International economic integration yields large potential welfare effects, even in a static constant returns competitive world economy. Our method is novel. The effect of border barriers on trade flows is often inferred from gravity models. But their rather atheoretic structure precludes welfare...

Market exchange is subject to an endogenously determined level of predation which impedes specialization and gains from trade. We construct a model in which utility-maximizing agents opt between careers in production and careers in predation. Three types of equilibria may emerge: autarky (with...

Why does illegal trade often flourish without formal enforcement, but sometimes fail? Why do illegal trade-reducing policies often fail? Why do States often appear to tolerate illegal trade? A model of trade with cops and robbers provides answers. `Safety in numbers' is a key element: the...

Does globalization widen inequality or increase income risk? In the specific factors continuum model of this paper, globalization widens inequality, amplifying the positive (negative) premia for export (import- competing) sectors. Globalization amplifies the risk from idiosyncratic relative...

This paper provides striking confirmation of the restrictions of the structural gravity model of trade. Structural forces predicted by theory explain 95% of the variation of the fixed effects used to control for them in the recent gravity literature, fixed effects that in principle could reflect...

We estimate geographic barriers to export trade in nine service categories for Canada's provinces from 1997 to 2007 using the structural gravity model. Constructed Home, Domestic and Foreign Bias indexes (the last two new) capture the direct plus indirect effect of services trade costs on...

What kind of tariff reform is likely to raise welfare in situations where tariff revenue is important? Uncertainty about specification and risk from imprecise parameter estimates of any particular specification reduce the credibility of simulation estimates. A promising alternative is to develop...

Weak states enable private enforcement but it does not always fade away in the presence of strong states. We develop a general equilibrium model of the market organization of enforcers (self-enforcers, competitive specialized enforcers or monopoly) who defend endowments from predators. We...

The gravity model has been widely used to infer substantial trade flow effects of institutions such as customs unions and exchange rate mechanisms. McCallum [1995] found that the US-Canada border led to trade between provinces that is a factor 22 (2,200%) times trade between states and...

There is widespread concern that the Uruguay Round may reduce the welfare of developing countries through its effect on world agricultural prices. Reduced agricultural price distortions among major supplying nations are predicted to increase basic food prices and decrease some important export...