We model imperfect contract enforcement when repudiators and their victims default to spot trading. The interaction between the contract and spot markets under improved enforcement can exacerbate repudiation and reduce contract execution, harming all traders. Improved contract execution benefits...

Without the rule of law, traders who incur trading costs can be held up by counter-parties who are stronger in anarchic bargaining. The favourable terms which the latter extract can overcrowd that side of the market, dissipating the benefits. We establish plausible necessary and sufficient...

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...

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...

Government budget balance forces the endogenous use of distortionary tax instruments" when an exogenous reform is implemented. The aggregate efficiency of such reforms is based" on comparisons of simple summary measures of the Marginal Cost of Funds of the various tariff" or quota changes with...