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Aggregation of Expert Opinions

Author

Listed:
  • Dino Gerardi

    (Department of Economics, Yale University)

  • Richard McLean

    (Department of Economics, Rutgers University)

  • Andrew Postlewaite

    (Department of Economics, University of Pennsylvania)

Abstract

Conflicts of interest arise between a decision maker and agents who have information pertinent to the problem because of differences in their preferences over outcomes. We show how the decision maker can extract the information by distorting the decisions that will be taken, and show that only slight distortions will be necessary when agents are informationally small. We further show that as the number of informed agents becomes large the necessary distortion goes to zero. We argue that the particular mechanisms analyzed are substantially less demanding informationally than those typically employed in implementation and virtual implementation. In particular, the equilibria we analyze are conditionally dominant strategy in a precise sense. Further, the mechanisms are immune to manipulation by small groups of agents.

Suggested Citation

  • Dino Gerardi & Richard McLean & Andrew Postlewaite, 2005. "Aggregation of Expert Opinions," PIER Working Paper Archive 05-016, Penn Institute for Economic Research, Department of Economics, University of Pennsylvania.
    • Handle: RePEc:pen:papers:05-016
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    References listed on IDEAS

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    Citations

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    Cited by:

    1. Tilman Klumpp, 2007. "Communication in financial markets with several informed traders," Economic Theory, Springer;Society for the Advancement of Economic Theory (SAET), vol. 33(3), pages 437-456, December.
    2. Jackson, Matthew O. & Tan, Xu, 2013. "Deliberation, disclosure of information, and voting," Journal of Economic Theory, Elsevier, vol. 148(1), pages 2-30.
    3. Pablo Amorós, 2013. "Picking the winners," International Journal of Game Theory, Springer;Game Theory Society, vol. 42(4), pages 845-865, November.
    4. Irene Valsecchi, 2013. "The expert problem: a survey," Economics of Governance, Springer, vol. 14(4), pages 303-331, November.
    5. Tombazos, Christis G. & Dobra, Matthew, 2014. "Formulating research policy on expert advice," European Economic Review, Elsevier, vol. 72(C), pages 166-181.
    6. Casamatta, Catherine & Haritchabalet, Carole, 2007. "Experience, screening and syndication in venture capital investments," Journal of Financial Intermediation, Elsevier, vol. 16(3), pages 368-398, July.
    7. Chen, Yi-Chun & Mueller-Frank, Manuel & Pai, Mallesh M., 2022. "Continuous implementation with direct revelation mechanisms," Journal of Economic Theory, Elsevier, vol. 201(C).
    8. 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.
    9. Amorós, Pablo, 2023. "Evaluation and strategic manipulation," Journal of Mathematical Economics, Elsevier, vol. 106(C).
    10. Carl Heese & Stephan Lauermann, 2019. "Persuasion and Information Aggregation in Large Elections," CRC TR 224 Discussion Paper Series crctr224_2019_128, University of Bonn and University of Mannheim, Germany.
    11. Carl Heese & Stephan Lauermann, 2021. "Persuasion and Information Aggregation in Elections," ECONtribute Discussion Papers Series 112, University of Bonn and University of Cologne, Germany.
    12. Deimen, Inga & Ketelaar, Felix & Le Quement, Mark T., 2015. "Consistency and communication in committees," Journal of Economic Theory, Elsevier, vol. 160(C), pages 24-35.
    13. Elisabeth Schulte, 2010. "Information aggregation and preference heterogeneity in committees," Theory and Decision, Springer, vol. 69(1), pages 97-118, July.
    14. Elisabeth Schulte, 2012. "Communication in committees: who should listen?," Public Choice, Springer, vol. 150(1), pages 97-117, January.
    15. Dezsö Szalay & Ramon Arean, 2005. "Communicating with a Team of Experts," Cahiers de Recherches Economiques du Département d'économie 05.12, Université de Lausanne, Faculté des HEC, Département d’économie.
    16. repec:cte:werepe:we081207 is not listed on IDEAS
    17. Torun Dewan & Andrea Galeotti & Christian Ghiglino & Francesco Squintani, 2015. "Information aggregation and optimal structure of the executive," LSE Research Online Documents on Economics 59632, London School of Economics and Political Science, LSE Library.
    18. Feddersen, Timothy & Gradwohl, Ronen, 2020. "Decentralized advice," European Journal of Political Economy, Elsevier, vol. 63(C).
    19. M. Ferrara & F. Lamperti & R. Mavilia, 2016. "Looking for best performers: a pilot study towards the evaluation of science parks," Scientometrics, Springer;Akadémiai Kiadó, vol. 106(2), pages 717-750, February.
    20. De Moragas, Antoni-Italo, 2020. "When consensus hurts: experts' advice and electoral support," MPRA Paper 114800, University Library of Munich, Germany.
    21. Pablo Amorós, 2017. "The problem of aggregating experts' opinions to select the winner of a competition," Working Papers 2017-04, Universidad de Málaga, Department of Economic Theory, Málaga Economic Theory Research Center.
    22. Axel Niemeyer & Justus Preusser, 2024. "Optimal Allocation with Peer Information," Papers 2410.08954, arXiv.org.

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    More about this item

    Keywords

    Information aggregation; Asymmetric information; Cheap talk; Experts;
    All these keywords.

    JEL classification:

    • D7 - Microeconomics - - Analysis of Collective Decision-Making
    • D8 - Microeconomics - - Information, Knowledge, and Uncertainty

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