Powering up with indirect reciprocity in a large-scale field experiment

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 110; no. Supplement 2; pp. 10424 - 10429
• Main Authors: Yoeli, Erez, Hoffman, Moshe, Rand, David G., Nowak, Martin A.
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences 18.06.2013; National Acad Sciences
• Subjects: Adult; Biological Evolution; Biological Sciences; Blackouts; Cooperation; Cooperative Behavior; Energy consumption; Evolution; Experiments; Female; field experimentation; Field experiments; Field study; Financial incentives; games; Games, Experimental; Humans; In the Light of Evolution VII: The Human Mental Machinery Sackler; issues and policy; Male; Models, Biological; natural selection; Participant observation; Public goods; public services and goods; Reciprocity; Social evolution; Social interaction; Social Sciences; utilities; evolutionary game theory; experimental economics
• DOI: 10.1073/pnas.1301210110
• ISSN: 0027-8424; 1091-6490

A defining aspect of human cooperation is the use of sophisticated indirect reciprocity. We observe others, talk about others, and act accordingly. We help those who help others, and we cooperate expecting that others will cooperate in return. Indirect reciprocity is based on reputation, which spreads by communication. A crucial aspect of indirect reciprocity is observability: reputation effects can support cooperation as long as peoples’ actions can be observed by others. In evolutionary models of indirect reciprocity, natural selection favors cooperation when observability is sufficiently high. Complimenting this theoretical work are experiments where observability promotes cooperation among small groups playing games in the laboratory. Until now, however, there has been little evidence of observability’s power to promote large-scale cooperation in real world settings. Here we provide such evidence using a field study involving 2413 subjects. We collaborated with a utility company to study participation in a program designed to prevent blackouts. We show that observability triples participation in this public goods game. The effect is over four times larger than offering a $25 monetary incentive, the company’s previous policy. Furthermore, as predicted by indirect reciprocity, we provide evidence that reputational concerns are driving our observability effect. In sum, we show how indirect reciprocity can be harnessed to increase cooperation in a relevant, real-world public goods game.