Impact of link deletions on public cooperation in scale-free networks

TL;DR

This paper investigates how removing links from high-degree nodes in scale-free networks impacts cooperation in public goods games, revealing mostly negative effects but also some optimal conditions for cooperation deterioration.

Contribution

It introduces an analysis of link deletion effects on cooperation in multi-group public goods games on scale-free networks, highlighting the importance of social diversity.

Findings

Link deletions generally harm cooperation.

An optimal number of link removals can deteriorate cooperation.

Social diversity is crucial for cooperation evolution.

Abstract

Working together in groups may be beneficial if compared to isolated efforts. Yet this is true only if all group members contribute to the success. If not, group efforts may act detrimentally on the fitness of their members. Here we study the evolution of cooperation in public goods games on scale-free networks that are subject to deletion of links that are connected to the highest-degree individuals, i.e., on networks that are under attack. We focus on the case where all groups a player belongs to are considered for the determination of payoffs; the so-called multi-group public goods games. We find that the effect of link deletions on the evolution of cooperation is predominantly detrimental, although there exist regions of the multiplication factor where the existence of an "optimal" number of removed links for deterioration of cooperation can also be demonstrated. The findings are explained by means of wealth distributions and analytical approximations, confirming that socially diverse states are crucial for the successful evolution of cooperation.