Evolving choice sets: The effect of dynamic (vs. static) choice sets on preferences

Most decision-making research examines static choice sets, with fixed options presented all at once. In contrast, people often make decisions from dynamic choice sets, in which new alternatives arise during the decision process. We show that compared to a static choice set, a dynamic choice set can systematically affect preferences, even when the final choice is from an identical set of options. Moreover, dynamic presentation can have opposite effects on preferences. To explain these patterns we propose a unified theory based on perceived variance of the attribute distribution. When dynamic presentation increases the perceived variance of a focal attribute, preferences shift towards the option that is best on that attribute. In contrast, when dynamic presentation reduces perceived variance of a focal attribute, preferences shift towards the option that is best on a non-focal attribute. Five studies examine this proposal using asymmetrically dominated and compromise choice sets.