Do policy instruments that restrict social identity expression increase economic cooperation?

Recent public and corporate policies restricting social identity expression, such as the face-covering restrictions in many European countries, presume that prominent signals of our social identity differences drive division even when inference about social identity is unaffected. Social identity theory predicts that limiting identity expression could positively or negatively affect how groups interact. We use an experiment to test whether a treatment that bans displaying an identity pin affects cooperation in public goods provision. Our subjects are U.K. residents who were in favor of leaving or remaining in the European Union. Each subject is simultaneously in two different yet economically identical environments that are distinguished only by the social identities of the group members. They play two simultaneous one-shot public goods games, one with others who share their identity (in-group public good), and one with a mixture of Leavers and Remainers (mixed-group public good). The political identities of all subjects and the structure of each group are known by everyone. Our treatments vary whether there exists a ban on displaying a Leaver/Remainer identity pin to others and whether Leavers or Remainers are the majority identity in the mixed groups. We find that banning pinning increases contributions to the mixed group when Leavers are the majority. These increases can be explained by changes in beliefs rather than the notion that shared group identity per se affects behavior. These setting- and identity-specific results suggest that policies designed to promote integration should be examined in the context in which they will be applied.