John O. Ledyard

Allocating uncertain and unresponsive resources: an experimental approach

We identify an important class of economic problems that arise naturally in several applications: the allocation of multiple resources when there are uncertainties in demand or supply, unresponsive supplies (no inventories and fixed capacities), and significant demand indivisibilities (rigidities). Examples of such problems include: scheduling job shops, airports, or supercomputers; zero-inventory planning; and the allocation and pricing of NASAs planned Space Station. Using experimental methods, we show that the two most common organizations used to deal with this problem, markets and administrative procedures, can perform at very low efficiencies (60-65% efficiency in a seemingly robust example). Thus, there is a need to design new mechanisms that more efficiently allocate resources in these environments. We develop and analyze two mechanisms that arise naturally from auctions used to allocate single-dimensional goods. These new mechanisms involve computer-assisted coordination made possible by the existence of networked computers. Both mechanisms significantly improve on the performance of administrative and market procedures.

The First Use of a Combined-Value Auction for Transportation Services

Combined-value auctions (CVAs) allow participants to make an offer of a single amount for a collection of items. These auctions provide value to both buyers and sellers of goods or services in a number of environments, but they have rarely been implemented, perhaps because of lack of knowledge and experience. Sears Logistics Services (SLS) is the first procurer of trucking services to use a CVA to reduce its costs. In 1993, it saved 13 percent over past procurement practices. Experimental economics played a crucial role in the development, sale, and use of the CVA.

The Promise of Prediction Markets

The ability of groups of people to make predictions is a potent research tool that should be freed of unnecessary government restrictions.

Mutually Destructive Bidding: The FCC Auction Design Problem

In general, synergies across license valuations complicate the auction design process. Theory suggests that a “simple” (i.e., non-combinatorial) auction will have difficulty in assigning licenses efficiently in such an environment. This difficulty increases with increases in “fitting complexity.” In some environments, bidding may become “mutually destructive.” Experiments indicate that a properly designed combinatorial auction is superior to a simple auction in terms of economic efficiency and revenue generation in bidding environments with a low amount of fitting complexity. Concerns that a combinatorial auction will cause a “threshold” problem are not borne out when bidders for small packages can communicate.

Designing organizations for trading pollution rights

Regulators and academicians have recently become interested in using a marketable permits program as a new way to control aggregate pollution emissions. Our research focuses on choosing a permit trading mechanism that is both economically efficient and politically viable. We consider an organized trading process and a revenue neutral auction, both of which involve an initial allocation of permits based on past history. Each is tested in a competitive and in a non-competitive environment to determine which mechanism performs best. The results of our research suggest that, overall, the organized trading process outperforms the revenue neutral auction.

A Theory of Electoral Equilibrium: A Spatial Analysis Based on the Theory of Games

Two areas of political science that utilize rigorous deductive formulations are: (1) the paradox of voting, and (2) spatial analysis of election competition. It is not surprising that the analysis of the paradox and the development of spatial theory occur simultaneously because the concerns of both endeavors are parallel: we study the paradox to ascertain conditions under which majority-rule equilibria exist, that is, conditions under which at least one alternative exists that cannot be

Incentive compatibility and incomplete information

It is by now reasonably well known that when informationally decentralized processes are used to make collective choice decisions or to allocate resources, individuals may find it in their interest to distort the information they provide and that these distortions may lead to non-optimal group decisions. In the social choice context, this has been formalized in the Gibbard-Satterthwaite Theorem, which states that all non-dictatorial rules will have this property. In a different context, Hurwicz has shown that there is a private goods neo-classical exchange economy such that any decentralized mechanism which selects Pareto-optimal allocations and which has a no-trade option will have this property. Roberts has provided a similar example in the public goods context. Other work (e.g., Green-Laffont, Groves-Loeb, Hurwicz, and Walker) indicates that, for mechanisms designed to select efficient outcomes, in most environments some agent will have an incentive to misrepresent his information and thus to manipulate the mechanism. All these results lead one to the conjecture that it is almost impossible to design any mechanism for group decisions which is compatible with individual incentives and efficiency.

The scope of the hypothesis of Bayesian equilibrium

What behavior can be explained as the Bayes equilibrium of some game? The main finding is almost anything. Given any Bayesian (coordination) game with positive priors and given any vector of nondominated strategies, there is an increasing transformation of each utility function such that the given vector of strategies is a Bayes (Nash) equilibrium of the transformed game. Any nondominated behavior can be rationalized as Bayes equilibrium behavior. Some comments on the implications of these results for game theory are included.

A Characterization of Interim Efficiency with Public Goods

In this paper, we consider the following classical public goods problem. A group of individuals must decide on a level of public good that is produced according to constant returns to scale up to some capacity constraint. In addition to deciding the level of public good, the group must decide how to tax the individuals in the group in order to cover the cost. The distribution of the burden of taxation is important because different individuals have different marginal rates of substitution between the private good (taxes) and the public good, and may have different incomes as well. These individual marginal rates of substitution are private information; that is, each individual knows his or her own marginal rate of substitution, but not those of the other members of the group. Adopting a Bayesian mechanism design framework, we assume that the distribution of marginal rates of substitution is common knowledge.

The approximation of efficient public good mechanisms by simple voting schemes

This paper compares the performance of simple voting rules, called referenda, to the performance of interim efficient mechanisms for the provision of a public good. In a referendum, voters simply vote for or against the provision of the public good, and production of the public good depends on whether or not the number of yes votes exceeds a prespecified threshold. Costs are shared equally. We show that in large populations for any interim efficient allocation rule, there exists a corresponding referendum that yields approximately the same total welfare when there are many individuals. Moreover, if there is a common value component to the voters’ preferences, then there is a unique approximating referendum.