A measure of choice irrationality based on opposite judgements

Abstract

In many choice settings the decision maker (DM) adopts a criterion which is a mediation between her preference, and its opposite. According to such compromise, the first i alternatives on top of the DM's taste are moved, in reverse order, to the bottom. This pattern allows to define the compromise-based degree of irrationality, which quantifies the extent of the mediation embraced by the DM in her choice. Necessary and sufficient conditions characterizing this index are singled out. I investigate non rationalizable choices that display the lowest degree of irrationality, and I fully identify the preferences that explain the DM's picks by a minimal mediation between opposite judgments. These datasets account for some well known selection biases, such as second-best procedures, and the handicapped avoidance. I offer a simple characterization of the choice behavior that exhibits the most severe compromise, and I show that this subclass comprises almost all choices. Finally, some alternative measures of compromise are characterized, and compared with the score previously determined.