existence of cities, and aggregate constant returns, implied by balanced growth. To address this tension, we develop a theory of … described by a power distribution with coefficient one: Zipf's Law. Under certain assumptions our theory produces Zipf's Law …

equilibrium theory of economic growth in an urban environment. In our theory, variation in the urban structure through the growth … aggregate. We show that, consistent with the data, the theory produces a city size distribution that is well approximated by …