PREFERENCE REVERSALS - VIOLATIONS OF UNIDIMENSIONAL PROCEDURE INVARIANCE

Preference reversals have usually been explained by weighted additive models, in which different tasks give rise to different importance wei ghts for the stimulus attributes, resulting in contradictory trade-off s. This article presents a preference reversal of a more extreme natur e. Let (10, 5 Migr) denote living 10 years with a migraine for 5 days per week. Many participants preferred (10, 5 Migr) to (20, 5 Migr). Ho wever, when asked to equate these two options with a shorter period of good health, they usually demanded more healthy life years for (20, 5 Migr) than for (10, 5 Migr). This preference reversal within a single dimension cannot be explained by different importance weights and sug gests irrationalities at a more fundamental level. Most participants d id not change their responses after being confronted with their incons istencies.