Evolution of public cooperation in a monitored society with implicated punishment and within-group enforcement

TL;DR

This paper demonstrates that monitoring with implicated punishment and within-group enforcement effectively promotes public cooperation, revealing complex group-size effects that influence collective action in human societies.

Contribution

It provides a theoretical analysis showing how monitoring and enforcement transform public goods games into coordination games, highlighting the impact of group size on cooperation.

Findings

Monitoring transforms public goods games into coordination games.

Within-group enforcement further enhances cooperation.

Intermediate group sizes are less conducive to cooperation.

Abstract

Monitoring with implicated punishment is common in human societies to avert freeriding on common goods. But is it effective in promoting public cooperation? We show that the introduction of monitoring and implicated punishment is indeed effective, as it transforms the public goods game to a coordination game, thus rendering cooperation viable in infinite and finite well-mixed populations. We also show that the addition of within-group enforcement further promotes the evolution of public cooperation. However, although the group size in this context has nonlinear effects on collective action, an intermediate group size is least conductive to cooperative behaviour. This contradicts recent field observations, where an intermediate group size was declared optimal with the conjecture that group-size effects and within-group enforcement are responsible. Our theoretical research thus clarifies key aspects of monitoring with implicated punishment in human societies, and additionally, it reveals fundamental group-size effects that facilitate prosocial collective action.