We show that in the case of multiple goods and factors, the factor proportions theory has the following prediction: across industries, the impacts of the endowment of a given factor on industry outputs have positive co-variance with the relative uses of this factor. The intuition is that on...

Dramatic changes are occurring in the nature of international trade. Production processes increasingly involve a sequential, vertical trading chain stretching across many countries, with each country specializing in particular stages of a good's production sequence. We document a key aspect of...

A major feature of globalization has been the enormous increase in international flows of goods and services: countries are now trading much more with each other. In this article, the authors demonstrate the greater role vertical specialization is playing in these increased flows. Vertical...

We examine why the gravity equation works and the implications for its use. First, we demonstrate that the gravity equation as a statistical relationship can be generated from a model with incomplete specialization and trade costs. Second, we analyse the predominance of zero bilateral trade...