Extortion Boosts Cooperation through Redistributing Strategies in Assortative Networked Systems

Abstract

Networked evolutionary game theory is widely used to study the evolutionary dynamics in complex systems. In this work, we mainly investigate the influence of degree correlations of networks on the evolution of three memory-one strategies, i.e., unconditional cooperation, unconditional defection, and extortion. It is found that compared with the degree-uncorrelated network, assortative networks may inhibit the evolution of cooperation. The more assortative the network is, the less cooperation remains eventually. However, through micro dynamics analysis we reveal that by introducing extortion strategies, cooperation and defection are redistributed on the network, resulting in that cooperators can occupy the hub nodes while defectors survive among small-degree nodes. This work may provide potential clues to the coordination in multi-agent systems.