nep-gth New Economics Papers
on Game Theory
Issue of 2007‒05‒12
ten papers chosen by
Laszlo A. Koczy
University of Maastricht

  1. Five Indefinitely Repeated Games in the Laboratory By Jim Engle-Warnick
  2. A characterization and some properties of the Banzhaf-Coleman-Dubey-Shapley sensitivity index By Barua, Rana; Chakravarty, Satya R.; Roy, Sonali; Sarka, Palash
  3. Measuring Power in Weighted Majority Games By Barua, Rana; Chakravarty, Satya R.; Roy, Sonali
  5. Are Imitative Strategies Game Specific? Experimental Evidence from Market Games By Niall O'Higgins; Patrizia Sbriglia
  6. A new characterization of the Banzhaf index of power By Barua, Rana; Chakravarty, Satya R.; Roy, Sonali
  7. On the Coleman indices of voting power By Barua, Rana; Chakravarty, Satya R.; Roy, Sonali
  8. Bilateral Matching and Bargaining with Private Information By Wong, Adam Chi Leung; Shneyerov, Art
  9. The Rate of Convergence to Perfect Competition of a Simple Matching and Bargaining Mechanism By Shneyerov, Art; Wong, Adam Chi Leung
  10. Droft and Equilibrium Selection with Human and Computer Players By Mauro Caminati; Alessandro Innocenti; Roberto Ricciuti

