We propose a simple and flexible reduced-form econometric approach to estimate gravity models in the short and the long run. The theoretical lens for interpreting our methods amends the canonical Lucas-Prescott adjustment formulation to allow for time-interval-varying...

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...

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...

This paper surveys the measurement of trade costs --- what we know, and what we don't know but may usefully attempt to find out. Partial and incomplete data on direct measures of costs go together with inference on implicit costs from trade flows and prices. Total trade costs in rich countries...

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...

Much economic policy is deliberately shifted away from direct political processes to administrative processes --- political pressure deflection. Pressure deflection poses a puzzle to standard political economy models which suggest that having policies to `sell' is valuable to politicians. The...

We show that the effects of tariff changes on welfare and import volume can be fully characterized by their effects on the generalized mean and variance of the tariff distribution. Using these tools, we derive new results for welfare- and market-access-improving tariff changes, which imply two...

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...

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...

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...