Conflict-mediated choice

Abstract

Research on behavioral decision making has demonstrated that preferences are affected by the set of options under consideration. Formal models offer an account of such choice-set effects on the basis of principles according to which the similarity of the options in the choice set has an effect on choice probabilities. Behavioral formulations are Tversky's (1972) elimination-by-aspects (EBA) model, based on the principle of sequential elimination, and Tversky and Simonson's (1993) componential context (CC) model, based on the principle of pairwise comparisons subject to loss aversion. While these principles are assumed to determine choice behavior, the conflict induced by the set of options under consideration is assumed to be merely a source of indeterminacy in choice behavior. This paper challenges past models by offering a behavioral account of choice-set effects according to which the effect of similarity on choice probabilities is mediated by conflict. A conflict-mediated choice (CMC) model is developed, its testable implications are derived, and its predictions are contrasted with those of the EBA model and the CC model. Specifically, it is described how, according to each of the three models, choice probabilities are affected by the similarity of the options in the choice set and how choice-set effects are moderated by the relative weight of the attributes along which the options are positioned. In two experimental studies, the CMC model offers an accurate account of observed choice-set effects and outperforms the alternative models.