The Effectiveness of Reward and Punishment in Spatial Social Games

摘要

Punishment and reward are usually regarded as two potential mechanisms to explain the evolution of cooperation especially among multiple participators. However, the performance of these two scenarios in spatial environment needs to be discussed. To figure out this issue, we resort to the n-player Iterated Snowdrift Dilemma (ISD) game and Iterated Prisoner's Dilemma (IPD) game. More importantly, the evolution of punishment and reward in social network structured populations has not been formally addressed. The numerical results show the equilibrium cooperation frequency can be influenced by cost-to-benefit ratio r, the punishment-to- benefit ratio p/b and the reward-to-benefit ratio r/b. And one intriguing observation is that under the same situation, the punishment is more effective than reward to the population. Then we further probe the effectiveness of neighborhood relationship to the cooperation, which is reflected by the random rewired probability pr. From the distribution of the four roles of the participator we can find that individuals can cooperate easily when they have close relationship. The results of this paper may be helpful to understand the cooperation in complex project or among industry-university-research cooperation project.