Norm Enforcement in Markets: Group Identity and the Volunteering of Feedback

The provision of trader feedback is critical to the functioning of many markets. We examine the influence of group identity on the volunteering and informativeness of feedback. In a market experiment conducted simultaneously in Germany and the United States, we manipulate the interaction of traders based on natural social and induced home market identities. Traders are more likely to provide feedback information on a trader with whom they share a common group identity, and the effect is more pronounced for social identity than for home market identity. Both kinds of group identity promote rewarding good performance and punishing bad performance.