25,555 research outputs found
Partially-honest Nash implementation: Characterization results
No full textThis paper studies implementation problems in the wake of a recent trend of implementation of non-consequentialist nature, which draws on the evidence taken from experimental and behavioral economics. Specifically, following the seminal works by Matsushima (2008) and Dutta and Sen (2009), the paper considers implementation problems with partially-honest agents, which presume that there is at least one individual in society who concerns herself with not only outcomes but also honest behavior at least in a limited manner. Given this setting, the paper provides a general characterization of Nash implementation with partially-honest individuals. It also provides the necessary and sufficient condition for Nash implementation with partially-honest individuals by mechanisms with some types of strategy-space reductions. As a consequence, it shows that in contrast to the case of the standard framework, the equivalence between Nash implementation and Nash implementation with strategy space reduction no longer holds.Nash implementation, canonical-mechanisms, s-mechanisms, self-relevant mechanisms, partial-honesty, permissive results
Including Social Nash Equilibria in Abstract Economies
No full textWe consider quasi-variational problems (variational problems having constraint sets depending on their own solutions) which appear in concrete economic models such as social and economic networks, financial derivative models, transportation network congestion and traffic equilibrium. First, using an extension of the classical Minty lemma, we show that new upper stability results can be obtained for parametric quasi-variational and linearized quasi-variational problems, while lower stability, which plays a fundamental role in the investigation of hierarchical problems, cannot be achieved in general, even on very restrictive conditions. Then, regularized problems are considered allowing to introduce approximate solutions for the above problems and to investigate their lower and upper stability properties. We stress that the class of quasi-variational problems include social Nash equilibrium problems in abstract economies, so results about approximate Nash equilibria can be easily deduced.quasi-variational, social Nash equilibria, approximate solution, closed map, lower semicontinuous map, upper stability, lower stability
Correlated Nash Equilibrium
No full textNash equilibrium presumes that players have expected utility preferences, and therefore the beliefs of each player are represented by a probability measure. Motivated by Ellsberg-type behavior, which contradicts the probabilistic representation of beliefs, we generalize Nash equilibrium in n-player strategic games to allow for preferences conforming to the maxmin expected utility model of Gilboa and Schmeidler [Journal of Mathematical Economics, 18 (1989), 141–153]. With no strings attached, our equilibrium concept can be characterized by the suitably modified epistemic conditions for Nash equilibrium.Agreeing to disagree, Correlated equilibrium, Epistemic conditions, Knightian uncertainty, Multiple priors, Nash equilibrium
T Nash
No full textBorn and raised in Lynn, T Nash grew up in East Lynn on Alley Street and then later in West Lynn. A 1992 graduate of Lynn Technical High School and 1995 graduate of North Shore Community College, Nash has spent a life in childcare, education, nursing, and elder care. He is a member of North Shore Pride and Chairperson for the Lynn Pride Flag Raising. He is the proud parent of an adult daughter and five-year-old son, who she and her partner are raising in Salem. A self-described “bully” as a teen, Nash explains how violence and alcoholism shaped her childhood. T discusses the long process of growing comfortable with his sexual and gender identity as a lesbian and trans-man. T speaks fondly about Fran’s Place and enthusiastically about the victory of marriage equality. T is the author of a book about caregiving called "Try Kindness.
Canaday with UT President Nash
No full textFrom left: Ward M. Canaday, President Philip C. Nash, Loverett (Dover, Mass.)
Computing Good Nash Equilibria in Graphical Games
No full textThis paper addresses the problem of fair equilibrium selection in graphical games. Our approach is based on the data structure called the {\em best response policy}, which was proposed by Kearns et al.~\cite{kls} as a way to represent all Nash equilibria of a graphical game. In~\cite{egg}, it was shown that the best response policy has polynomial size as long as the underlying graph is a path. In this paper, we show that if the underlying graph is a bounded-degree tree and the best response policy has polynomial size then there is an efficient algorithm which constructs a Nash equilibrium that guarantees certain payoffs to all participants. Another attractive solution concept is a Nash equilibrium that maximizes the social welfare. We show that, while exactly computing the latter is infeasible (we prove that solving this problem may involve algebraic numbers of an arbitrarily high degree), there exists an FPTAS for finding such an equilibrium as long as the best response policy has polynomial size. These two algorithms can be combined to produce Nash equilibria that satisfy various fairness criteria
A Full Characterization of Nash Implementation with Strategy Space Reduction
No full textNoting that a full characterization of Nash-implementation is given using a canonical-mechanism and Maskin’s theorem (Maskin, 1999) is shown using a mechanism with Saijo’s type of strategy space reduction (Saijo, 1988), this paper fully characterizes the class of Nashimplementable social choice correspondences (SCCs) by mechanisms endowed with Saijo’s message space specification - s-mechanisms. This class of SCCs is further shown to be equivalent to the class of Nashimplementable SCCs, though any further ‘strategy space reduction’ mechanism breaks this equivalent relationship down.Nash implementation, strategy space reduction, s-mechanisms, Condition μsr, Condition Ms
Nash bargained consumption decisions: a revealed preference analysis.
No full textWe present a revealed preference analysis of the testable implications of the Nash bargaining solution. Our specific focus is on a two-player game involving consumption decisions. We consider a setting in which the empirical analyst has information on both the threat points bundles and the bargaining outcomes. We first establish a revealed preference characterization of the Nash bargaining solution. This characterization implies conditions that are both necessary and sufficient for consistency of observed consumption behavior with the Nash bargaining model. However, these conditions turn out to be nonlinear in unknowns and therefore difficult to verify. Given this, we subsequently present necessary conditions and sufficient conditions that are linear (and thus easily testable). We illustrate the practical usefulness of these conditions by means of an application to experimental data. Such an experimental setting implies a most powerful analysis of the empirical goodness of the Nash bargaining model for describing consumption decisions. To our knowledge, this provides a first empirical test of the Nash bargaining model on consumption data. Finally, we consider the possibility that threat point bundles are not observed. This obtains testable conditions for the Nash bargaining model that can be used in non-experimental (e.g. household consumption) settings, which often do not contain information on individual consumption bundles in threat points.
Fairness, Efficiency, and the Nash Bargaining Solution
No full textA bargaining solution balances fairness and efficiency if each player's payoff lies between the minimum and maximum of the payoffs assigned to him by the egalitarian and utilitarian solutions. In the 2-person bargaining problem, the Nash solution is the unique scale-invariant solution satisfying this property. Additionally, a similar result, relating the weighted egalitarian and utilitarian solutions to a weighted Nash solution, is obtained. These results are related to a theorem of Shapley, which I generalize. For n>=3, there does not exist any n-person scale-invariant bargaining solution that balances fairness and efficiency.Bargaining; fairness; efficiency; Nash solution
More strategies, more Nash equilibria
No full textThis short paper isolates a non-trivial class of games for which there exists a monotone relation between the size of pure strategy spaces and the number of pure Nash equilibria (Theorem). This class is that of two- player nice games, i.e., games with compact real intervals as strategy spaces and continuous and strictly quasi-concave payoff functions, assumptions met by many economic models. We then show that the sufficient conditions for Theorem to hold are tight.Strategic-form games, strategy spaces, Nash equilibrium, two players
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