The Optimal Consumption and the Quitting of Harmful Addictive Goods

In this paper we study a model of rational consumption and quitting in the context of harmful addictive goods. We assume that a person has imperfect information about his ability to resist and terminate the addiction. We first characterize the optimal consumption path of a non-addicted person, along which his stock of the addictive substance is either always increasing (and thus addiction occurs stochastically), always decreasing, or always unchanged. We then characterize the optimal consumption path of an addicted person, along which he may attempt to quit the addiction for a period of time, and then resume his consumption if the attempt is unsuccessful. Finally, we remark on the issues of regret, multiple attempts to quit, and quitting programs.

Market Design with Correlated Valuations

The effects of information on market design are explored in a simple setting where firms have private information about their correlated fixed costs and the government aims to maximize its expected revenue conditional on achieving efficient allocations. Government revenues are higher when the costs are less correlated (or are more of a private value). The reduced correlation increases the firms' information rents, but a change in the information structure also changes the expected market structures with positive effects on government revenues. If the government faces the no-deficit constraint, there are situations where efficient allocations are achieved under asymmetric information but not under symmetric information.market structure, correlated values, market design, government revenue

Switching Costs in Infinitely Repeated Games

We show that small switching costs can have surprisingly dramatic effects in infinitely repeated games if these costs are large relative to payoffs in a single period. This shows that the results in Lipman and Wang [2000] do have analogs in the case of infinitely repeated games. We also discuss whether the results here or those in Lipman and Wang [2000] imply a discontinuity in the equilibrium outcome correspondence with respect to small switching costs. We conclude that there is not a discontinuity with respect to switching costs but that the switching costs do create a discontinuity with respect to the length of a period.infinite horizon, repeated games, switching costs, Folk Theorem

Common Value Auctions with Return Policies

This paper examines the role of return policies in common value auctions. We first characterize the unique symmetric equilibrium in first-price and second-price auctions with continuous signals and discrete common values when certain return policies are provided. We then examine how the return policies affect a seller's revenue. When the lowest common value is zero, a more generous return policy generates a higher seller's revenue; the full refund policy extracts all the surplus and therefore implements the optimal selling mechanism; given any return policy, a second-price auction generates a higher revenue than a first-price auction. In a second-price auction where the lowest common value is not zero but still smaller than the seller's reservation value, then a more generous return policy also generates a higher revenue; otherwise, the optimal return policy could be a full refund, no refund or partial refund policy.auctions, return policies, refund

Rationalizing Irrational Beliefs

In this paper, we re-examine various previous experimental studies of the Centipede Game in the literature. These experiments found that players rarely follow the subgame-perfect equilibrium strategies of the game, and various modifications to the game were proposed to explain the outcomes of the experiments. We here offer yet another modification. Players have a choice of whether or not to believe that their opponents use subgame-perfect equilibrium strategies. We define a `behavioral equilibrium' for this game. This equilibrium concept can reproduce the outcomes of those experiments.centipede games, game theory, experimental economics, behavioral economics

Strategic Buybacks of Sovereign Debt

We consider a transaction costs model of sovereign debt buybacks. We show that both secret and publicly known buybacks are profitable for the debtor country. Furthermore, the government of the debtor country would like to spend all of its initial endowment to buy back its debt as soon as possible. When the initial endowment of the government is publicly known, the equilibrium outcome of the secret buyback model is the same as in the public buyback model. However, the equilibrium outcomes are different when the initial endowment is private information of the government. Under reasonable conditions, the secondary market price under publicly observable buybacks is lower than the price under secret buybacks. Therefore the government prefers the former over the latter when the initial endowment is not commonly known.Secret buybacks, International debt, Secondary markets

Signally by Jump Bidding in Private Value Auctions

This paper examines how a bidder can benefit from jump bidding by using the jump bid as a signal of a high valuation which causes other bidders to drop out of the auction earlier than they would otherwise. The information contained in a jump bid must be sufficient to induce a discrete change in the bidding behaviour of the other bidders. In an auction for a single item, a jump bid signals both the identity and the high valuation of a bidder. The existence of a beneficial jump bid equilibrium requires a gap in the distribution of the jump bidder and her identity must be concealed. Concealing the identity of the bidders permits the jump bidder to signal more information through the jump bid and thus she can benefit more from it. In an auction for multiple items, the jump bid signals a high valuation by the jump bidder.Auction, Jump Bidding

Endogenous Coalition Formation in Rivalry

This paper studies endogenous coalition formation in an environment where continuing conflict exists. A number of players compete for an indivisible prize and the probability of winning for a player depends on his initial resource as well as the distribution of initial resources among the other players. Players can pool their resources together to increase their probabilities of winning through coalition formation. If a coalition wins, the players in the coalition will further compete and possibly form new coalitions. The game continues until one individual winner is left. We determine subgame perfect equilibria for the game of three or four players and provide conditions under which the equilibrium coalition structures involve a balance of power. We also illustrate that there can be no equilibrium coalition structure. Our analysis sheds some lights on problems of temporary cooperation among heterogeneous individuals who are rivals in nature.Coalition formation,Conflicts,Rivalry

Learning Buyers' Valuation Distribution in Posted-Price Selling

A dynamic pricing model is studied where a seller of an asset faces a sequence of potential buyers whose valuation distribution is unknown to the seller. The seller learns more about the distribution in the selling process and becomes less optimistic as time passes by. We characterize the optimal posted prices which incorporate the newly updated belief every period and derive conditions under which these prices are declining over time. A counter-example is provided to demonstrate that there can be situations where the optimal prices actually increase over time.Price determination, Posted-price selling, Learning

Switching Costs in Frequently Repeated Games

We show that the standard results for finitely repeated games do not survive the combination of two simple variations on the usual model. In particular, we add a small cost of changing actions and consider the effect of increasing the frequency of repetitions within a fixed period of time. We show that this can yield multiple subgame perfect equilibria in games like the Prisoners' Dilemma which normally have a unique equilibrium. Also, it can yield uniqueness in games which normally have multiple equilibria. For example, in a two by two coordination game, if the Pareto dominant and risk dominant outcomes coincide, the unique subgame perfect equilibrium for small switching costs and frequent repetition is to repeat this outcome every period. Also, in a generic Battle of the Sexes game, there is a unique subgame perfect equilibrium for small switching costs.Repeated games, Switching costs, Folk theorems