Serial cost sharing of excludable public goods: general cost functions

Summary. A group of individuals meet to share the cost and determine output allocations of a partial-excludable public good. We demonstrate that, for general cost functions and preferences that satisfy the Spence-Mirlees sorting condition, the serial cost-sharing formula (Moulin, 1994) has remarkable incentive properties. First, a direct economic mechanism that uses the serial formula is coalition strategy-proof, envy-free and satisfies the stand-alone property. Second, the serial mechanism involves partial exclusion, which is important for the reduction of the free-rider problem. Received: June 10, 1996; revised version; February 11, 1997     

Inefficient lobbying,populism and oligarchy

This paper analyzes the efficiency consequences of lobbying in a production economy with imperfect commitment. We first show that the Pareto efficiency result found for truthful equilibria of common agency games in static exchange economies no longer holds under these more general conditions. We construct a model of pressure groups where the set of efficient truthful common agency equilibria has measure zero. Second, we show that, under fairly general assumptions, the equilibrium will be biased against the group with the highest productivity of private capital, reflecting the fact that, on the margin, less productive groups find lobbying relatively more rewarding. Finally, as an application, if lobbies representing the “poor” and the “rich” have identical organizational capacities, we show that the equilibrium is biased towards the poor, who have a comparative advantage in politics, rather than in production. If the pressure groups differ in their organizational capacity, both pro-rich (oligarchic) and pro-poor (populist) equilibria may arise, all of which are inefficient with respect to the constrained optimum.     

Self-Fulfilling Mechanisms in Bayesian Games

Amechanismfor a Bayesian gameGis a mapping μ from the set of states of nature to the set of players' actions. μ isself-fulfillingif players are truthful at the communication stage and, given the information revealed by μ, no player can gain in unilaterally deviating from the action prescribed by the mechanism. We investigate the properties of self-fulfilling mechanisms and we show in particular that they correspond to inert solutions of the infinitely repeated game generated byG. We also discuss applications to market games, regulation, and R&D games.Journal of Economic LiteratureClassification Numbers: D82, C72.     

Choosing and sharing

Implementing a project, like a nationwide nuclear waste disposal, which benefits all involved agents but brings major costs only to the host is often problematic. In practice, revelation issues and redistributional concerns are significant obstacles to achieving stable agreements. We address these issues by proposing the first mechanism to select the efficient site (the host with the lowest cost) while simultaneously allowing for the implementation of any individually rational division of the whole hosting cost. The subgame perfect Nash equilibria of our simple mechanism are efficient, budget-balanced and individually rational. Moreover, the truthful equilibrium is immune to coalitional deviations.     

Individually rational, budget-balanced mechanisms and allocation of surplus

We investigate the issue of implementation via individually rational ex-post budget-balanced Bayesian mechanisms. We show that all decision rules generating a nonnegative expected social surplus are implementable via such mechanisms if and only if the probability distribution of the agents’ type profiles satisfies two conditions: the well-known condition of Crémer and McLean [1988. Full extraction of the surplus in Bayesian and dominant strategy auctions, Econometrica 56, 1247–1257] and the Identifiability condition introduced in this paper. We also show that these conditions are necessary for ex-post efficiency to be attainable with budget balance and individual rationality, and that the expected social surplus in these mechanisms can be distributed in any desirable way. Lastly, we demonstrate that, like Crémer–McLean condition, the Identifiability condition is generic if there are at least three agents.     

Cost Sharing under Increasing Returns: A Comparison of Simple Mechanisms

A technology with decreasing marginal costs is used by agents with equal rights. Each agent demands a quantity of output and costs are divided by means of a fixed formula. Several such mechanisms are compared for the existence of Nash equilibrium demand profiles and for the equity properties of these equilibria. Among three mechanisms, average cost pricing, the Shapley–Shubik cost sharing, and serial cost-sharing, only the latter two possess at least one Nash equilibrium on a reasonable domain of individual preferences. Only the serial cost sharing equilibria pass the equity tests of No Envy and Stand Alone cost.Journal of Economic LiteratureClassification Numbers: C72, D63.     

Market demand of smart but uninformed consumers rotates counterclockwise with better information: surprising welfare effects

Providing truthful and unbiased information about the true value of a good to a priori heterogeneous consumers generates a mean-preserving counterclockwise rotation of demand. The welfare analysis of such rotation in monopoly and perfectly competitive models indicates that consumers can lose surplus if they become better informed.     

