Punishment with uncertain outcomes in the prisoner's dilemma

This paper experimentally investigates whether risk-averse individuals punish less if the outcome of punishment is uncertain than when it is certain. Our design includes three treatments: Baseline in which the one-shot prisoner’s dilemma game is played; Certain Punishment in which the prisoner’s dilemma game is followed by a punishment stage allowing subjects to decrease the other player’s payoff by 2 Euros; and Uncertain Punishment in which subjects could decrease the other player’s payoff with a 50% probability by 1 Euro and with a 50% probability by 3 Euros. We find that in all cases the risk-averse subjects are equally likely to cooperate in the prisoner’s dilemma and equally likely to punish in the second stage in either of the two punishment treatments.