Recent theoretical developments have incorporated endogenous multinational firms into the general-equilibrium model of trade. One simple taxonomy separates the theory into vertical' models in which firms geographically separate activities by stages of production and horizontal' models of...

In this paper we examine how to account for growth when new inputs are being created. In particular, we obtain a decomposition of growth into that due to a higher quantity of existing inputs, and that due to a greater range of inputs. This decomposition is first obtained for a single firm, with...

Recent theoretical developments have incorporated endogenous multinational firms into the general-equilibrium model of trade. One simple taxonomy separates the theory into vertical' models in which firms geographically separate activities by stages of production and horizontal' models of...

Recent theoretical developments have incorporated endogenous multinational firms into the general-equilibrium model of trade. One simple taxonomy separates the theory into "vertical" models, in which firms geographically separate activities by stages of production, and "horizontal" models, in...

This paper argues that the theoretical foundations for the gravity equation are general, while the empirical performance of the gravity equation is specific to the type of goods examined. Most existing theory for the gravity equation depends on the assumption of differentiated goods. We show...