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...

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...

This chapter surveys recent developments in agglomeration theory within a unifying framework. We highlight how locational fundamentals, agglomeration economies, the spatial sorting of heterogeneous agents, and selection effects affect the size, productivity, composition, and inequality of...

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...