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,...

Are developing-world cities engines of opportunities for low-wage earners? In this study, we track a cohort of young low-income workers in Brazil for thirteen years to explore the contribution of factors such as industrial structure and skill segregation on upward income mobility. We find that...

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...

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...

We study the determinants of the location of sub-contracted activity in a general equilibrium model of outsourcing and trade. We model outsourcing as an activity that requires search for a partner and relationship-specific investments that are governed by incomplete contracts. The extent of...

In a static setup, migration of unskilled labor may be resisted by the entire native-born population because, being relatively low earners, migrants are net beneficiaries of the fiscal system. However, the paper shows that with a pay-as-you-go pension, an important pillar of the welfare state,...

We develop a dynamic politico-economic theory of welfare state and immigration policies, featuring three groups of voters: skilled workers, unskilled workers, and old retirees. The welfare-state is modeled by a proportional tax on labor income to finance a demogrant in a balanced-budget manner...

We develop a framework for studying trade in vertically and horizontally differentiated products. In our model, consumers with heterogeneous incomes and tastes purchase a homogeneous good as well as making a discrete choice of quality and variety of a differentiated product. The distribution of...

We develop a dynamic politico-economic theory of welfare state, featuring three groups of voters: skilled workers, unskilled workers, and old retirees. The welfare-state is modeled by a proportional tax on labor income to finance a demogrant in a balanced-budget manner to capture the essence of...