Cooperation in Networked Collective-Action Groups: Information Access and Norm Enforcement in Groups of Different Sizes

Norms, typically enforced via sanctions, are key to resolving collective-action problems. But it is often impossible to know what each individual member is contributing to group efforts and enforce cooperation accordingly. Especially as group size increases, people commonly have access to the behaviors of-and can sanction-only those to whom they are tied in a broader network. Here we integrate two streams of research: one conceptualizing ties in networked collective-action groups as access to information about what others are doing and a second where ties represent information plus opportunities to enforce cooperation via punishment. While both have pointed to the cooperation benefits of more ties in the network, we argue that these benefits will depend on group size and whether ties provide access to information about what others are doing or whether they also entail opportunities for norm enforcement. Our experiment demonstrates that densely tied information networks facilitate cooperation but only when the group size is small. When people can also enforce their ties' cooperation, however, densely tied networks particularly benefit larger groups. The results demonstrate how network-level properties and individual-level tie patterns intersect to promote contributions in small and large collective-action groups.