Score contribution per author:
α: calibrated so average coauthorship-adjusted count equals average raw count
This paper explores the motivations behind punishment from unaffected third parties and affected second parties using a within-subjects design in ten simple games. We apply a classification analysis and find that a parsimonious model assuming that subjects are either inequity averse or selfish best explains the pattern of punishment from both third and second parties. Despite their unaffected position, we find that many third parties do not punish in an impartial or normative manner.