Judgment and Decision Making (Apr 2010)
Decisions by coin toss
Abstract
In many situations of indeterminacy, where people agree that no decisive arguments favor one alternative to another, they are still strongly opposed to resolving the dilemma by a coin toss. The robustness of this judgment-decision discrepancy is demonstrated in several experiments, where factors like the importance of consequences, similarity of alternatives, conflicts of opinion, outcome certainty, type of randomizer, and fairness considerations are systematically explored. Coin toss is particularly inappropriate in cases of life and death, even when participants agree that the protagonists should have the same chance of being saved. Using a randomizer may seem to conflict with traditional ideas about argument-based rationality and personal responsibility of the decision maker. Moreover, a concrete randomizer like a coin appears more repulsive than the abstract principle of using a random device. Concrete randomizers may, however, be admissible to counteract potential partiality. Implications of the aversion to use randomizers, even under circumstances in which there are compelling reasons to do so, are briefly discussed.
