Not that way! An Exploration of the Social Free-rider Problem as Cause of the Boomerang Effect from Social Norm Information

Social norms information is often used to nudge people towards prosocial behavior, yet, seldom results are unexpected and end in a boomerang effect that can potentially cause unintended harm. While there have been several explanations for why boomerang effects occur, the standard literature not always provide successful explanations. As these nudges are often used in campaigns of societal importance, it is valuable to understand under what circumstances the boomerang effect will occur. One cause of a boomerang effect that we explore is a social free-rider problem whereby the social norm information acts as a mechanism of updating prior probabilities on the actions of others. In this study, we formally propose a model of the social free-rider problem in the context of the boomerang effect from social norm information. Furthermore, we test our model predictions in a laboratory experiment through a modified dictator game with the option for punishment.