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Aggregating experts’ opinions to select the winner of a competition

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  • Pablo Amorós

    (Universidad de Málaga)

Abstract

The opinions of a group of experts must be aggregated to determine the deserving winner of a competition. The procedure of aggregation is majoritarian if, whenever a majority of experts honestly believe that a contestant is the best, the given contestant is considered the deserving winner. The fact that an expert believes that a contestant is the best does not necessarily imply that he/she wants this contestant to win as, for example, he/she might be biased in favor of another contestant. A mechanism is thus needed to provide the appropriate incentives to the experts so that, in equilibrium, they choose the deserving winner. We show that if the aggregation procedure is majoritarian, such a mechanism exists only if the experts are totally impartial. This impossibility result is very strong as it does not depend on the concept of ordinal equilibrium. Moreover, it holds even if we replace majoritarianism by unanimity (whenever a contestant is honestly viewed as best by all experts, then that contestant is considered the deserving winner) and anonymity (changing the names of the experts with each opinion would not change the deserving winner).

Suggested Citation

  • Pablo Amorós, 2020. "Aggregating experts’ opinions to select the winner of a competition," International Journal of Game Theory, Springer;Game Theory Society, vol. 49(3), pages 833-849, September.
    • Handle: RePEc:spr:jogath:v:49:y:2020:i:3:d:10.1007_s00182-020-00712-6
    DOI: 10.1007/s00182-020-00712-6
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    References listed on IDEAS

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    1. Saijo, Tatsuyoshi, 1987. "On constant maskin monotonic social choice functions," Journal of Economic Theory, Elsevier, vol. 42(2), pages 382-386, August.
    2. List, Christian & Pettit, Philip, 2002. "Aggregating Sets of Judgments: An Impossibility Result," Economics and Philosophy, Cambridge University Press, vol. 18(1), pages 89-110, April.
    3. Feddersen, Timothy & Pesendorfer, Wolfgang, 1998. "Convicting the Innocent: The Inferiority of Unanimous Jury Verdicts under Strategic Voting," American Political Science Review, Cambridge University Press, vol. 92(1), pages 23-35, March.
    4. Vijay Krishna & John Morgan, 2001. "A Model of Expertise," The Quarterly Journal of Economics, President and Fellows of Harvard College, vol. 116(2), pages 747-775.
    5. Wolinsky, Asher, 2002. "Eliciting information from multiple experts," Games and Economic Behavior, Elsevier, vol. 41(1), pages 141-160, October.
    6. Gerardi, Dino & McLean, Richard & Postlewaite, Andrew, 2009. "Aggregation of expert opinions," Games and Economic Behavior, Elsevier, vol. 65(2), pages 339-371, March.
    7. Austen-Smith, David & Banks, Jeffrey S., 1996. "Information Aggregation, Rationality, and the Condorcet Jury Theorem," American Political Science Review, Cambridge University Press, vol. 90(1), pages 34-45, March.
    8. Mackenzie, Andrew, 2015. "Symmetry and impartial lotteries," Games and Economic Behavior, Elsevier, vol. 94(C), pages 15-28.
    9. Muller, Eitan & Satterthwaite, Mark A., 1977. "The equivalence of strong positive association and strategy-proofness," Journal of Economic Theory, Elsevier, vol. 14(2), pages 412-418, April.
    10. Duggan, John & Martinelli, Cesar, 2001. "A Bayesian Model of Voting in Juries," Games and Economic Behavior, Elsevier, vol. 37(2), pages 259-294, November.
    11. McLennan, Andrew, 1998. "Consequences of the Condorcet Jury Theorem for Beneficial Information Aggregation by Rational Agents," American Political Science Review, Cambridge University Press, vol. 92(2), pages 413-418, June.
    12. Ron Holzman & Hervé Moulin, 2013. "Impartial Nominations for a Prize," Econometrica, Econometric Society, vol. 81(1), pages 173-196, January.
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    More about this item

    Keywords

    Mechanism design; Social choice; Aggregation of experts’ opinions; Jury;
    All these keywords.

    JEL classification:

    • C72 - Mathematical and Quantitative Methods - - Game Theory and Bargaining Theory - - - Noncooperative Games
    • D71 - Microeconomics - - Analysis of Collective Decision-Making - - - Social Choice; Clubs; Committees; Associations
    • D78 - Microeconomics - - Analysis of Collective Decision-Making - - - Positive Analysis of Policy Formulation and Implementation

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