The emergence of reciprocally beneficial cooperation

This paper offers a new and robust model of the emergence and persistence of cooperation. In the model, interactions are anonymous, the population is well-mixed, and the evolutionary process selects strategies according to material payoffs. The cooperation problem is modelled as a game similar to Prisoner’s Dilemma, but there is an outside option of nonparticipation and the payoff to mutual cooperation is stochastic; with positive probability, this payoff exceeds that from cheating against a cooperator. Under mild conditions, mutually beneficial cooperation occurs in equilibrium. This is possible because the non-participation option holds down the equilibrium frequency of cheating.Cooperation; voluntary participation; random payoffs.

PSEUDORANDOM PROCESSES: ENTROPY AND AUTOMATA

This paper studies implementation of cooperative payoffs in finitely repeated games when players implement their strategies by finite automata of big sizes. Specifically, we analyze how much we have to depart from fully rational behavior to achieve the Folk Theorem payoffs, i.e., which are the maximum bounds on automata complexity which yield cooperative behavior in long but not infinite interactions. To this end we present a new approach to the implementation of the mixed strategy equilibrium paths leading to cooperation. The novelty is to offer a new construction of the set of the pure strategies which belong to the mixed strategy equilibrium. Thus, we consider the subset of strategies which is characterized by both the complexity of the finite automata and the entropy associated to the underlying coordination process. The equilibrium play consists of both a communication phase and the play of a cycle which depends on the chosen message. The communication set is designed by tools of Information Theory. Moreover, the characterization of this set is given by the complexity of the weaker player that implements the equilibrium play. We offer a domain of definition of the smallest automaton which includes previous domains in the literature.Complexity; Cooperation; Entropy; Automata; Repeated Games.

Global Dynamics in Infinitely Repeated Games with Additively Separable Continuous Payoffs

This paper studies a class of infinitely repeated games with two players in which the action space of each player is an interval, and the one-shot payoff of each player is additively separable in their actions. We define an immediately reactive equilibrium (IRE) as a pure-strategy subgame perfect equilibrium such that each player's action in each period is a stationary function of the other player's last action. We completely characterize IREs and their dynamics in terms of certain indifference curves. In a special case we establish a folk-type theorem using only IREs that are continuous and punish deviations in a minimal way. Our results are used to show that in a prisoners' dilemma game with observable mixed strategies, gradual cooperation occurs when the players are sufficiently patient, and that in a certain duopoly game, kinked demand curves emerge naturally.Immediately reactive equilibria, Additively separable pay-offs, Kinked demand, Gradual cooperation, Prisoners'dilemma

The emergence of reciprocally beneficial cooperation

We offer a new and robust model of the emergence and persistence of cooperation when interactions are anonymous, the population is well-mixed, and evolution selects strategies according to material payoffs. The model has a Prisoner’s Dilemma structure, but with an outside option of non-participation. The payoff to mutual cooperation is stochastic; with positive probability, it exceeds that from cheating against a cooperator. Under mild conditions, mutually beneficial cooperation occurs in equilibrium. This is possible because the non-participation option holds down the equilibrium frequency of cheating. Dynamic properties of the model are investigated theoretically and through simulations based on replicator dynamics

Trust and Reciprocity in Incentive Contracting

Principals can attempt to get agents to perform certain actions preferable to the principal by using ex post}punishments and rewards to align incentives. Field data is mixed on whether, and to what extent, such informal incentive contracting (paradoxically) crowds out efficient solutions to the agency problem. This paper explores, via a novel set of laboratory experiments, the impact of ex post incentives on informal contracts between principals and agents in bargaining environments in which there are gains from exchange and when there is an opportunity for the principal to relay a no-cost demand of the division of those gains. Incentive contracting in these environments does not crowd-out off- equilibrium cooperation, and at high incentive levels cooperation is crowded in.incentives, principal-agent, bargaining, trust, cooperation, punishment, reward

Trust and reciprocity in incentive contracting

Principals can attempt to get agents to perform certain actions preferable to the principal by using ex post punishments or rewards to align incentives. Field data is mixed on whether, and to what extent, such informal incentive contracting (paradoxically) crowds out efficient solutions to the agency problem. This paper explores, via a novel set of laboratory experiments, the impact of ex post incentives on informal contracts between principals and agents in bargaining environments in which there are gains from exchange and when there is an opportunity for the principal to relay a no-cost demand of the division of those gains. Incentive contracting in these environments does not crowd-out off-equilibrium cooperation, and at high incentive levels cooperation is crowded in.incentives; trust; reciprocity; organizations; experimental economics

Formation of coalition structures as a non-cooperative game

Traditionally social sciences are interested in structuring people in multiple groups based on their individual preferences. This pa- per suggests an approach to this problem in the framework of a non- cooperative game theory. Definition of a suggested finite game includes a family of nested simultaneous non-cooperative finite games with intra- and inter-coalition externalities. In this family, games differ by the size of maximum coalition, partitions and by coalition structure formation rules. A result of every game consists of partition of players into coalitions and a payoff? profiles for every player. Every game in the family has an equilibrium in mixed strategies with possibly more than one coalition. The results of the game differ from those conventionally discussed in cooperative game theory, e.g. the Shapley value, strong Nash, coalition-proof equilibrium, core, kernel, nucleolus. We discuss the following applications of the new game: cooperation as an allocation in one coalition, Bayesian games, stochastic games and construction of a non-cooperative criterion of coalition structure stability for studying focal points.Comment: arXiv admin note: text overlap with arXiv:1612.02344, arXiv:1612.0374