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...

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...

We propose an economic model of business groups that allows for the cooperative behavior of groups of firms, where the number and size of each group is determined endogenously. In this framework, more than one configuration of groups can arise in equilibrium: several different types of business...