This paper concerns individual choice among from which the individual will later choose a single object. In particular, it concerns relations on opportunity sets which satisfy preference for flexibility, a set is at least as good as all of its subsets, but which may not satisfy revealed preference, the union of two sets may be strictly preferred to each one taken separately. A representation theorem is given which rationalizes such choice behavior as being as if the individual is uncertain about future tastes. IN MANY PROBLEMS of individual choice, the choice is made in more than one stage. At early stages, the individual makes decisions which will constrain the choices that are feasible later. In effect, these early choices amount to choice of a subset of items from which subsequent choice will be made. This paper concerns choice among such opportunity sets, where the individual has a desire for flexibility which is irrational if the individual knows what his subsequent preferences will be.

Finite horizon sequential decision problems with a temporal von NeumannMorgenstern criterion are analyzed. This criterion, as developed in [7], is a generalization of von Neumann-Morgenstern (expected) utility of the vector of rewards, wherein an individual's preferences concerning the timing of the resolution of uncertainty are taken into account. The preference theory underlying this criterion is reviewed and then extended in natural fashion to yield preferences for strategies in sequential decision problems. The main result is that value functions for sequential decision problems can be defined by a dynamic programming recursion using the functions which represent the original preferences, and these value functions represent the preferences defined on strategies. This permits citation of standard results from the dynamic programming literature, concerning the existence of (memoryless) strategies which are optimal with respect to the given preference relation.