Indirect reciprocity can overcome free-rider problems on costly moral assessment

TL;DR

This paper proposes a pre-assessment mechanism for indirect reciprocity that effectively stabilizes cooperation by penalizing cost evaders, addressing a key vulnerability in moral assessment systems.

Contribution

It introduces a simple, broadly applicable pre-assessment method that enhances the stability of cooperative states in indirect reciprocity models.

Findings

Pre-assessment stabilizes cooperation against cost evaders.

Most social norms become stable with pre-assessment.

The method broadens the applicability of indirect reciprocity models.

Abstract

Indirect reciprocity is one of the major mechanisms of the evolution of cooperation. Because constant monitoring and accurate evaluation in moral assessments tend to be costly, indirect reciprocity can be exploited by cost evaders. A recent study crucially showed that a cooperative state achieved by indirect reciprocators is easily destabilized by cost evaders in the case with no supportive mechanism. Here, we present a simple and widely applicable solution that considers pre-assessment of cost evaders. In the pre-assessment, those who fail to pay for costly assessment systems are assigned a nasty image that leads to being rejected by discriminators. We demonstrate that considering the pre-assessment can crucially stabilize reciprocal cooperation for a broad range of indirect reciprocity models. In particular for the most leading social norms we analyse the conditions under which a prosocial state becomes locally stable.