nep-gth New Economics Papers
on Game Theory
Issue of 2006‒12‒09
seven papers chosen by
Laszlo A. Koczy
Universiteit Maastricht

  1. The Geometry of Nash Equilibria and Correlated Equilibria and a Generalization of Zero-Sum Games By Viossat, Yannick
  2. Efficiency, communication and honesty By Demichelis, Stefano; Weibull, Jörgen
  3. Stochastic Dynamics for the Matching Pennies Game By Ziv Gorodeisky
  4. Flippable Pairs and Subset Comparisons in Comparative Probability Orderings and Related Simple Games By CHRISTIAN, Robin; CONDER, Marston; SLINKO, Arkadii
  5. New Measure of Voting Power By František Turnovec
  6. A Note on Fairness, Power, Property, and Behind the Veil By Martin Shubik
  7. Sharing a River among Satiable Countries By AMBEC, Steve; EHLERS, Lars

  1. By: Viossat, Yannick (Dept. of Economics, Stockholm School of Economics)
    Abstract: A pure strategy is coherent if it is played with positive probability in at least one correlated equilibrium. A game is pre-tight if in every correlated equilibrium, all incentives constraints for non deviating to a coherent strategy are tight. We show that there exists a Nash equilibrium in the relative interior of the correlated equilibrium polytope if and only if the game is pre-tight. Furthermore, the class of pre-tight games is shown to include and generalize the class of two-player zero-sum games.
    Keywords: correlated equilibrium; Nash equilibrium; zero-sum games; dual reduction
    JEL: C72
    Date: 2006–08–29
  2. By: Demichelis, Stefano (Università degli studi di Pavia); Weibull, Jörgen (Dept. of Economics, Stockholm School of Economics)
    Abstract: We here develop a model of pre-play communication that generalizes the cheap-talk approach by allowing players to have a lexicographic preference, second to the payoffs in the underlying game, for honesty. We formalize this by way of an honesty (or truth) correspondence between actions and statements, and postulate two axioms met by natural languages. The model is applied to finite and symmetric two-player games and we establish that honest communication and play of the Pareto dominant Nash equilibrium together characterize the unique evolutionarily stable set in generic and symmetric n×n-coordination games. In particular, this holds even in Aumann's (1990) example of a Pareto dominant equilibrium that is not self-enforcing.
    Keywords: efficiency; communication; coordination; honesty; evolutionary stability
    JEL: C72 C73 D01
    Date: 2006–02–01
  3. By: Ziv Gorodeisky
    Date: 2006–12–03
  4. By: CHRISTIAN, Robin; CONDER, Marston; SLINKO, Arkadii
    Abstract: We show that every additively representable comparative probability order on n atoms is determined by at least n - 1 binary subset comparisons. We show that there are many orders of this kind, not just the lexicographic order. These results provide answers to two questions of Fishburn et al (2002). We also study the flip relation on the class of all comparative probability orders introduced by Maclagan. We generalise an important theorem of Fishburn, Peke?c and Reeds, by showing that in any minimal set of comparisons that determine a comparative probability order, all comparisons are flippable. By calculating the characteristics of the flip relation for n = 6 we discover that the regions in the corresponding hyperplane arrangement can have no more than 13 faces and that there are 20 regions with 13 faces. All the neighbours of the 20 comparative probability orders which correspond to those regions are representable. Finally we define a class of simple games with complete desirability relation for which its strong desirability relation is acyclic, and show that the flip relation carries all the information about these games. We show that for n = 6 these games are weighted majority games.
    Keywords: Additively reesentable linear orders, comrative obability, elicitation, subset comrisons, sime game, weighted majority game, desirability relation.
    Date: 2006
  5. By: František Turnovec (Institute of Economic Studies, Faculty of Social Sciences, Charles University, Prague, Czech Republic)
    Abstract: During last two decades we observe a boom of power indices literature related to constitutional analysis of European Union institutions and distribution of intrainstitutional and inter-institutional influence in the European Union decision making. Growing interest to power indices methodology leads also to reconsideration of the methodology itself. In this paper a new general a priori voting power measure is proposed distinguishing between absolute and relative power. This power measure covers traditional Shapley-Shubik and Penrose-Banzhaf power indices as its special cases.
    Keywords: Absolute power; cooperative games; decisive situation; I-power; pivot; power indices; P-power; relative power; swing
    JEL: D71 D74
    Date: 2005
  6. By: Martin Shubik (Cowles Foundation, Yale University)
    Abstract: An Axiomatization for Power and for Equity differ only in the addition of a Behind the Veil Axiom.
    Keywords: Value, Behind the veil, Power, Equity, Ownership
    JEL: C71 D63
    Date: 2006–11
  7. By: AMBEC, Steve; EHLERS, Lars
    Abstract: With diminishing global water reserves the problem of water allocation becomes increasingly important. We consider the problem of efficiently sharing a river among a group of satiable countries. Inducing countries to efficiently cooperate requires monetary compensations via international agreements. We show that cooperation of the other countries exerts a positive externality on the benefit of a coalition. Our problem is to distribute the benefit of efficiently sharing the river under these constraints. If the countries outside of a coalition do not cooperate at all, then the downstream incremental distribution is the unique compromise between the absolute territorial sovereignty (ATS) doctrine and the unlimited territorial integrity (UTI) doctrine. If all countries outside of a coalition cooperate, then there may not exist any distribution satisfying the UTI doctrine.
    Keywords: Water Allocation, Externalities
    JEL: C71 D62 H23
    Date: 2006

This nep-gth issue is ©2006 by Laszlo A. Koczy. It is provided as is without any express or implied warranty. It may be freely redistributed in whole or in part for any purpose. If distributed in part, please include this notice.
General information on the NEP project can be found at For comments please write to the director of NEP, Marco Novarese at <>. Put “NEP” in the subject, otherwise your mail may be rejected.
NEP’s infrastructure is sponsored by the School of Economics and Finance of Massey University in New Zealand.