Cooperation and Anonymity: Does the Revelation of Group Members’ Identities Affect Contributions in an Artefactual Public Good Field Experiment?

Abstract

Social dilemmas in the real world, such as pollution and extraction of resources, often differ regarding visibility of involved parties and their behavior. While publicly disclosing individual decisions in social dilemma situations is known to result in more cooperation, little research has been done on whether it makes a difference if individual identities are revealed or kept anonymous. This study uses an artefactual public good field experiment conducted in rural Namibia with 144 villagers, who are randomly assigned to one of two experimental conditions: An “anonymity” condition preserves anonymity of group members, whereas identities are revealed in an “identification” condition. Individual contributions to the public good remain anonymous in both cases, so the difference between the two conditions only lies in whether participants get to see who their group members are. In addition, the experiment’s setting in village communities entails pre-existing social ties between participants, which allow investigating the role of group composition, such as the share of friends and family members, and likely amplify potential effects that revealing identities can have on cooperation. Results show that contributions to the public good are significantly higher in the “anonymity” condition than in the “identification” condition, which can be explained by theories of social identity and depersonalization, specifically the “social identity model of deindividuation effects” (Reicher et al. 1995). The variability of contributions, measured as standard deviations, does not turn out as different across the two experimental conditions. Exploratory analyses further reveal that contributions in the “identification” condition are distinctly lower when group members are socially distant to each other.

Keywords: anonymity, cooperation, artefactual field experiment, public good, social identity, depersonalization

JEL Classification: C71, C93, D8, D9, H41, Q5, Z1