Supervised cooperation on interdependent public goods games

TL;DR

This paper models the coevolution of strategies and judgment in public goods games using interdependent networks, revealing how fines and bribes influence the emergence of cooperation among self-interested agents.

Contribution

It introduces a novel interdependent network model for public goods games that incorporates strategy, judgment, and corruption dynamics, highlighting the impact of fines and bribes on cooperation.

Findings

Large fines and bribes promote cooperation by lowering the threshold for coexistence of strategies.

Bribes can be as effective as harsh fines in fostering cooperation.

Correlations between cooperators and fair referees are key to system behavior.

Abstract

It is a challenging task to reach global cooperation among self-interested agents, which often requires sophisticated design or usage of incentives. For example, we may apply supervisors or referees who are able to detect and punish selfishness. As a response, defectors may offer bribes for corrupt referees to remain hidden, hence generating a new conflict among supervisors. By using the interdependent network approach, we model the key element of the coevolution between strategy and judgment. In a game layer, agents play public goods game by using one of the two major strategies of a social dilemma. In a monitoring layer, supervisors follow the strategy change and may alter the income of competitors. Fair referees punish defectors while corrupt referees remain silent for a bribe. Importantly, there is a learning process not only among players but also among referees. Our results suggest that large fines and bribes boost the emergence of cooperation by significantly reducing the phase transition threshold between the pure defection state and the mixed solution where competing strategies coexist. Interestingly, the presence of bribes could be as harmful for defectors as the usage of harsh fines. The explanation of this system behavior is based on a strong correlation between cooperators and fair referees, which is cemented via overlapping clusters in both layers.