Social capital is associated with cooperation and indirect norm enforcement in the field: behavioural evidence from Switzerland

Social capital, comprising networks, generalized trust, and cooperation norms, is often considered a key factor in promoting prosperity and cooperation. Informal norm enforcement also drives cooperation. While early theories of social capital and norm enforcement propose that networks encourage sanctions, strong reciprocity theory argues that sanctioning non-cooperation is a universal preference. In the lab, people uphold cooperation through sanctions without networks, but this occurs only in regions characterized by high trust levels and strong cooperation norms outside the laboratory. Are trust, cooperation, and enforcement linked in the field, and if so, what are the generative mechanisms? In two neighbourhoods of Bern, one high in social capital and one low, we linked indicators of social capital and expected norm compliance from resident surveys (N = 466) with cooperation, measured with the lost-letter technique (N = 240), and norm enforcement, measured with reactions to transgressions of the antilittering norm (N = 123). Cooperation and indirect enforcement were more prevalent in the high social capital neighbourhood. Direct enforcement was rare in both neighbourhoods. The less optimistic expectations of cooperation and norm compliance prevalent in the low social capital neighbourhood can potentially explain the lower levels of cooperation and norm enforcement.