Micro-level data have had a profound in ‡uence on research in international trade over the last ten years. In many regards, this research agenda has been very successful. New stylized facts have been uncovered and new trade models have been developed to explain these facts. In this paper we investigate to which extent answers to new micro-level questions have a¤ected answers to an old and central question in the …eld: How large are the welfare gains from trade? A crude summary of our results is: "So far, not much."

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 considerations-market structure, firm-level heterogeneity, multiple sectors, intermediate goods, and multiple factors of production-affect the magnitude of the gains from trade liberalization. We conclude by discussing a number of outstanding issues in the literature as well as alternative approaches for quantifying the consequences of globalization.

Micro-level data have had a profound influence on research in international trade over the last ten years. In many regards, this research agenda has been very successful. New stylized facts have been uncovered and new trade models have been developed to explain these facts. In this paper we investigate to which extent answers to new micro-level questions have affected answers to an old and central question in the field: How large are the gains from trade? A crude summary of our results is: "So far, not much."