Endogenous Combination of Reward and Punishment Promotes Cooperation

How to promote cooperation is a long-discussed topic. With some defects followed, rewarding, punishing and mixed mechanisms have been proposed to finish this goal. Here, an endogenous combination of rewards and punishments is developed based on standard PGG aimed at inducing cooperative behavior and overcoming shortcomings in previous mechanisms. Under different key parameters, a trade-off can be observed in both static analysis and evolutionary simulation, which is the difficulty in solving social dilemmas. Under appropriate parameters, the simulation experiment proves that the mechanism proposed in this paper improves the contribution of groups to public utilities. Moreover, we also discovered that even in extremely passive environments, defectors do not turn strategy into cooperation. They wait and see, and if the conditions are still negative, then they cooperate. This phenomenon shows that individuals, even if they decide to change their strategies, are unwilling to undergo dramatic behavioral changes.