Simulation of an Optional Strategy in the Prisoner's Dilemma in Spatial and Non-spatial Environments

TL;DR

This study explores how the option to abstain influences strategy dynamics in the Prisoner's Dilemma across spatial and non-spatial settings, revealing conditions for cooperation to emerge and persist.

Contribution

It introduces an extended Prisoner's Dilemma with abstention and compares strategy outcomes in structured and unstructured environments using evolutionary game theory.

Findings

Abstention affects the stability of cooperation and defection.

Cooperative clusters can form and persist in both environments.

Environmental structure influences strategy success and cluster formation.

Abstract

This paper presents research comparing the effects of different environments on the outcome of an extended Prisoner's Dilemma, in which agents have the option to abstain from playing the game. We consider three different pure strategies: cooperation, defection and abstinence. We adopt an evolutionary game theoretic approach and consider two different environments: the first which imposes no spatial constraints and the second in which agents are placed on a lattice grid. We analyse the performance of the three strategies as we vary the loner's payoff in both structured and unstructured environments. Furthermore we also present the results of simulations which identify scenarios in which cooperative clusters of agents emerge and persist in both environments.