Indirect reciprocity (IR) is an important mechanism for promoting cooperation among self-interested agents. Simplified, it means: “you help me, therefore somebody else will help you” (in contrast to direct reciprocity: “you help me; therefore I will help you”). IR can be achieved via reputation and norms. However, it was often argued that IR only works if reputations are public and does not do so under private assessment (PriA). Yet, recent papers suggest that IR under PriA is feasible, and that it has more variety and ways to improve, than have been considered before.

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