Animals' Choices over Uncertain Outcomes: Further Experimental Results
The betweenness axiom of expected utility theory, which is not required under several nonexpected utility formulations, is examined. Choices are checked for independence axiom violations in the Allais direction and for fanning out in little explored areas of the unit probability triangle, as predicted by Machina's hypothesis II. The data show Allais-type violations of the independence axiom, systematic failure of the fanning out hypothesis in the northwest portion of the unit probability triangle, and consistent violations of the betweenness axiom in favor of folded orderings. Results are related to findings from human choice experiments exploring similar phenomena. Copyright 1991 by Royal Economic Society.