Efficient collusion in optimal auctions

We study collusion in an IPV auction with binary type spaces. Collusion is organized by a third party that can manipulate participation decisions. We characterize the optimal response of the seller to different threats of collusion among the bidders. We show that, contrary to the prevailing view that asymmetric information imposes transaction costs in side contracting, collusion in the optimal auction is efficient when the third party can implement monetary transfers as well as when it can implement monetary transfers and reallocations of the good. The threat of non-participation in the auction by a subset of bidders is crucial in constraining the seller's profit.     

Mutual supervision in preshipment inspection programs

Preshipment inspection (PSI) programmes are implemented in many developing countries to assist governments in the collection of revenue at their borders. These programs consist of the delegation of the inspection of imports to a private firm. To study these PSI programmes, we develop a hierarchical agency model in which the government authority can rely on two supervisors, namely the private inspection firm and the customs administration, to control importers' declarations. The government's optimal contract is fully characterized. We devote some attention to the inspection policy and its comparative statics properties. In particular, we identify the situations in which PSI programmes are revenue enhancing. We also discuss the reconciliation policy, i.e. what to do in case of conflicting inspection reports by the inspection firm and the customs administration. In the optimal mechanism, mutual supervision between the inspection firm and the customs administration is used to provide adequate incentives to all parties.