The Consistency of Fairness Rules: An Experimental Study

In the last two decades, experimental papers on distributive justice have abounded. Two main results have been replicated. Firstly, there is a multiplicity of fairness rules. Secondly, fairness decisions differ depending on the context. This paper studies individual consistency in the use of fairness rules, as well as the structural factors that lead people to be inconsistent. We use a within-subject design, which allows us to compare individual behavior when the context changes. In line with the literature, we find a multiplicity of fairness rules. However, when we control for consistency, the set of fairness rules is considerably smaller. Only selfishness and strict egalitarianism seem to survive the stricter requirement of consistency. We observe that this result is mainly explained by a self-serving bias. Participants select the rule that is individually optimal in each situation.