a unilateral emissions tax increase: for small cross-country tax differentials, emissions fall; but as the difference widens, leakage exceeds 100%, raising global emissions due to a global technique effect. The cleanest domestic firms start offshoring and incumbent offshoring firms become dirtier under declining effective foreign taxes. We isolate the offshoring margin – one underexplored channel of leakage – and contrast our findings with comparable models of trade in final goods: the mode of globalization matters. Complementing the unilateral reform with a border carbon adjustment (BCA) prevents emissions leakage but may raise inequality between countries.
Customs data reveal the heterogeneity and granularity of relationships among buyers and sellers, showing how more exports to a destination break down into more firms selling there and more buyers per exporter. We develop a quantitative general equilibrium model of firm‐to‐firm matching that builds on this insight to separate the roles of iceberg costs and matching frictions in gravity. In the cross section, we find matching frictions as important as iceberg costs in impeding trade, and more sensitive to distance. Because domestic and imported intermediates compete directly with labor in performing production tasks, our model also fits the heterogeneity of labor shares across French producers. Applying the framework to the 2004 expansion of the European Union, reduced iceberg costs and reduced matching frictions contributed equally to the increase in French exports to the new members. While workers benefited overall, those competing most directly with imports gained less, even losing in some countries entering the EU.