The gravity model in economics was until relatively recently an intellectual orphan, unconnected to the rich family of economic theory. This review is a tale of the orphan's reunion with its heritage and the benefits that have flowed from it. Gravity has long been one of the most successful...

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...

The effects of geography and productivity on the global pattern of production are captured here in a specific factors gravity model. Simple enough for sharp results, the model is yet rich enough to contain the high dimensional productivity frictions in production and distribution of a many...

Most empirical policy work requires the aggregation of policies. Trade policy aggregation exemplifies the aggregation problem poignantly, with thousands of highly dispersed trade barriers. This paper provides methods of policy aggregation that are consistent with two common objectives of...

Contract enforcement is probabilistic, but the probability depends on rules and processes. A stimulus to trade may induce traders to alter rules or processes to improve enforcement. In the model of this paper, such a positive knock-on effect occurs when the elasticity of supply of traders is...

Mutual causation of predation and trade induces novel effects of commercial policy in this paper. The model can explain trade volume responses to market widening initiatives that are otherwise puzzlingly 'too big' or 'too small'. Efficient commercial policy (broadly defined) depends crucially on...

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...

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...

This paper rehabilitates the concept of effective rate of protection for use in political economy. The usual definition corresponds to no economically interesting magnitude in general equilibrium. The effective rate of protection for a sector is redefined here as the uniform tariff which is...

The standard theory of trade reform uses a passive government budget constraint, in which changes in tariff revenue are offset by changes in lump sum transfers. This paper offers a general framework for the analysis of trade reform when the government budget constraint is active, meaning that...