Truthful mechanism design for multidimensional scheduling via cycle monotonicity

We consider the makespan-minimization problem on unrelated machines in the context of algorithmic mechanism design. No truthful mechanisms with non-trivial approximation guarantees are known for this multidimensional domain. We study a well-motivated special case (also a multidimensional domain), where the processing time of a job on each machine is either “low” or “high.” We give a general technique to convert any c-approximation algorithm (in a black-box fashion) to a 3c-approximation truthful-in-expectation mechanism. Our construction uses fractional truthful mechanisms as a building block, and builds upon a technique of Lavi and Swamy [Lavi, R., Swamy, C., 2005. Truthful and near-optimal mechanism design via linear programming. In: Proc. 46th FOCS, pp. 595–604]. When all jobs have identical low and high values, we devise a deterministic 2-approximation truthful mechanism. The chief novelty of our results is that we do not utilize explicit price definitions to prove truthfulness. Instead we design algorithms that satisfy cycle monotonicity [Rochet, J., 1987. A necessary and sufficient condition for rationalizability in a quasilinear context. J. Math. Econ. 16, 191–200], a necessary and sufficient condition for truthfulness in multidimensional settings; this is the first work that leverages this characterization.     

Trading with a common agent under complete information: A characterization of Nash equilibria

We analyze an abstract model of trading where N principals submit quantity-payment schedules that describe the contracts they offer to an agent, and the agent then chooses how much to trade with every principal. This represents a special class of common agency games with complete information. We study all the subgame perfect Nash equilibria of these games, not only truthful ones, providing a complete characterization of equilibrium payoffs. In particular, we show that the equilibrium that is Pareto-dominant for the principals is not truthful when there are more than two of them. We also provide a partial characterization of equilibrium strategies.     

Information and incentives in labor-managed economies

The incentive problems that result in labor-managed economies from attempting to eliminate the inefficient allocation of labor due to this institutional arrangement are discussed. Games are searched for such that, at an equilibrium, firms have revealed truthful information and labor is allocated efficiently. It is shown that such games do not exist if output is not observable, and even if aggregate deficits or surpluses are permitted. By contrast, if output is observable, balanced games exist in which it is dominant strategy for each firm to be truthful.     

Optimal collusion-resistant mechanisms with verification

We present the first general positive result on the construction of collusion-resistant mechanisms, that is, mechanisms that guarantee dominant strategies even when agents can form arbitrary coalitions and exchange compensations (sometimes referred to as transferable utilities or side payments). This is a much stronger solution concept as compared to truthful or even group strategyproof mechanisms, and only impossibility results were known for this type of mechanisms in the “classical” model.We describe collusion-resistant mechanisms with verification that return optimal solutions for a wide class of mechanism design problems (which includes utilitarian ones as a special case). Note that every collusion-resistant mechanism without verification must have an unbounded approximation factor and, in general, optimal solutions cannot be obtained even if we content ourselves with truthful (“non-collusion-resistant”) mechanisms. All these results apply to problems that have been extensively studied in the algorithmic mechanism design literature like, for instance, task scheduling and inter-domain routing.     

Bounding the inefficiency of equilibria in nonatomic congestion games

Equilibria in noncooperative games are typically inefficient, as illustrated by the Prisoner's Dilemma. In this paper, we quantify this inefficiency by comparing the payoffs of equilibria to the payoffs of a “best possible” outcome. We study a nonatomic version of the congestion games defined by Rosenthal [Int. J. Game Theory 2 (1973) 65], and identify games in which equilibria are approximately optimal in the sense that no other outcome achieves a significantly larger total payoff to the players—games in which optimization by individuals approximately optimizes the social good, in spite of the lack of coordination between players. Our results extend previous work on traffic routing games.     

A Characterization for Dominant Strategy Implementation

We introduce a perfect price discriminating mechanism for allocation problems with private information. A perfect price discriminating mechanism treats a seller, for example, as a perfect price discriminating monopolist who faces a price schedule that does not depend on her report. In any perfect price discriminating mechanism, every player has a dominant strategy to truthfully report her private information.We establish a characterization for dominant strategy implementation: Any outcome that can be dominant strategy implemented can also be dominant strategy implemented using a perfect price discriminating mechanism. We apply this characterization to derive the optimal, budget-balanced, dominant strategy mechanisms for public good provision and bilateral bargaining.     

