There is a strong connection between per worker productivity and metropolitan area population, which is commonly interpreted as evidence for the existence of agglomeration economies. This correlation is particularly strong in cities with higher levels of skill and virtually non-existent in less...

Empirical research on cities starts with a spatial equilibrium condition: workers and firms are assumed to be indifferent across space. This condition implies that research on cities is different from research on countries, and that work on places within countries needs to consider population,...

Understanding how productivity varies with age is important for a variety of reasons. A decline in productivity with age implies that aging societies must increasingly depend on the labor supply of the young and middle age. It also means that policies designed to keep the elderly in the work...

Historically, urban growth required enough development to grow and transport significant agricultural surpluses or a government effective enough to build an empire. But there has been an explosion of poor mega-cities over the last thirty years. A simple urban model illustrates that in closed...

Recent theories of economic growth, including Romer (1986), Porter (1989) and Jacobs (1969), have stressed the role of technological spillovers in generating growth. Because such knowledge spillovers are particularly effective in cities, where communication between people is more extensive, data...

This paper shows how changes in generational accounts relate to the generational incidence of fiscal policy. To illustrate the relationship, it uses the Auerbach-Kotlikoff Dynamic Life-Cycle Simulation Model to compare policy-induced changes in generational accounts with actual changes in...

This paper studies the macroeconomic and efficiency effects of privatizing social security. It does so by simulating alternative privatization schemes using the Auerbach-Kotlikoff Dynamic Life-Cycle Model. The simulations indicate three things. First, privatizing social security can generate...

We investigate optimal consumption, asset accumulation and portfolio decisions in a realistically calibrated life-cycle model with flexible labor supply. Our framework allows for wage rate uncertainly, variable labor supply, social security benefits and portfolio choice over safe bonds and risky...