Effects of co-players’ identity and reputation in the public goods game

Players’ identity and their reputation are known to influence cooperation in economic games, but littleis known about how they interact. Our study aimed to understand how presenting pre-programmedco-players’ identities (face photos; names) along with their previous cooperation history (reputation)could influence participants’ cooperative decisions in a public goods game. Participants (N= 759) wereallocated to one of six experimental groups: (i) control (no information); (ii) only reputation (neutral, freerider, or cooperative); (iii) only face; (iv) face with reputation; (v) only name; (vi) name with reputation. Inthe reputation group, cooperation significantly decreased when free-riders were playing and significantlyincreased when they were cooperators. Person’s identity affected cooperativeness only when combinedwith reputation: face photo mitigated the negative effect of the free-rider reputation, while name identitymitigated any significant effect expected for reputation. Our study suggests a hierarchy: reputationchanges cooperation, but a person’s identity can modulate reputation.