House Allocation with Transfers

We consider the Shapley–Scarf house allocation problem where monetary transfers are allowed. We characterize the class of mechanisms that are strategy-proof, ex post individually rational, ex post budget-balanced, and “collusion-proof.” In these mechanisms, the price of each object is fixed in advance, and the objects are reallocated according to the (unique) core assignment of the Shapley–Scarf economy associated with the prices. The special case in which all prices are zero is the core mechanism studied by Shapley and Scarf. Our mechanisms are compelling alternatives to the Groves mechanisms, which satisfy neither budget balance nor our condition of collusion-proofness. Journal of Economic Literature Classification Numbers: C71, C78, D71, D78, D89.     

Profit sharing in unique Nash equilibrium: Characterization in the two-agent case

Two agents jointly operate a decreasing marginal returns technology to produce a private good. We characterize the class of output-sharing rules for which the labor-supply game has a unique Nash equilibrium. It consists of two families: rules of the serial type which protect a small user from the negative externality imposed by a large user, and rules of the reverse serial type, where one agent effectively employs the other agent's labor. Exactly two rules satisfy symmetry; a result in sharp contrast with Moulin and Shenker's characterization of their serial mechanism as the unique cost-sharing rule satisfying the same incentives property [Moulin, H., Shenker, S., 1992. Serial cost sharing. Econometrica 60 (5), 1009–1037]. We also show that the familiar stand-alone test characterizes the class of fixed-path methods under our incentives criterion [Friedman, E.J., 2004. Strong monotonicity in surplus sharing. Econ. Theory 23, 643–658].     

Stability by deterrence in cooperative non-sidepayment n-person games

This paper reports several experimental tests of the deterrence set, a solution concept for n-person games proposed by Laffond and Moulin (1977, 1981). This solution concept is distinctive because it specifies equilibria attained through the use of threats, where threats are conceptualized as costly not only to the target but also to the user. The laboratory tests were conducted in the context of 3- and 4-person cooperative non-sidepayment matrix games. In the first experimental test, the deterrence set was juxtaposed against the imputation set. Results indicate that the deterrence set has greater predictive accuracy than the imputation set. In a series of further tests, the deterrence set was juxtaposed against both the imputation set and the von Neumann-Morgenstern stable set solution. Results again show that the deterrence set is more accurate than the imputation set, but neither the deterrence set nor the stable set is reliably more accurate than the other. Overall, these results indicate that deterrence is a viable basis for stability in cooperative non-sidepayment games.     

Combinatorial Games under Auction Play

ARichman gameis a combinatorial game in which, rather than alternating moves, the two players bid for the privilege of making the next move. The theory of such games is a hybrid between the classical theory of games (von Neumann, Morgenstern, …) and the combinatorial theory of games (Berlekamp, Conway, Guy, …). We expand upon our previous work by considering games with infinitely many positions as well as several variants including thePoorman variantin which the high bidder pays a third party (rather than the other player).Journal of Economic LiteratureClassification Number: C7.     

Cooperation without Reputation: Experimental Evidence from Prisoner's Dilemma Games

This paper investigates cooperative play in prisoner's dilemma games by designing an experiment to evaluate the ability of two leading theories of observed cooperation: reputation building and altruism. We analyze both one-shot and finitely repeated games to gauge the importance of these theories. We conclude that neither altruism nor reputation building alone can explain our observations. The reputation model is inconsistent with play in both one-shots and finitely repeated games while the model with altruism is unable to explain observed play in the finitely repeated games.Journal of Economic LiteratureClassification Numbers: C72, C92.     

Investment Professionals' Ability to Detect Deception: Accuracy,Bias and Metacognitive Realism

In the first empirical study on the topic, the authors examined the ability of investment professionals to distinguish between truthful and deceptive statements. A random sample of 154 investment professionals made judgments about a series of truthful and deceptive statements, some of which involved financial fraud. Investment professionals' lie detection accuracy was poor; participants performed no better than would be expected by chance. Accuracy in identifying lies about financial fraud was especially poor. Further, participants displayed poor metacognitive realism when assessing their own performance. The theoretical and practical implications for lie detection in the financial industry are discussed.