Properties of Dual Reduction

Nous étudions les propriétés de la réduction duale : une technique de réduction des jeux finis qui permet d'opérer une sélection entre les équilibres corrélés. Nous montrons que le processus de réduction est indépendant des fonctions d'utilités choisies pour représenter les préférences des agents et que les jeux à deux joueurs ont génériquement une unique réduction duale pleine. De plus, dans une réduction duale pleine, toutes les stratégies et tous les profils de stratégie qui ne sont jamais jouées dans des équilibres corrélés sont éliminées. Nous étudions les propriétés supplémentaires qu'a la réduction duale dans plusieurs classes de jeux et nous comparons la réduction duale à d'autres concepts de raffinement des équilibre corrélés. Enfin, nous passons en revue et relions les différentes preuves d'existence des équilibres corrélés fondées sur la programmation linéaire.Réduction duale;Equilibres corrélés;Raffinement

An Information Economic Rationale for Cooperatives

We consider how to organize the processing and marketing of an agricultural product when farming costs are known only by the individual farmers. We show that when marginal costs are un-correlated, the market for …nal goods is competitive, and the market for processing is non-competitive, the socially optimal production levels are sustained by a cooperative and a cooperative only. We show also that the cooperative form is particularly useful when the cost uncertainty is large and the net average revenue product is small.economics of cooperatives, asymmetric information, incentives, rationing, Agribusiness,

Provision of club goods: cost sharing and selection of a provider

This paper characterizes optimal mechanisms facilitating the cost sharing and the selection of a provider for a club good. These mechanisms are allocatively and Pareto efficient. However, it appears that transfers occur even when the good is not provided. This result is due to the weakening of the incentive notion to Bayesian-Nash equilibrium and to the balanced budget condition. This phenomena disappears if the setting is perfectly symmetric.

Fairness in education: The Italian university before and after the reform

In 2001 the Italian tertiary education system embarked in a broad process of reform. The main novelty brought by the reform was a reduction of the length of study to get a first level degree together with the introduction of a 2-years, second level, master degree. This paper aims at studying the effects of the reform in terms of fairness in educational opportunity. In order to do so we first define fairness criteria following a well-developed responsibility sensitive egalitarian literature, we then discuss existing inequality of opportunity measures consistent with these criteria, we show their relationship, and we adapt them to the educational framework. We finally employ this set of measures to show the evolution of fairness in the access to university in Italy before and after the reform.Equality of opportunity, higher education.

Speculation in Standard Auctions with Resale

We analyze the role resale creates for zero-value bidders, called speculators, in standard auctions with symmetric independent private values buyers. English/second-price auctions always have equilibria with active resale markets and positive profits for a speculator. In first- price/Dutch auctions, the unique equilibrium can involve an active resale market, but is never profitable for a speculator. In all standard auctions, allowing resale can increase the initial seller's revenue and lead to an inefficient allocation. First-price and second-price auctions are not revenue equivalent.first-price, second-price, English, Dutch auctions, speculation, resale, efficiency

Nonlinear sequential designs for logistic item response theory models with applications to computerized adaptive tests

Computerized adaptive testing is becoming increasingly popular due to advancement of modern computer technology. It differs from the conventional standardized testing in that the selection of test items is tailored to individual examinee's ability level. Arising from this selection strategy is a nonlinear sequential design problem. We study, in this paper, the sequential design problem in the context of the logistic item response theory models. We show that the adaptive design obtained by maximizing the item information leads to a consistent and asymptotically normal ability estimator in the case of the Rasch model. Modifications to the maximum information approach are proposed for the two- and three-parameter logistic models. Similar asymptotic properties are established for the modified designs and the resulting estimator. Examples are also given in the case of the two-parameter logistic model to show that without such modifications, the maximum likelihood estimator of the ability parameter may not be consistent.Comment: Published in at http://dx.doi.org/10.1214/08-AOS614 the Annals of Statistics (http://www.imstat.org/aos/) by the Institute of Mathematical Statistics (http://www.imstat.org