Promotion of cooperation by payoff-driven migration

Migration plays an important role in the evolution of cooperation. Previous studies concerning mobile population often assumed that all agents move with the identical velocity. In this paper, we propose a payoff-driven migration in which the velocity of an agent depends on his/her payoff. A parameter alpha is introduced to adjust the influence of payoff, when alpha = 0 means that agents all move with the identical velocity while alpha > 0 means that the lower the payoff is, the faster the moving speed is, and vice versa. For the prisoner's dilemma game, we find that in comparison with the case that agents all move with the same speed, cooperation could be promoted strongly when payoff-dependent velocity is considered. Remarkably, the cooperation level is not a monotonic function of alpha, and there exists an optimal value of alpha which can lead to the maximum cooperation level. For the snowdrift game, the cooperation level increases with alpha. (C) 2016 Elsevier B.V. All rights reserved.