Most economic activity occurs in cities. This creates a tension between local increasing returns, implied by the existence of cities, and aggregate constant returns, implied by balanced growth. To address this tension, we develop a theory of economic growth in an urban environment. We show how...

A large number of pairs of countries exhibit a dynamic pattern in which: (i) Fertility in both countries declines across time; (ii) Initially one country has higher fertility and lower per-capita income compared to the other; (iii) In time, as per-capita income converges, fertility rates in the...