The Evolution of Quantitatively Responsive Cooperative Trade (original) (raw)

The emergence of reciprocally beneficial cooperation

2010

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.

Evolutionary dynamics of cooperation under the distributed prisoner's dilemma

Lecture Notes of the Institute for Computer Sciences, Social-Informatics and Telecommunications Engineering, 2012

Humans contribute to a broad range of cooperative endeavors. In many of them, the amount or effort contributed often depends on the social context of each individual. Recent evidence has shown how modern societies are grounded in complex and heterogeneous networks of exchange and cooperation, in which some individuals play radically different roles and/or interact more than others. We show that such social heterogeneity drastically affects the behavioral dynamics and promotes cooperative behavior, whenever the social dilemma perceived by each individual is contingent on her/his social context. The multiplicity of roles and contributions induced by realistic population structures is shown to transform an initial defection dominance dilemma into a coordination challenge or even a cooperator dominance game. While locally defection may seem inescapable, globally there is an emergent new dilemma in which cooperation often prevails, illustrating how collective cooperative action may emerge from myopic individual selfishness.

Variable investment, the Continuous Prisoner's Dilemma, and the origin of cooperation

Proceedings of the Royal Society B: Biological Sciences, 1999

Cooperation is fundamental to many biological systems. A common metaphor for studying the evolution of cooperation is the Prisoner's Dilemma, a game with two strategies: cooperate or defect. However, cooperation is rarely all or nothing, and its evolution probably involves the gradual extension of initially modest degrees of assistance. The inability of the Prisoner's Dilemma to capture this basic aspect limits its use for understanding the evolutionary origins of cooperation. Here we consider a framework for cooperation based on the concept of investment: an act which is costly, but which bene¢ts other individuals, where the cost and bene¢t depend on the level of investment made. In the resulting Continuous Prisoner's Dilemma the essential problem of cooperation remains: in the absence of any additional structure non-zero levels of investment cannot evolve. However, if investments are considered in a spatially structured context, sel¢sh individuals who make arbitrarily low investments can be invaded by higher-investing mutants. This results in the mean level of investment evolving to signi¢cant levels, where it is maintained inde¢nitely. This approach provides a natural solution to the fundamental problem of how cooperation gradually increases from a non-cooperative state.

Rational actors, tit-for-tat types, and the evolution of cooperation

Journal of Economic Behavior & Organization, 1996

Evolutionary models in economics have often been criticized for failing to allow for rational, maximizing behavior. The present paper represents a step toward correcting this deficiency, by introducing rational actors into an evolutionary model of the finitely repeated Prisoners' Dilemma. At the same time, the model endogenizes the uncertainty postulated in the classic model of Kreps et al. (1982), thus explaining cooperation by rational actors in the finitely repeated Prisoners' Dilemma. A testable implication of the model is that the level of voluntary cooperation in a society will be relatively high where geographical mobility is relatively low. JEL clu,ssification: C72; C73

MATCHING STRUCTURE AND THE EVOLUTION OF COOPERATION IN THE PRISONER’S DILEMMA

With the help of both an experiment and analytical techniques, Axelrod and Hamilton [1] showed that cooperation can evolve in a Prisoner’s Dilemma game when pairs of individuals interact repeatedly. They also demonstrated that, when pairing of individual is not completely random, cooperating behaviour can evolve in a world initially dominated by defectors. This result leads us to address the following question: Since non-random pairing is a powerful mechanism for the promotion of cooperation in a repeated Prisoner’s Dilemma game, can this mechanism also promote the evolution of cooperation in a nonrepeated version of the game? Computer simulations are used to study the relation between non-random pairing and the maintenance of cooperative behaviour under evolutionary dynamics. We conclude that non-random pairing can secure cooperation also when the possibility of repeated interaction among the same pairs of individuals is ruled out.

Models of cooperation based on the Prisoner's Dilemma and the Snowdrift game

Ecology Letters, 2005

Understanding the mechanisms that can lead to the evolution of cooperation through natural selection is a core problem in biology. Among the various attempts at constructing a theory of cooperation, game theory has played a central role. Here, we review models of cooperation that are based on two simple games: the Prisoner's Dilemma, and the Snowdrift game. Both games are two-person games with two strategies, to cooperate and to defect, and both games are social dilemmas. In social dilemmas, cooperation is prone to exploitation by defectors, and the average payoff in populations at evolutionary equilibrium is lower than it would be in populations consisting of only cooperators. The difference between the games is that cooperation is not maintained in the Prisoner's Dilemma, but persists in the Snowdrift game at an intermediate frequency. As a consequence, insights gained from studying extensions of the two games differ substantially. We review the most salient results obtained from extensions such as iteration, spatial structure, continuously variable cooperative investments, and multi-person interactions. Bridging the gap between theoretical and empirical research is one of the main challenges for future studies of cooperation, and we conclude by pointing out a number of promising natural systems in which the theory can be tested experimentally.