A New Experimental Study

Here’s a paper that uses experiments to understand popular attitudes towards coin tossing–

“Decisions by coin toss: Inappropriate but fair” by Gideon Keren & Karl Teigen. Judgment and Decision Making, April 2010, Pages 83-101.

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.

4 Responses

  1. The finding about support for the use of “a random device” but aversion toward flipping a coin and other specific devices is interesting, but the interpretation that this indicates that

    people seem to appreciate the usefulness of a random procedure, on an abstract level, to solve a problem of indeterminacy, but experience problems with applying a concrete instantiation of this principle

    seems premature.

    A simple alternative interpretation of the observed results would be an aversion toward ad-hoc, uninstitutionalized, unverifiable decision making devices. (All the devices suggested had the appearance of having been improvised.) Aversion toward such devices could be justified on the grounds that they may be open to manipulation and are not subject to later auditing.

    It is quite possible that support for using “a special-purpose device, designed and certified for use for scarce resource allocation, which emits at random one of several differently marked tokens” would be at levels similar to those expressed for the use of “a random device”.


  2. One more thing (possibly related to my first comment) – the authors mention that the custom of using a coin flip to determine a winner in a tied soccer match was replaced by penalty kicks. It is interesting to note that the NBA deliberately introduced randomness into the draft process, first using a coin flip and then through more elaborate devices.


  3. They call it ‘experiments’, but I’d say it’s no more than public opinion polling. (sorry, can’t afford to buy the paper; but I can guess what’s in it).

    This is a tricky call for us advocates of lottery-choice (l-c). In suveys folk say they don’t like it, especially for life-and-death choices amongst small numbers. Some use this to ‘prove’ that l-c is a Bad Thing eg for university places. Elster goes so far as to suggest difficult child custody cases could be fixed by l-c, but in secret by the judge, who then gives a ‘rational’ explanation for his choice.

    Details in my forthcoming book ‘Lotteries for Education’ (plug! plug!), which also includes a lovely opinion polling example where parents were led to an understanding of why l-c might not be such a bad thing for school place (seat) choice,


  4. Conall, I had no problem downloading the paper for free: pdf, html.

    I don’t think that the evidence shows clearly that people don’t like lottery-choice. Experiment 8 in the paper shows that people have no problem with a random choice in principle (in appropriate cases). I argue that the aversion toward decision by “coin toss” may be simply due to the appearance of haphazardness of the procedure. People may very well be willing to use an appropriately designed, verified and sanctioned randomization device to make choices.


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