On etudie des regles de decision collective stochastique qui, pour chaque ensemble realisable d'alternatives et pour chaque profil de classements individuels, specifient des probabilites de decision collective pour les alternatives realisables
For many years, social scientists have been interested in obtaining testable definitions of causality (Granger 1969, Sims 1972). Recent works include those of Chamberlain (1982) and Florens and Mouchart (1982). The present paper first clarifies the results of these latter papers by considering a unifying definition of noncausality. Then, log-likelihood ratio (LR) tests for noncausality are derived for qualitative panel data under the minimal assumption that one series is Markov. LR tests for the Markov property are also obtained. Both test statistics have closed forms. These tests thus provide a readily applicable procedure for testing noncausality on qualitative panel data. Finally, the tests are applied to French Business Survey data in order to test the hypothesis that price changes from period to period are strictly exogenous to disequilibria appearing within periods.
This paper investigates the effect that common knowledge of public information has on individual beliefs. We assume that n individuals start with the same prior beliefs over a finite probability space, and then each observes private information. We prove that if an admissible statistic of their posterior probabilities of an event becomes common knowledge, then everyone's posterior probabilities for that event must be the same. The class of admissible statistics includes any statistic which is an invertible function of a stochastically monotone function. We also prove that if information partitions are finite, an iterative procedure of public announcement of the statistic-where the statistic is publicly announced and then individuals recompute posterior probabilities based on their previous information plus the announced value of the statistic-converges in a finite number of steps to the common knowledge situation described above. The result has applications to asymmetric information models in economics, where private information becomes incorporated into an aggregate, publicly observed statistic such as a price or quantity in a market.
The model analyzed here constrains most work on the main job to be full time. Partial retirement requires a job change and a wage reduction.Estimates of utility function parameters and their distributions incorporate information on age of leaving the main job and of full retirement. These estimates determine the slope at different ages and the convexity of within period indifference curves between compensation and leisure. Even though age specific dummy variables are not used, the model closely tracks retirement behavior. Policy analysis based on earlier models with simpler structures is shown to be misleading.
[This paper establishes a simple existence result for solutions to variational problems of the form ∫_0^∞ G(x, ẋ, t) dt or ∫_0^∞ G(x, ẋ, ẍ, t) dt. The key assumptions are that G have an integrable upper bound, that it satisfy a growth condition, and that it be concave as a function of the highest order derivative in the problem, other arguments held constant. The discussion illustrates why three well known types of problems fail to have solutions. For two of these—chattering and cake eating—extended solution concepts are contrasted with simple modifications that restore the existence of a conventional solution. In a third case—state variables with jumps—the source of the difficulty is fundamental. For these problems a natural extended solution, analogous to the extension from probability density functions to general distribution functions, is suggested.]
The Nash equilibrium concept may be extended gradually when the rules of the game are interpreted in a wider and wider sense, so as to allow preplay or even intraplay communication. A well-known extension of the Nash equilibrium is Aumann's correlated equilibrium, which depends only on the normal form of the game. Two other solution concepts for multistage games are proposed here: the extensive form correlated equilibrium, where the players can observe private extraneous signals at every stage and the communication equilibrium, where the players are furthermore allowed to transmit inputs to an appropriate device at every stage. We show that the set of payoffs associated with each solution concept has a canonical representation (in the spirit of the revelation principle) and is a convex polyhedron. We also provide for each concept a super-canonical game such that the set of payoffs associated with the solution concept is precisely the set of Nash equilibrium payoffs of this game.