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 formulate a two-country model with monopolistic competition and heterogeneous firms to reconsider labor market linkages in open economies. Labor-market imperfections arise by virtue of country-specific real minimum wages. Two principal experiments are considered. First, we show that trade...

We extend an analytical general equilibrium model of environmental policy with pre-existing labor tax distortions to include pre-existing monopoly power as well. We show that the existence of monopoly power has two offsetting effects on welfare. First, the environmental policy reduces monopoly...

Using a sample of Harvard undergraduates, we analyze trust and social capital in two experiments. Trusting behavior and trustworthiness rise with social connection; differences in race and nationality reduce the level of trustworthiness. Certain individuals appear to be persistently more...

We study the distributional effects of a pollution tax in general equilibrium, with general forms of substitution where pollution might be a relative complement or substitute for labor or for capital in production. We find closed form solutions for pollution, output prices, and factor prices....