Aside from the equilibrium that Hotelling (1931) displayed, his model of non-renewable resources also contains a continuum of bubble equilibria. In all the equilibria the price of the resource rises at the rate of interest. In a bubble equilibrium, however, the consumption of the resource peters...

The rise in world trade since 1970 has raised international mobility of labor services. We study the effect of such a globalization of the world's labor markets. We find that when people can choose between wage work and managerial work, the output gains are U-shaped: A worldwide labor market...

We ask what level of migration would maximize world welfare. We find that skill-neutral policies are never optimal. An egalitarian welfare function induces a policy that entails moving mainly unskilled immigrants into the rich countries, whereas a welfare function skewed highly towards the rich...

Most industries go through a "shakeout" phase during which the number of producers in the industry declines. Industry output generally continues to rise, however, which implies a reallocation of capacity from exiting firms to incumbents and new entrants. Thus shakeouts seem to be classic...

In a growth model, rent-grabbing and free riding can give rise to inequality in productivity and firm size. Inequality among firms affects a firm's incentive to free ride or to grab rents, and, hence, the incentive to invest in research and training We follow Lucas and Prescott (1971) and...

We reexamine several bodies of data on the growth of output, labor, and capital, within the context of a model that admits the possibility of an externality to the capital input. The model is an augmented version of Paul Romer's (1987) reformulation of the Solow model. Unlike Romer, however, we...