  1. By: Jim Engle-Warnick
    Abstract: I experimentally test play in five indefinitely repeated games: a hawk-dove game, a game of chicken, a trust game, a coordination game, and a constant-sum game. I compare the different game histories that affect decision making in each of the games. <P>Une étude expérimentale a été menée afin de tester les décisions prises lors de cinq jeux répétés où le nombre de répétitions est inconnu : un jeu de type hawk-dove, un jeu de type chicken, un jeu de confiance, un jeu de coordination et un jeu à somme constante. Les historiques des différents jeux sont comparés afin d’analyser les prises de décisions des participants dans chaque jeu.
    Keywords: experimental economics, repeated games, économie expérimentale, jeux répétés
    Date: 2007–05–01
  2. By: Barua, Rana; Chakravarty, Satya R.; Roy, Sonali; Sarka, Palash
    Abstract: A sensitivity index quantifies the degree of smoothness with which it responds to fluctuations in the wishes of the members of a voting body. This paper characterizes the Banzhaf–Coleman–Dubey–Shapley sensitivity index using a set of independent axioms. Bounds on the index for a very general class of games are also derived.
    Keywords: Voting game; The Banzhaf–Coleman–Dubey–Shapley sensitivity index; Characterization; Bounds
    Date: 2007–05–07
  3. By: Barua, Rana; Chakravarty, Satya R.; Roy, Sonali
    Abstract: This paper suggests an indicator of power in weighted majority games. An indicator of power determines the ability of a voter to influence the outcomes of the voting bodies he belongs to. In a weighted majority game each voter is assigned a certain nonnegative real number weight and there is a positive real number quota such that a group of voters can pass a resolution if the sum of the weights of the group members is at least as high as the given quota. The new index is shown to satisfy all the reasonable postulates for an index of voting power. If attention is restricted to weighted majority game only, then this index may be considered as an extension of the Banzhaf-Coleman power indices. Finally, the paper develops an axiomatic char­acterization of the new index.
    Date: 2007–05–07
  4. By: Jan Libich; Petr Stehlik
    Abstract: This paper proposes a simple framework that generalizes the timing structure of macroeconomic (as well as other) games. Building on alternative move games and models of "rational inattention" the players' actions may be rigid, ie optimally chosen to be infrequent. This rigidity makes the game more dynamic/asynchronous and by linking successive periods it can serve as commitment. Therefore, it can enhance cooperation and often eliminate inefficient equilibrium outcomes. We apply the framework to the Kydland-Prescott-Barro-Gordon monetraty policy game and dervice the conditions - the sufficient degree of commitment - under which the influential time-inconsistency problem disappears. Interestingly, (i) this can happen even in a finite game (possibly as short as two periods), (ii) the required degree of commitment may be rather (even infinitesimally) low and (iii) the policymaker's commitment may substitute for his conservatism and/or patience in achieving credibility. The analysis makes several predictions about explicit inflation targeting and central bank dependence (and their relationship) that we show to be empirically supported. In doing so we show that our theoretical results reconcile some conflicting empirical findings of the literature.
    JEL: C70 C72 E42 E61
    Date: 2007–04
  5. By: Niall O'Higgins; Patrizia Sbriglia
    Abstract: This paper studies imitation in price and quantity markets. We analyse the results of two experiments designed with different information settings. The analysis shows that information is used differently and has diverse effects according to the market under investigation.
    Keywords: Cournot, Bertrand experiments, imitation
    JEL: C91 D83
    Date: 2006–10
  6. By: Barua, Rana; Chakravarty, Satya R.; Roy, Sonali
    Abstract: This paper develops a new axiomatic characterization of the Banzhaf index of power using four axioms from four different contributions to the area. A nice feature of the characterization is independence of the axioms showing importance of each of them in the exercise.
    Keywords: Voting game; voting power; Banzhaf index; axioms; characterization
    Date: 2007–05–07
  7. By: Barua, Rana; Chakravarty, Satya R.; Roy, Sonali
    Abstract: Coleman [1971. Control of collectives and the power of a collectivity to act. In: Lieberman, B. (Ed.), Social Choice. Gordon and Breach, New York, pp. 269–298] suggested two indices of voting power, power to prevent an action and power to initiate an action. This paper rigorously demonstrates relationship between the two indices and shows that they satisfy several attractive properties.
    Keywords: Game theory; Voting game; Voting power; Coleman’s indices; Properties
    Date: 2007–05–07
  8. By: Wong, Adam Chi Leung; Shneyerov, Art
    Abstract: We explore the role of private information in bilateral matching and bargaining. Our model is a replica of Mortensen and Wright (2002), but with private information. A simple necessary and sufficient condition on the parameters of the model for existence of equilibrium with entry is obtained. As in Mortensen and Wright (2002), we find that equilibrium is unique and has the property that every meeting results in trade when the discount rate is sufficiently small. There are also equilibria in which not every meeting results in trade. All equilibria converge to perfect competition as the frictions of search costs and discounting are removed. We find that private information may deter entry. Because of matching externalities, this entry-deterring effect of private information may be welfare-enhancing.
    JEL: C73 C78 D83
    Date: 2007–05–01
  9. By: Shneyerov, Art; Wong, Adam Chi Leung
    Abstract: We study the steady-state of a market with inflowing cohorts of buyers and sellers who are randomly matched pairwise and bargain under private information. Two bargaining protocols are considered: take-it-or-leave-it offering and the double auction. There are frictions due to costly search and time discounting, parameterized by a single number t > 0 proportional to the waiting time until the next meeting. We study the efficiency of these mechanisms as the frictions are removed, i.e. t 0. We find that all equilibria of the take-it-or-leave-it offering mechanism converge to the Walrasian limit, at the fastest possible rate O(t) among all bargaining mechanisms. For the double auction mechanism, we find that there are equilibria that converge at the linear rate, those that converge at a slower rate or even not converge at all.
    JEL: C73 C78 D83
    Date: 2007–05–01
  10. By: Mauro Caminati; Alessandro Innocenti; Roberto Ricciuti
    Abstract: The theory of drift (Binmore and Samuelson 1999) concerns equilibrium selection in which second order disturbances may have first-order effects in the emergence of one equilibrium over the other. We provided experimental evidence with human players supporting the model in Caminati, Innocenti and Ricciuti (2006). In this paper we test it with conditioning by computer players. When computers are removed and humans are matched against each other, the comparative static properties of the model are confirmed.
    Keywords: drift, equilibrium selection, evolutionary games, experiments.
    JEL: C72 C92
    Date: 2007–04

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