Commitment in symmetric contests

The paper proves that in two-player logit form symmetric contests with concave success function, commitment to a particular strategy does not increase a player's payoff, while in contests with more than two players it does. The paper also provides a contest-like game in which commitment does not increase a player's payoff for any number of players

Evolutionary Stability of Constant Consistent Conjectures

The paper shows that there is a close connection between (constant) consistent conjectures in a given game and evolutionary stability of conjectures. Evolutionarily stable conjectures are consistent and consistent conjectures are the only interior candidates for evolutionary stability.consistent conjectures, evolutionarily stable strategy, indirect evolution

Cooperative Prisoners and Aggressive Chickens: Evolution of Strategies and Preferences in 2x2 Games

By means of simulations I investigate a two-speed dynamic on strategies and preferences in the prisoners' dilemma and in the chicken game. Players learn strategies according to their preferences while evolution leads to a change in preference composition. With complete information cooperation in the prisoners' dilemma is often achieved, with 'reciprocal' preferences. In the chicken game a symmetric correlated strategy profile is played that is as efficient as the symmetric equilibrium. Among preferences only pure 'hawkish' preferences and 'selfish' preferences survive. With incomplete information, the symmetric equilibrium of the material payoff game is played. All types of preferences are present in the population in the medium run.

Commitment in symmetric contests

The paper proves that in two-player logit form symmetric contests with concave success function, commitment to a particular strategy does not increase a player's payoff, while in contests with more than two players it does. The paper also provides a contest-like game in which commitment does not increase a player''s payoff for any number of players.

Two-Speed Evolution of Strategies and Preferences in Symmetric Games

Agenst in a large population are randomly matched to play a material payoff game. They may have preferences that are different from the material payoffs. Agents learn equilibrium strategies according to their preferences before evolution changes the preference distribution in the population according to fitness. When agents know the preferences of the opponent in a match, only efficient symmetric strategy profiles of the material payoff game can be stable. When agents do not know the preferences of the opponent, only Nash equilibria of the material payoff game can be stable. For 2x2 symmetric games I characterize preferences that are stable.

Commitment in Symmetric Contests

The paper proves that in two-player logit form symmetric contests with concave success function, commitment to a particular strategy does not increase a player's payoff, while in contests with more than two players it does. The paper also provides a contest-like game in which commitment does not increase a player's payoff for any number of players.contests, commitment

Evolution in Symmetric Incomplete Information Games

The paper compares two models of evolution in symmetric two-player games with incomplete information. One model postulates that the type of a player is fixed, and evolution works within types. In the other model type-contingent strategies evolve. In the case of two types and two strategies it is shown that the stability properties of stationary states are the same under the two dynamics when payoffs do not depend on the type of the other player, but may differ when they do.incomplete information games, evolution, stability

The evolutionary stability of constant consistent conjectures

In the general context of smooth two-player games, this paper shows that there is a close connection between (constant) consistent conjectures in a given game and the evolutionary stability of these conjectures. Evolutionarily stable conjectures are consistent and consistent conjectures are the only interior candidates to be evolutionarily stable. Examples are provided to illustrate the result

Conjectural variations in aggregative games: an evolutionary perspective

Suppose that in symmetric aggregative games, in which payoffs depend only on a player's strategy and on an aggregate of all players' strategies, players have conjectures about the reaction of the aggregate to marginal changes in their strategy. The players play a conjectural variation equilibrium, which determines their fitness payoffs. The paper shows that only consistent conjectures can be evolutionarily stable in an infinite population, where a conjecture is consistent if it is equal to the marginal change in the aggregate determined by the actual best responses. In the finite population case, only zero conjectures representing aggregate-taking behavior can be evolutionarily stable

Common value allocation mechanisms with private information: Lotteries or auctions?

We consider mechanisms for allocating a common-value prize between two players in an incomplete information setting. In this setting, each player receives an independent private signal about the prize value. The signals are from a discrete distribution and the value is increasing in both signals. First, we characterize symmetric equilibria in four mechanisms: a lottery; and first-price, second-price, and all-pay auctions. Second, we establish revenue equivalence of these auction mechanisms in this setting. Third, we describe conditions under which the expected revenue is higher in the lottery than in any of the auctions. Finally, we identify an optimal mechanism and its implementation by means of reserve prices in lottery and auction mechanisms