「選択の多様性」の評価に関する理論的研究

抄録

This paper discusses evaluation measures for flexibility of “opportunity sets”, from which a consumer chooses objects over time. In particular, it concerns binary relations on the opportunity sets which satisfy an axiom for “preference for flexibility”; a consumer is assumed to possess state dependent preferences for objects; a set x is supposed to be preferred to x'; in terms of flexibility in choice, if and only if, no matter what state ensues, there is something in x as good as everything in x'. We present a general form of evaluation indices for flexibility in choice, which are relevant numerical representations of an underlying preference on sets. Log-sum utility measures derived from random utility theory may belong to the general class of indices for the evaluation of flexibility in choice.