The growth in the trade share of output is one of the most important features of the world economy since World War II. The growth is generally thought to have been generated by falling tariff barriers worldwide. This thinking, however, does not square with standard static and dynamic...

A large empirical literature finds that there is too little international trade, and too much intra-national trade to be rationalized by observed international trade costs such as tariffs and transport costs. The literature uses frameworks in which goods are assumed to be produced in just one...