nep-evo New Economics Papers
on Evolutionary Economics
Issue of 2006‒03‒18
five papers chosen by
Matthew Baker
US Naval Academy, USA

  1. Dynamically Stable Sets in Infinite Strategy Spaces By Thomas Norman
  2. The Impact of Group Membership on Cooperation and Norm Enforcement: Evidence using Random Assignment to Real Social Groups By Lorenz Goette; David Huffman; Stephan Meier
  3. Learning in Bayesian Games with Binary Actions By Alan Beggs
  4. The Evolution of Collective Action By David P. Myatt; Chris Wallace
  5. Cooperation through Imitation By James Bergin; Dan Bernhardt

  1. By: Thomas Norman
    Abstract: Evolutionary game theory has largely focused on finite games. Dynamic stability is harder to attain in infinite strategy spaces; Bomze (Monatshefte fur Mathematik 110, 1990, 189-206) and Oechssler and Riedel (Economic Theory 17, 2001, 141-162) provide conditions for the stability of rest points under the replicator dynamics. Here, conditions are given for the stability of sets of strategies under this process.
    Keywords: Replicator dynamics, Evolutionary stability, Continouus strategy spaces, Stable sets
    JEL: C70 C72
    Date: 2005
  2. By: Lorenz Goette (University of Zurich, CEPR and IZA Bonn); David Huffman (IZA Bonn); Stephan Meier (Federal Reserve Bank of Boston)
    Abstract: Due to incomplete contracts, efficiency of an organization depends on willingness of individuals to take non-selfish actions, e.g., cooperate when there is no incentive to do so, or punish inefficient actions by others. Organizations also constitute a social boundary, or group. We investigate whether this social aspect of organizations has an important benefit, fostering unselfish cooperation and norm enforcement within the group, but whether there is also a dark side, in the form of hostility between groups. Our experiment provides the first evidence without the confounding effect of self-selection into groups. Individuals are randomly assigned to different platoons during a four-week portion of officer training in the Swiss Army. We conduct choice experiments - simultaneous prisoner’s dilemma games, with and without third-party punishment - in week three. Random assignment significantly increases willingness to cooperate with fellow platoon members. Assignment does not lead to hostility, in the sense of vindictive punishment of outsiders, but does affect norm enforcement, enhancing willingness to enforce a norm of cooperation towards fellow platoon members. This suggests that the social aspect of organizations motivates efficient behavior even when ordinary incentives fail, and helps explain practices designed to foster social ties or group identification within an organization.
    Keywords: organizations, in-group favoritism, social identity, punishment
    JEL: D23 J00
    Date: 2006–03
  3. By: Alan Beggs
    Abstract: This paper considers a simple adaptive learning rule in Bayesian games where players employ threshold strategies. Global convergence results are given for supermodular games and potentital games.
    Keywords: Bayesian Games, Learning, Binary Actions, Passive Stochastic Approximation
    JEL: C72 D83
    Date: 2005
  4. By: David P. Myatt; Chris Wallace
    Abstract: A public good is produced if and only if a team of m or more volunteers contribute to it. An equilibrium-selection problem leads to the questions: will collective action succeed? If so, who will participate in the team? The paper studies the evolution of collective action: as part of a strategy-revision process, updating players choose quantal responses to existing play. With symmetric players, success depends upon the cost of contribution, the benefit from provision, and the critical team-size m; the relative variability of costs and benefits, and their correlation, are also critical. When players differ, successful teams consist of either the most efficient contributors, or those with the most idiosyncratic preferences. The addition of a single "bad apple" (for instance, an individual whose costs are particularly variable) to a population in which a successful team operates may result in destabilisation: over time, the bad apple might supplant an existing contributor, prompting a collapse.
    Keywords: Collective Action, Evolution, Teams, Equilibrium Selection, Exponential Cost, Rooted Trees.
    JEL: C72 C73 H41
    Date: 2005
  5. By: James Bergin (Queen's University); Dan Bernhardt (University of Illinois)
    Abstract: This paper characterizes long-run outcomes for broad classes of symmetric games, when players select actions on the basis of average historical performance. Received wisdom is that when agent's interests are partially opposed, behavior is excessively competitive: ``keeping up with the Jones' '' lowers everyones' welfare. Here, we study the long-run consequences of imitative behavior when agents have sufficiently long memories --- and the outcome is dramatically different. Imitation robustly leads to cooperative outcomes (with highest symmetric payoffs) in the long run. This provides a rationale, for example, for collusive cartel-like behavior without collusive intent on the part of the agents.
    Keywords: Evolution, Imitation
    JEL: C72 C73 D21 D43
    Date: 2006–01

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