IDEAS home Printed from
MyIDEAS: Login to save this paper or follow this series

Overconfidence and market efficiency with heterogeneous agents

  • Diego Garcia
  • Francesco Sangiorgi
  • Branko Urosevic

We study financial markets in which both rational and overconfident agents coexist and make endogenous information acquisition decisions. We demonstrate the following irrelevance result: when a positive fraction of rational agents (endogeneously) decides to become informed in equilibrium, prices are set as if all investors were rational, and as a consequence the overconfidence bias does not a ect informational efficiency, price volatility, rational traders’ expected profits or their welfare. Intuitively, as overconfidence goes up, so does price infornativeness, which makes rational agents cut their information acquisition activities, effectively undoing the standard effect of more aggressive trading by the overconfident.

If you experience problems downloading a file, check if you have the proper application to view it first. In case of further problems read the IDEAS help page. Note that these files are not on the IDEAS site. Please be patient as the files may be large.

File URL:
File Function: Whole Paper
Download Restriction: no

Paper provided by Department of Economics and Business, Universitat Pompeu Fabra in its series Economics Working Papers with number 786.

in new window

Date of creation: Oct 2004
Date of revision:
Handle: RePEc:upf:upfgen:786
Contact details of provider: Web page:

References listed on IDEAS
Please report citation or reference errors to , or , if you are the registered author of the cited work, log in to your RePEc Author Service profile, click on "citations" and make appropriate adjustments.:

as in new window
  1. Markus Glaser & Martin Weber, 2007. "Overconfidence and trading volume," The Geneva Papers on Risk and Insurance Theory, Springer, vol. 32(1), pages 1-36, June.
  2. Simon Gervais & Terrance Odean, . "Learning To Be Overconfident," Rodney L. White Center for Financial Research Working Papers 05-97, Wharton School Rodney L. White Center for Financial Research.
  3. De Long, J Bradford, et al, 1991. "The Survival of Noise Traders in Financial Markets," The Journal of Business, University of Chicago Press, vol. 64(1), pages 1-19, January.
  4. Caballe, Jordi & Sakovics, Jozsef, 2003. "Speculating against an overconfident market," Journal of Financial Markets, Elsevier, vol. 6(2), pages 199-225, April.
  5. Antonio Bernardo & Ivo Welch, 2001. "On the Evolution of Overconfidence and Entrepreneurs," Yale School of Management Working Papers ysm211, Yale School of Management, revised 01 Nov 2003.
  6. J. Bradford De Long & Andrei Shleifer & Lawrence H. Summers & Robert J. Waldmann, . "Noise Trader Risk in Financial Markets," J. Bradford De Long's Working Papers _124, University of California at Berkeley, Economics Department.
  7. Benos, Alexandros V., 1998. "Aggressiveness and survival of overconfident traders," Journal of Financial Markets, Elsevier, vol. 1(3-4), pages 353-383, September.
  8. Shleifer, Andrei & Vishny, Robert W, 1997. " The Limits of Arbitrage," Journal of Finance, American Finance Association, vol. 52(1), pages 35-55, March.
  9. Sanford J Grossman & Joseph E Stiglitz, 1997. "On the Impossibility of Informationally Efficient Markets," Levine's Working Paper Archive 1908, David K. Levine.
  10. Admati, Anat R. & Pfleiderer, Paul, 1987. "Viable allocations of information in financial markets," Journal of Economic Theory, Elsevier, vol. 43(1), pages 76-115, October.
  11. Alan D. Morrison, 2004. "Competition and Information Production in Market Maker Models," Journal of Business Finance & Accounting, Wiley Blackwell, vol. 31(7-8), pages 1171-1190.
  12. Brad M. Barber & Terrance Odean, 2001. "Boys Will Be Boys: Gender, Overconfidence, And Common Stock Investment," The Quarterly Journal of Economics, MIT Press, vol. 116(1), pages 261-292, February.
  13. Jose A. Scheinkman & Wei Xiong, 2003. "Overconfidence and Speculative Bubbles," Journal of Political Economy, University of Chicago Press, vol. 111(6), pages 1183-1219, December.
  14. Shleifer, Andrei, 2000. "Inefficient Markets: An Introduction to Behavioral Finance," OUP Catalogue, Oxford University Press, number 9780198292272, July.
  15. Dubra, J., 1999. "Overconfidence in Search," Working Papers 99-10, C.V. Starr Center for Applied Economics, New York University.
  16. Hirshleifer, David & Luo, Guo Ying, 2001. "On the survival of overconfident traders in a competitive securities market," Journal of Financial Markets, Elsevier, vol. 4(1), pages 73-84, January.
  17. Gadi Barlevy & Pietro Veronesi, . "Information Acquisition in Financial Markets," CRSP working papers 360, Center for Research in Security Prices, Graduate School of Business, University of Chicago.
  18. Hellwig, Martin F., 1980. "On the aggregation of information in competitive markets," Journal of Economic Theory, Elsevier, vol. 22(3), pages 477-498, June.
  19. Diamond, Douglas W, 1985. " Optimal Release of Information by Firms," Journal of Finance, American Finance Association, vol. 40(4), pages 1071-94, September.
  20. Kyle, Albert S, 1985. "Continuous Auctions and Insider Trading," Econometrica, Econometric Society, vol. 53(6), pages 1315-35, November.
  21. Verrecchia, Robert E, 1982. "Information Acquisition in a Noisy Rational Expectations Economy," Econometrica, Econometric Society, vol. 50(6), pages 1415-30, November.
  22. KENT D. DANIEL & David Hirshleifer & AVANIDHAR SUBRAHMANYAM, 2004. "A Theory of Overconfidence, Self-Attribution, and Security Market Under- and Over-reactions," Finance 0412006, EconWPA.
  23. Admati, Anat R. & Pfleiderer, Paul, 1986. "A monopolistic market for information," Journal of Economic Theory, Elsevier, vol. 39(2), pages 400-438, August.
Full references (including those not matched with items on IDEAS)

This item is not listed on Wikipedia, on a reading list or among the top items on IDEAS.

When requesting a correction, please mention this item's handle: RePEc:upf:upfgen:786. 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: ()

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 references are entirely missing, you can add them using this form.

If the full references list an item that is present in RePEc, but the system did not link 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 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.

This information is provided to you by IDEAS at the Research Division of the Federal Reserve Bank of St. Louis using RePEc data.