Consistent Rationalizability

Abstract

Consistency of a binary relation requires any preference cycle to involve indifference only. As shown by Suzumura (1976b), consistency is necessary and sufficient for the existence of an ordering extension of a relation. Because of this important role of consistency, it is of interest to examine the rationalizability of choice functions by means of consistent relations. We describe the logical relationships between the different notions of rationalizability obtained if reflexivity or completeness are added to consistency, both for greatest-element rationalizability and for maximal-element rationalizability. All but one notion of consistent rationalizability are characterized for general domains, and all of them are characterized for domains that contain all two-element subsets of the universal set.

Une relation de préférence est dite cohérente si les seuls cycles qu'elles contient sont des cycles d'indifférence. Nous étudions la \"rationalisabilité\" d'une fonction de choix par une relation de préférence cohérente.