Austin McDonald and Sandip Sen
In some two-player games, e.g., the Prisoner’s Dilemma(PD), myopic decisions can produce poor performance both for the individual and the agent collection (society). When such games are played repeatedly between agents in a society, auxiliary mechanisms can be used to mitigate such lack of coordination. By biasing which other agents a particular agent can play, we can promote social coordination. Use of tags to limit partner selection for playing has been shown to produce stable cooperation in agent populations playing PD. There is, however, a lack of understanding of why sufficiently long tags are needed to achieve this effect. We empirically characterize the population features produced by longer tags that enable sustained cooperation. A theoretical analysis shows that similar effects can be obtained by increasing mutation rate and population size. Experiments partially validate these observations. We also predict that such increases may ultimately be detrimental at larger values.