Risk and Retribution: How Punishment Uncertainty Weakens Norms of Cooperation

Studies have demonstrated that certain sanctioning institutions can play an essential role in maintaining human cooperation in public goods experiments. However, in reality, the outcome of sanctions can be subject to stochasticity. In a public goods experiment with peer punishment, we investigated the comparative advantage of certain versus uncertain sanctioning institutions by allowing participants to repeatedly choose between the two. In one institution, sanctions issued by individuals were multiplied by three, while in another, the consequences of sanctions were multiplied by a random factor between 0 and 6. Initially, the uncertain institution was the majority choice, but it eventually tended to become the minority choice. We found less punishment, due to less antisocial punishment, in a certain institution, leading to higher contributions and payoffs. Hence, when participants learned about the difference in payoffs, they chose a certain sanctioning institution more often. Especially, prosocial and risk-averse individuals with strong contribution norms were more likely to choose certainty. Additionally, we investigated the motives that may influence pro- and antisocial punishment, as they influence an institution's success. We find that hypersensitivity to punishment, non-prosocial punishment motives, weak contribution norms, and normative hubris reduce the effectiveness of sanctions in establishing cooperation.