Interdependent network reciprocity in evolutionary games

TL;DR

This paper demonstrates that interdependent network reciprocity can sustain public cooperation in adverse conditions through correlated cooperator clusters, but requires undisturbed coordination between networks.

Contribution

It introduces a model of interdependent networks with a utility function that promotes cooperation via correlated clusters, revealing conditions for successful interdependence.

Findings

Interdependent networks can maintain cooperation through correlated cooperator clusters.

Unbiased coupling enables spontaneous emergence of network reciprocity.

Disruption of coordination leads to collapse of cooperation.

Abstract

Besides the structure of interactions within networks, also the interactions between networks are of the outmost importance. We therefore study the outcome of the public goods game on two interdependent networks that are connected by means of a utility function, which determines how payoffs on both networks jointly influence the success of players in each individual network. We show that an unbiased coupling allows the spontaneous emergence of interdependent network reciprocity, which is capable to maintain healthy levels of public cooperation even in extremely adverse conditions. The mechanism, however, requires simultaneous formation of correlated cooperator clusters on both networks. If this does not emerge or if the coordination process is disturbed, network reciprocity fails, resulting in the total collapse of cooperation. Network interdependence can thus be exploited effectively to promote cooperation past the limits imposed by isolated networks, but only if the coordination between the interdependent networks is not disturbed.