Quantifying the effects of punishing agents in a lattice-based prisoner's dilemma game

Abstract

Present day societies maintain a degree of order with a dedicated law enforcement body instead of individual-to-individual retaliation. In this study, we simulate the effect of such an arrangement through a prisoner's dilemma game on a grid. In addition to the basic types of strategies, the cooperator and defector, we added a third class of strategy behaving as punishers to mimic the effect of the enforcers in society. We observe nontrivial effects of punishers in the average payoff of the players, with certain configurations favoring the emergence of more rewarding conditions for cooperation than defection due to the presence of punishers. The insights derived from these \textit{in silico} experiments may help shed light on the emergence of the modern punishment mechanisms in society, which, empirically, are found to be robust despite the associated risks and costs.