Equality of opportunity and the acceptability of outcome inequality

In many real-world situations, unfairness of outcomes is not directly related to fairness-related properties of individual decisions; it is an unintended consequence of procedures in which individuals interact. Attitudes to such unfairness may be revealed in emotions of anger and resentment rather than in preferences over alternative decision outcomes. We conjecture that inequality is viewed with relatively little disfavour when it results from procedures that allow individuals equal strategic opportunities. We define a concept of procedural fairness which formalises intuitions about equality of opportunity. We report a Vendetta Game experiment in which negative attitudes to inequality can be expressed in costly and counter-productive ‘taking’ of co-players’ assets. A given degree of material inequality induces more taking if the procedure that has generated it is unfair rather than fair. Surprisingly, there is excess taking by players whom procedural unfairness has benefited as well as by those it has harmed.