How Paulus Becomes Saulus An Experimental Study of Equal Punishment Games

In equal punishment games like in ultimatum games first a proposer suggests how to split the pie, i.e. a positive monetary reward. Unlike in ultimatum games, the responder can decide among many (for proposer and responder) equal penalty payments. To exclude negative payoffs, punishment was bounded from above by the sum of the offer and the (for proposer and responder) same show up-fee, our only treatment variable. Although inequality aversion predicts zero-punishments, we observe positive punishments which however, decrease with experience, Initial fairness, 1/3 of initial offers were equal splits, is often substituted in the repetition by greed. Whereas greed is sticky, fairness seems to be an initial inclination but unstable.