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.     

On the genericity of full surplus extraction in mechanism design

Heifetz and Neeman [A. Heifetz, Z. Neeman, On the generic (im)possibility of full surplus extraction, Econometrica 74 (2006) 213-233], using convex combinations of models, showed that full surplus extraction (FSE) in mechanism design is generically impossible, contrary to the seminal work of Cremer and McLean [J. Cremer, R. McLean, Full extraction of the surplus in Bayesian and dominant strategy auctions, Econometrica 53 (1988) 345-361]. Since Cremer and McLean did not allow convex combinations of models, the two results are not comparable. We show that FSE is generically impossible when convex combinations of models are not allowed, provided that we do not hold fixed the cardinality of models.     

Truthful approximation mechanisms for restricted combinatorial auctions

When attempting to design a truthful mechanism for a computationally hard problem such as combinatorial auctions, one is faced with the problem that most efficiently computable heuristics can not be embedded in any truthful mechanism (e.g. VCG-like payment rules will not ensure truthfulness).We develop a set of techniques that allow constructing efficiently computable truthful mechanisms for combinatorial auctions in the special case where each bidder desires a specific known subset of items and only the valuation is unknown by the mechanism (the single parameter case). For this case we extend the work of Lehmann, O'Callaghan, and Shoham, who presented greedy heuristics. We show how to use If-Then-Else constructs, perform a partial search, and use the LP relaxation. We apply these techniques for several canonical types of combinatorial auctions, obtaining truthful mechanisms with provable approximation ratios.     

Optimal auctions with asymmetrically informed bidders

Summary. The paper analyzes a problem of optimal auction design when the seller faces asymmetrically informed bidders. Specifically, we consider a continuum of risk-neutral uninformed bidders taking part into the auction along with n risk-averse informed bidders. The contribution of the paper is threefold. First, we fully characterize the optimal auction in this non standard environment and in a very general set-up. We find that when informed bidders reveal “bad news” about the value of the good, the seller optimally awards the object to the uninformed bidders. Secondly, we show that the seller is better off in presence of uninformed bidders because this allows to lower the informational rents paid to the informed bidders. Last, we find that, with bi-lateral risk neutrality, the seller always awards the good to the uninformed bidders thereby keeping all the surplus.Received: 22 October 2004, Revised: 21 April 2005, JEL Classification Numbers: D44, D82.We are very grateful to two anonymous referees, Jacques Crémer, Patrick François, Angel Hernando-Veciana and seminar participants at the 2004 SCSE conference (Quebec, Canada) for their valuable comments. Moez Bennouri acknowledges the financial support by the Initiative of the New Economy (INE) program of SSHRC (Canada).     

Mechanism Design with Interdependent Valuations: Surplus Extraction

If valuations are interdependent and agents observe their own allocation payoffs, then two-stage revelation mechanisms expand the set of implementable decision functions. In a two-stage revelation mechanism agents report twice. In the first stage - before the allocation is decided - they report their private signals. In the second stage - after the allocation has been made, but before final transfers are decided - they report their payoffs from the allocation. Conditions are provided under which an uninformed seller can extract (or virtually extract) the full surplus from a sale to privately informed buyers, in spite of the buyers’ signals being independent random variables. This research was started when I was visiting the Department of Applied Mathematics of the University of Venice, and continued while visiting the European University Institute in Florence. Their financial support is gratefully acknowledged.     

On the emergence of non‐profit orchestras

In the market for live classical music, a symphony orchestra typically has fixed costs that are high relative to demand, so that the demand curve lies entirely below the average cost curve (Baumol & Bowen, 1966)—a situation in which a for‐profit enterprise cannot survive. The present study aims to explain how a non‐profit orchestra can survive in such an adverse market environment by relying on private donations, even in the absence of altruism. We argue that a financially distressed orchestra may employ a strategy to impose a non‐profit distribution constraint on itself—thus becoming a non‐profit, tax‐deductible organization—and use its member musicians' worker surplus to produce donor privileges, which enables the orchestra to induce donations from an individually rational audience by taking advantage of a tax deduction scheme. With this strategy, the orchestra can successfully extract consumer surplus from the audience to offset its loss.     

A characterization of efficient, bayesian incentive compatible mechanisms

Summary. A mechanism that is both efficient and incentive compatible in the Bayesian-Nash sense is shown to be payoff-equivalent to a Groves mechanism at the point in time when each agent has just acquired his private information. This equivalence result simplifies the question of whether or not an efficient, Bayesian incentive compatible mechanism can satisfy other desired objectives, for the search for an appropriate mechanism can be restricted to the family of Groves mechanisms. The method is used to extend the result of Myerson and Satterthwaite on the inefficiency of bilateral bargaining to a multilateral setting. Received: June 30, 1997; revised version: May 22, 1998     

A shaky business: Natural gas extraction,earthquakes and house prices

The production of natural gas is strongly increasing around the world. Long-run negative external effects of extraction are understudied and often ignored in (social) cost-benefit analyses. One important example is that natural gas extraction leads to soil subsidence and subsequent induced earthquakes that may occur only after a couple of decades. We show that induced earthquakes that are noticeable to residents generate substantial non-monetary economic effects, as measured by their effects on house prices, also when house owners are fully compensated for damage to their houses. To address the issue that earthquakes do not occur randomly over space, we use temporal variation in the occurrence of noticeable earthquakes while controlling for the occurrence of earthquakes that cannot be felt by house owners. We find that earthquakes that are noticeable with peak ground velocities of above half a cm/s lead to price decreases of 1.9 percent. The total non-monetary costs of induced earthquakes for Groningen are about €170 million (about €600 per household). These results indicate that the non-monetary costs are in the same order of magnitude as the monetary damage costs.