We propose a simple model of trade outside the law preyed on by robbers and possiblyprotected by private cops. We establish the conditions for trade collapse, secure trade andinsecure trade. Endogenous predation and enforcement can explain both puzzling failures ofcommonly observed state...

The high trade costs inferred from gravity are rarely used in thewide class of trade models. Two related problems explain this omis-sion of a key explanatory variable. First, national seller and buyer re-sponses to trade costs depend on their incidence rather than on the fullcost. Second, the...

The fact that raising taxes can increase taxed labor supply through income effects is frequently used to justify greater public good provision than indicated by traditional, compensated analyses. We develop a model including multiple public goods and taxes and derive consistent measures of the...

Most empirical policy work requires the aggregation of policies. Trade policyaggregation exemplifies the aggregation problem poignantly, with thousands of highlydispersed trade barriers. This paper provides methods of policy aggregation that areconsistent with two common objectives of empirical...