IDEAS home Printed from
MyIDEAS: Login to save this article or follow this journal

Adaptive behavior leads to under-diversification

  • Zion, Uri Ben
  • Erev, Ido
  • Haruvy, Ernan
  • Shavit, Tal

In a given period, a diversified fund, by virtue of being a weighted average, will perform somewhere in the middle range of its components' respective performances. This means that adaptive investors who look to the past to adjust expectations about future returns will shun diversified funds. That is, adaptive reaction to feedback implies under-diversification when the investor gets complete feedback on the performance of the diversified fund as well as its components in a given period. Three laboratory experiments and one quasi field experiment explore this possibility and its implications. We find that the availability of complete feedback drastically reduces diversification. Under-diversification is observed even when the decision makers receive a complete description of the payoff distributions and when under-diversification lowers expected return.

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:
Download Restriction: Full text for ScienceDirect subscribers only

As the access to this document is restricted, you may want to look for a different version under "Related research" (further below) or search for a different version of it.

Article provided by Elsevier in its journal Journal of Economic Psychology.

Volume (Year): 31 (2010)
Issue (Month): 6 (December)
Pages: 985-995

in new window

Handle: RePEc:eee:joepsy:v:31:y:2010:i:6:p:985-995
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. Kahneman, Daniel & Tversky, Amos, 1979. "Prospect Theory: An Analysis of Decision under Risk," Econometrica, Econometric Society, vol. 47(2), pages 263-91, March.
  2. James Choi & David Laibson & Brigitte Madrian & Andrew Metrick, 2007. "Reinforcement Learning and Savings Behavior," Yale School of Management Working Papers amz2657, Yale School of Management, revised 01 Mar 2009.
  3. De Bondt, Werner F M & Thaler, Richard, 1985. " Does the Stock Market Overreact?," Journal of Finance, American Finance Association, vol. 40(3), pages 793-805, July.
  4. Ido Erev & Eyal Ert & Alvin E. Roth, 2010. "A Choice Prediction Competition for Market Entry Games: An Introduction," Games, MDPI, Open Access Journal, vol. 1(2), pages 117-136, May.
  5. Chevalier, Judith & Ellison, Glenn, 1997. "Risk Taking by Mutual Funds as a Response to Incentives," Journal of Political Economy, University of Chicago Press, vol. 105(6), pages 1167-1200, December.
  6. Valery Polkovnichenko, 2005. "Household Portfolio Diversification: A Case for Rank-Dependent Preferences," Review of Financial Studies, Society for Financial Studies, vol. 18(4), pages 1467-1502.
  7. Fudenberg, Drew & Levine, David, 1998. "Learning in games," European Economic Review, Elsevier, vol. 42(3-5), pages 631-639, May.
  8. Terrance Odean, 1999. "Do Investors Trade Too Much?," American Economic Review, American Economic Association, vol. 89(5), pages 1279-1298, December.
  9. Ann-Renée Blais & Elke U. Weber, 2006. "A Domain-Specific Risk-Taking (DOSPERT)Scale for Adult Populations," CIRANO Working Papers 2006s-24, CIRANO.
  10. Blume, Marshall E & Friend, Irwin, 1975. "The Asset Structure of Individual Portfolios and Some Implications for Utility Functions," Journal of Finance, American Finance Association, vol. 30(2), pages 585-603, May.
  11. Kelly, Morgan, 1995. "All their eggs in one basket: Portfolio diversification of US households," Journal of Economic Behavior & Organization, Elsevier, vol. 27(1), pages 87-96, June.
  12. De Bondt, Werner F M & Thaler, Richard H, 1990. "Do Security Analysts Overreact?," American Economic Review, American Economic Association, vol. 80(2), pages 52-57, May.
  13. Drew Fudenberg & David K. Levine, 1996. "The Theory of Learning in Games," Levine's Working Paper Archive 624, David K. Levine.
  14. Brit Grosskopf & Ido Erev & Eldad Yechiam, 2006. "Foregone with the Wind: Indirect Payoff Information and its Implications for Choice," International Journal of Game Theory, Springer, vol. 34(2), pages 285-302, August.
  15. Ippolito, Richard A, 1992. "Consumer Reaction to Measures of Poor Quality: Evidence from the Mutual Fund Industry," Journal of Law and Economics, University of Chicago Press, vol. 35(1), pages 45-70, April.
  16. Statman, Meir, 1987. "How Many Stocks Make a Diversified Portfolio?," Journal of Financial and Quantitative Analysis, Cambridge University Press, vol. 22(03), pages 353-363, September.
  17. Erik R. Sirri & Peter Tufano, 1998. "Costly Search and Mutual Fund Flows," Journal of Finance, American Finance Association, vol. 53(5), pages 1589-1622, October.
  18. Ann-Renée Blais & Elke U. Weber, 2006. "A Domain-Specific Risk-Taking (DOSPERT) scale for adult populations," Judgment and Decision Making, Society for Judgment and Decision Making, vol. 1, pages 33-47, July.
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:eee:joepsy:v:31:y:2010:i:6:p:985-995. 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: (Zhang, Lei)

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.