IDEAS home Printed from https://ideas.repec.org/p/cwl/cwldpp/1552.html
   My bibliography  Save this paper

Informational Herding and Optimal Experimentation

Author

Listed:
  • Lones Smith

    (Dept. of Economics, University of Michigan)

  • Peter Norman Sorensen

    () (Department of Economics, University of Copenhagen)

Abstract

We show that far from capturing a formally new phenomenon, informational herding is really a special case of single-person experimentation -- and 'bad herds' the typical failure of complete learning. We then analyze the analogous team equilibrium, where individuals maximize the present discounted welfare of posterity. To do so, we generalize Gittins indices to our non-bandit learning problem, and thereby characterize when contrarian behaviour arises: (i) While herds are still constrained efficient, they arise for a strictly smaller belief set. (ii) A log-concave log-likelihood ratio density robustly ensures that individuals should lean more against their myopic preference for an action the more popular it becomes.

Suggested Citation

  • Lones Smith & Peter Norman Sorensen, 2006. "Informational Herding and Optimal Experimentation," Cowles Foundation Discussion Papers 1552, Cowles Foundation for Research in Economics, Yale University.
    • Handle: RePEc:cwl:cwldpp:1552
    as

    Download full text from publisher

    File URL: https://cowles.yale.edu/sites/default/files/files/pub/d15/d1552.pdf
    Download Restriction: no

    Other versions of this item:

    References listed on IDEAS

    as
    1. Lones Smith & Peter Sorensen, 2000. "Pathological Outcomes of Observational Learning," Econometrica, Econometric Society, vol. 68(2), pages 371-398, March.
    2. Philippe Aghion & Patrick Bolton & Christopher Harris & Bruno Jullien, 1991. "Optimal Learning by Experimentation," Review of Economic Studies, Oxford University Press, vol. 58(4), pages 621-654.
    3. Matthew Doyle, 2010. "Informational externalities, strategic delay, and optimal investment subsidies," Canadian Journal of Economics, Canadian Economics Association, vol. 43(3), pages 941-966, August.
    4. Chamley, Christophe & Gale, Douglas, 1994. "Information Revelation and Strategic Delay in a Model of Investment," Econometrica, Econometric Society, vol. 62(5), pages 1065-1085, September.
    5. James Dow, 1991. "Search Decisions with Limited Memory," Review of Economic Studies, Oxford University Press, vol. 58(1), pages 1-14.
    6. Rothschild, Michael, 1974. "A two-armed bandit theory of market pricing," Journal of Economic Theory, Elsevier, vol. 9(2), pages 185-202, October.
    7. McLennan, Andrew, 1984. "Price dispersion and incomplete learning in the long run," Journal of Economic Dynamics and Control, Elsevier, vol. 7(3), pages 331-347, September.
    8. Amir, Rabah, 1996. "Sensitivity analysis of multisector optimal economic dynamics," Journal of Mathematical Economics, Elsevier, vol. 25(1), pages 123-141.
    9. Xavier Vives, 1993. "How Fast do Rational Agents Learn?," Review of Economic Studies, Oxford University Press, vol. 60(2), pages 329-347.
    10. Sgroi, Daniel, 2002. "Optimizing Information in the Herd: Guinea Pigs, Profits, and Welfare," Games and Economic Behavior, Elsevier, vol. 39(1), pages 137-166, April.
    11. Bikhchandani, Sushil & Hirshleifer, David & Welch, Ivo, 1992. "A Theory of Fads, Fashion, Custom, and Cultural Change in Informational Cascades," Journal of Political Economy, University of Chicago Press, vol. 100(5), pages 992-1026, October.
    12. Burdett, Kenneth, 1996. "Truncated means and variances," Economics Letters, Elsevier, vol. 52(3), pages 263-267, September.
    13. Abhijit V. Banerjee, 1992. "A Simple Model of Herd Behavior," The Quarterly Journal of Economics, Oxford University Press, vol. 107(3), pages 797-817.
    Full references (including those not matched with items on IDEAS)

    Citations

    Citations are extracted by the CitEc Project, subscribe to its RSS feed for this item.
    as


    Cited by:

    1. Alessandro Lizzeri & Marciano Siniscalchi, 2008. "Parental Guidance and Supervised Learning," The Quarterly Journal of Economics, Oxford University Press, vol. 123(3), pages 1161-1195.
    2. Jacob K. Goeree & Thomas R. Palfrey & Brian W. Rogers & Richard D. McKelvey, 2007. "Self-Correcting Information Cascades," Review of Economic Studies, Oxford University Press, vol. 74(3), pages 733-762.
    3. Gleason, Kimberly C. & Mathur, Ike & Peterson, Mark A., 2004. "Analysis of intraday herding behavior among the sector ETFs," Journal of Empirical Finance, Elsevier, vol. 11(5), pages 681-694, December.
    4. S. Ali & Navin Kartik, 2012. "Herding with collective preferences," Economic Theory, Springer;Society for the Advancement of Economic Theory (SAET), vol. 51(3), pages 601-626, November.
    5. Christos Koulovatianos & Leonard J. Mirman & Marc Santugini, 2006. "Investment in a Monopoly with Bayesian Learning," Vienna Economics Papers 0603, University of Vienna, Department of Economics.
    6. Matthew Doyle, 2010. "Informational externalities, strategic delay, and optimal investment subsidies," Canadian Journal of Economics, Canadian Economics Association, vol. 43(3), pages 941-966, August.

    More about this item

    Keywords

    Bayesian learning; value function; herding; experimentation; log concavity; Gittins index; team equilibrium;

    JEL classification:

    • D83 - Microeconomics - - Information, Knowledge, and Uncertainty - - - Search; Learning; Information and Knowledge; Communication; Belief; Unawareness

    NEP fields

    This paper has been announced in the following NEP Reports:

    Statistics

    Access and download statistics

    Corrections

    All material on this site has been provided by the respective publishers and authors. You can help correct errors and omissions. When requesting a correction, please mention this item's handle: RePEc:cwl:cwldpp:1552. See general information about how to correct material in RePEc.

    For technical questions regarding this item, or to correct its authors, title, abstract, bibliographic or download information, contact: (Matthew Regan). General contact details of provider: http://edirc.repec.org/data/cowleus.html .

    If you have authored this item and are not yet registered with RePEc, we encourage you to do it here. This allows to link your profile to this item. It also allows you to accept potential citations to this item that we are uncertain about.

    If CitEc recognized a reference but did not link an item in RePEc to it, you can help with this form .

    If you know of missing items citing this one, you can help us creating those links by adding the relevant references in the same way as above, for each refering item. If you are a registered author of this item, you may also want to check the "citations" tab in your RePEc Author Service profile, as there may be some citations waiting for confirmation.

    Please note that corrections may take a couple of weeks to filter through the various RePEc services.

    IDEAS is a RePEc service hosted by the Research Division of the Federal Reserve Bank of St. Louis . RePEc uses bibliographic data supplied by the respective publishers.