The traditional trade theory predicts that trade in goods perfectly substitutes for direct movement of factors. This equivalence between goods trade and factor movements, however, depends crucially on assumptions about the production. This paper establishes necessary and sufficient conditions...

I study knowledge spillovers, positive externalities that augment the information set of an economic agent, and reviews the evidence on such spillovers in the context of international economic transactions. Even though spillovers are by their very nature difficult to identify, over recent...