Examining Models of Nondominated Decoy Effects across Judgment and Choice.

Three experiments explored cognitive models of inferior, compromise, and phantom decoy effects in both judgment and choice. Participants made judgments of attractiveness, justifiability, and evaluation anxiety associated with each alternative in the set, along with judgments of the attractiveness of each alternative's dimensional values. In another session, they also chose the alternative they most preferred. Results were analyzed in terms of the degree to which decoy effects reflected shifts in dimensional values or reflected emergent values based on relationships with other alternatives in the set. Both emergent-value and value-shift models of inferior decoy effects were supported, but only the emergent-value model of compromise decoy effects was supported. Results for the phantom decoy indicated that this effect was choice-based and did not occur in judgment. Thus, although decoy effects were largely similar in choice and judgment, they also differed in important ways. Copyright 2000 Academic Press.