Building Cooperative Networks

TL;DR

This paper investigates how cooperative networks can form and persist using evolutionary game theory, showing that increased connectivity and heterogeneity promote cooperation even as systems grow and incorporate defectors.

Contribution

It introduces conditions under which cooperative networks of any size and topology can form, reducing the benefit-cost ratio needed for cooperation to evolve in growing systems.

Findings

High cooperation levels are achievable with increased mean connectivity.

Heterogeneity among individuals is crucial for maintaining cooperation.

Conditions for cooperation are less restrictive in dynamic, growing networks.

Abstract

We study the cooperation problem in the framework of evolutionary game theory using the prisoner's dilemma as metaphor of the problem. Considering the growing process of the system and individuals with imitation capacity, we show conditions that allow to form highly cooperative networks of any size and topology. Introducing general considerations of real systems, we reduce the required conditions for cooperation to evolve approaching the benefit-cost ratio r to the theoretical minimum r=1, when the mean connectivity of the individuals is increased. Through the paper, we distinguish different mechanisms that allow the system to maintain high levels of cooperation when the system grows by incorporation of defectors. These mechanisms require heterogeneity among individuals for cooperation to evolve. However, the required conditions and heterogeneities are drastically reduced as compared to those required for static networks.