We study individuals who can choose how to compete with an opponent for one nonzero payoff. They can either nudge themselves into a fair set of rules where they have the same information and actions as their opponent, or into unfair rules where they spy, sabotage or fabricate their opponent's...

We assess the predictive power of a model of other-regarding preferences - inequality aversion - using a within-subjects design. We run four different experiments (ultimatum game, dictator game, sequential-move prisoners' dilemma and public-good game) with the same sample of subjects. We elicit...