Evolutionary Dynamics of Reputation-Based Voluntary Prisoner's Dilemma Games

TL;DR

This paper investigates how reputation-based voluntary participation, combined with exit incentives, influences the evolution and stability of cooperation in Prisoner's Dilemma games across different population structures.

Contribution

It introduces a novel reputation-based voluntary Prisoner's Dilemma model incorporating exit incentives and analyzes its effects on cooperation dynamics in various population structures.

Findings

Reputation-conditioned exit sustains cooperation through multiple coexistence pathways.

In well-mixed populations, stable mixed cooperation and defection coexist.

Structured populations exhibit cyclic dominance and oscillations depending on exit incentives.

Abstract

Cooperation underlies many natural and artificial systems. While voluntary participation can sustain cooperation without informational assumptions, real interactions are rarely anonymous, leaving the joint effects of participation and reputation insufficiently understood. We propose a reputation-based voluntary Prisoner's Dilemma in which agents incur a monitoring cost to inspect opponents and decide whether to exit an interaction for a fixed incentive to avoid exploitation or to default to cooperation or defection. We show that reputation-conditioned exit generates multiple coexistence pathways that sustain cooperation across population structures. In well-mixed populations, cooperation persists through stable mixed coexistence, whereas in structured populations, exit-incentive-dependent regimes emerge, including local cyclic dominance and persistent oscillations. Together, these results extend voluntary participation frameworks and underscore the role of exit-incentive design in cooperative multi-agent systems.