Cooperation in teams: The role of identity, punishment, and endowment distribution

•We test the role of identity, endowment heterogeneity and punishment on teamwork.•We conduct a repeated public good experiment.•Strong identity counteracts the negative impact of endowment heterogeneity.•Punishment increases cooperation if identity is weak, but the effect is less clear-cut if identity is strong.

Common identity and peer punishment have been identified as crucial means to reduce free riding and promote cooperation in teams. This paper examines the relative importance of these two mechanisms under two income distributions in team cooperation. In a repeated public good experiment, we use different combinations of homogeneous/heterogeneous endowments, strong/weak identity, and absence/presence of peer punishment. We find that without punishment, a strong identity can raise cooperation in homogenous and heterogeneous teams, but that the effect depends on the strength of the identity. When punishment is introduced, the impact of punishment depends on the strength of the identity-building activity and the effectiveness of punishment. Furthermore, we find no evidence of stronger cooperation or punishment in teams with strong identity. These findings provide important implications for management policy makers in organizations: ex ante income heterogeneity should be implemented in teams with caution, and the decision of whether identity or punishment is a more effective norm enforcement mechanism in teams is rather sensitive to their interaction and relative strengths.