Violations of conjoint independence in binary choices: The equate-to-differentiate interpretation

The studies described in the present paper extend the author s earlier work on testing the ‘‘independence condition’’ for decisions under risk to the ‘‘conjoint independence’’ for multi-attribute decisions. The ‘‘equate-to-differentiate’’ approach, which is proposed as a means by which weak dominance can be made applicable in more general cases in binary choice, is presented to account for the observed violations of independence. [Journal of Business 59 (1986) S251] transparency hypothesis concerning violations of the independence axiom is compared with the equate-to-differentiate hypothesis. The findings for various decision tasks favor the equate-to-differentiate explanation. The results support the claim that the violation of independence should be observed when the equate-to-differentiate strategy is caused to be changed by the experimental conditions applied, but not otherwise. 2002 Elsevier Science B.V. All rights reserved.