Optimal Collusion-Proof Auctions

We study an optimal collusion-proof auction in an environment where subsets of bidders may collude not just on their bids but also on their participation. Despite their ability to collude on participation, informational asymmetry facing the potential colluders can be exploited significantly to weaken their collusive power. The second-best auction --- i.e., the optimal auction in a collusion-free environment --- can be made collusion-proof, if at least one bidder is not collusive, or there are multiple bidding cartels, or the second-best outcome involves a nontrivial probability of the object not being sold. In case the second-best outcome is not weak collusion-proof implementable, we characterize an optimal collusion-proof auction. This auction involves nontrivial exclusion of collusive bidders --- i.e., the object is not sold to any collusive bidder with positive probability.

Lawyer Advising in Evidence Disclosure

This paper examines how the advice that lawyers provide to their clients affects the disclosure of evidence and the outcome of adjudication, and how the adjudicator should allocate the burden of proof in light of these effects. Despite lawyers' expertise in assessing the evidence, their advice is found to have no effect on adjudication, if the lawyers follow disclosure strategies that are undominated in a certain sense. A lawyer's advice can influence the outcome to his client's favor, if he can credibly advise his client to suppress some favorable evidence, but this effect is socially undesirable.

Revenue Comparisons for Auctions When Bidders Have Arbitrary Types

This paper develops a methodology for characterizing expected revenue from auctions in which bidders' types come from an arbitrary distribution. In particular, types may be multidimensional, and there may be mass points in the distribution. One application extends existing revenue equivalence results. Another application shows that first-price auctions yield higher expected revenue than second-price auctions when bidders are risk averse and/or face financial constraints. This revenue ranking also extends to risk-averse bidders with general forms of non-expected utility preferences.

Strategic Judgment Proofing

A liquidity-constrained entrepreneur needs to raise capital to finance a business activity that may cause injuries to third parties --- the tort victims. Taking the level of borrowing as fixed, the entrepreneur finances the activity with senior (secured) debt in order to shield assets from the tort victims in bankruptcy. Interestingly, senior debt serves the interests of society more broadly: it creates better incentives for the entrepreneur to take precautions than either junior debt or outside equity. Unfortunately, the entrepreneur will raise a socially excessive amount of senior debt, reducing his incentives for care and generating wasteful spending. Giving tort victims priority over senior debtholders in bankruptcy prevents over-leveraging but leads to suboptimal incentives. Lender liability exacerbates the incentive problem even further. A Limited Seniority Rule, where the firm may issue senior debt up to an exogenous limit after which any further borrowing is treated as junior to the tort claim, dominates these alternatives. Shareholder liability, mandatory liability insurance and punitive damages are also discussed.

The Hold-up Problem

Hold-up arises when part of the return on an agent’s relationship-specific investments is ex post expropriable by his trading partner. The hold-up problem has played an important role as a foundation of modern contract and organization theory, as the associated inefficiencies have justified many prominent organizational and contractual practices. We formally describe the main inefficiency hypothesis and sketch out the remedies suggested, as well as the more recent re-examination of the relevance of these theories.

A Dynamic Theory of Holdup

The holdup problem arises when parties negotiate to divide the surplus generated by their ex ante noncontractable investments. We study this problem in a model which, unlike the stylized static model, allows the parties to continue to invest until they agree on the terms of trade. These possible investment dynamics overturn the conventional wisdom dramatically. First, the holdup problem need not entail underinvestment-type inefficiencies when the parties are sufficiently patient. Second, inefficiencies can arise unambiguously, but the reason for their occurrence differs from the one recognized by the static model. This latter finding sheds new light on the design of contracts and organizations.Investment, Bargaining with an endogenous pie, contribution games.

Opinion as Incentives

We study a model where a decision maker (DM) must select an adviser to advise her about an unknown state of the world. There is a pool of available advisers who all have the same underlying preferences as the DM; they differ, however, in their prior beliefs about the state, which we interpret as differences of opinion. We derive atradeoff faced by the DM: an adviser with a greater difference of opinion has greater incentives to acquire information, but reveals less of any information she acquires, via strategic disclosure. Nevertheless, it is optimal to choose an adviser with at least some difference of opinion. The analysis reveals two novel incentives for an agent to acquire information: a ``persuasion'' motive and a motive to ``avoid prejudice.'' Delegation is costly for the DM because it eliminates both of these incentives. We also study the relationship between difference of opinion and difference of preference.

Market versus Non-Market Assignment of Initial Ownership

We study the initial assignment of ownership of a good. When the good is sold at the market-clearing price, wealthy agents may acquire it instead of poor agents who value it more highly, all else equal. Non-market assignment schemes such as random rationing may allocate the good more efficiently than the competitive market would --- if recipients of the good are allowed to resell. Schemes that favor the poor are even more desirable in that context. The ability to resell is critical to the results, but resale induces speculators to participate, so regulation of resale may be beneficial.