Shrinking the moral wiggle room: The role of social norms under attributional ambiguity

Giving may decrease in ambiguous settings, when individuals can better justify acting selfishly. This paper examines how attributional ambiguity affects giving behavior and whether normative messages can counteract these effects. In an incentivized experiment, participants can donate up to half of their earnings to non-profit organizations supporting the energy transition. We show that ambiguity decreases the probability of prosocial contributions. This is consistent with the theory of moral wiggle room, in which individuals exploit ambiguity in self-serving ways. We also find that perceived descriptive norms strongly moderate this behavior individuals with positive beliefs about others' prosociality are strongly affected by ambiguity, while individuals with negative beliefs remain largely insensitive. The counteracting effect of an injunctive fairness-based message remains partial and limited to participants with positive descriptive beliefs.