AbstractA long history in economics going back to Adam Smith has argued that people give primacy to merit—rather than luck—in distributive choices. We provide a theoretical framework formalising the merit primacy effect, and study it in a novel experiment where third-party spectators redistribute from high earners to low earners in situations where both merit and luck determine earnings. We identify a strong and consistent merit primacy effect in the spectator behaviour. The results shed new light on inequality acceptance in society, by showing how just a little bit of merit can make people significantly more inequality accepting.