The received economic wisdom is that cities are too big and that public policy should limit their sizes. This wisdom assumes, unrealistically, that city sites are homogeneous, migration is unfettered, land is given freely to incoming migrants, and federal taxes are neutral. Should those...

The aim of this article is twofold. First, we present an integrative framework that encompasses a large share of existing neg models. This framework allows us to discuss the fundamental assumptions and the key results that hold throughout a broad class of models. We argue that progress within...

Large cities produce more output per capita than small cities. This higher productivity may occur because more talented individuals sort into large cities, because large cities select more productive entrepreneurs and firms, or because of agglomeration economies. We develop a model of systems of...

We develop a framework that integrates natural advantage, agglomeration economies, and firm selection to explain why large cities are both more productive and more unequal than small towns. Our model highlights interesting complementarities among those factors and it matches a number of key...