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Inference by Believers in the Law of Small Numbers

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Author Info
Matthew Rabin (University of California, Berkeley)
Abstract

Many people believe in the "Law of Small Numbers," exaggerating the degree to which a small sample resembles the population from which it is drawn. To model this, I assume that a person exaggerates the likelihood that a short sequence of i.i.d. signals resembles the long-run rate at which those signals are generated. Such a person believes in the "gambler's fallacy", thinking early draws of one signal increase the odds of next drawing other signals. When uncertain about the rate, the person over-infers from short sequences of signals, and is prone to think the rate is more extreme than it is. When the person makes inferences about the frequency at which rates are generated by different sources -- such as the distribution of talent among financial analysts -- based on few observations from each source, he tends to exaggerate how much variance there is in the rates. Hence, the model predicts that people may pay for financial advice from "experts" whose expertise is entirely illusory. Other economic applications are discussed.

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Paper provided by EconWPA in its series Method and Hist of Econ Thought with number 0012002.

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Length: 53 pages
Date of creation: 02 Jan 2001
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Handle: RePEc:wpa:wuwpmh:0012002

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B49 - Schools of Economic Thought and Methodology - - Economic Methodology - - - Other

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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.:
  1. Harrison Hong & Terence Lim & Jeremy C. Stein, 1998. "Bad News Travels Slowly: Size, Analyst Coverage and the Profitability of Momentum Strategies," NBER Working Papers 6553, National Bureau of Economic Research, Inc. [Downloadable!] (restricted)
  2. Matthew Rabin, 1998. "Psychology and Economics," Journal of Economic Literature, American Economic Association, vol. 36(1), pages 11-46, March. [Downloadable!] (restricted)
  3. Joel L. Schrag, 1999. "First Impressions Matter: A Model Of Confirmatory Bias," The Quarterly Journal of Economics, MIT Press, vol. 114(1), pages 37-82, February. [Downloadable!] (restricted)
  4. Keren, Gideon & Lewis, Charles, 1994. "The Two Fallacies of Gamblers: Type I and Type II," Organizational Behavior and Human Decision Processes, Elsevier, vol. 60(1), pages 75-89, October. [Downloadable!] (restricted)
  5. Camerer, Colin F, 1989. "Does the Basketball Market Believe in the 'Hot Hand'?," American Economic Review, American Economic Association, vol. 79(5), pages 1257-61, December. [Downloadable!] (restricted)
  6. Grether, David M, 1980. "Bayes Rule as a Descriptive Model: The Representativeness Heuristic," The Quarterly Journal of Economics, MIT Press, vol. 95(3), pages 537-57, November. [Downloadable!] (restricted)
  7. 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. [Downloadable!] (restricted)
  8. De Bondt, Werner F M & Thaler, Richard H, 1987. " Further Evidence on Investor Overreaction and Stock Market Seasonalit y," Journal of Finance, American Finance Association, vol. 42(3), pages 557-81, July. [Downloadable!] (restricted)
  9. Mark Walker & John Wooders, 2001. "Minimax Play at Wimbledon," American Economic Review, American Economic Association, vol. 91(5), pages 1521-1538, December. [Downloadable!] (restricted)
  10. Charles T. Clotfelter & Philip J. Cook, 1991. "The "Gambler's Fallacy" in Lottery Play," NBER Working Papers 3769, National Bureau of Economic Research, Inc. [Downloadable!] (restricted)
  11. Nicholas Barberis & Ming Huang & Tano Santos, 1999. "Prospect Theory and Asset Prices," NBER Working Papers 7220, National Bureau of Economic Research, Inc. [Downloadable!] (restricted)
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  1. Chan, Wesley & Frankel, Richard & Kothari, S.P., 2002. "Testing Behavioral Finance Theories Using Trends and Sequences in Financial Performance," Working papers 4375-02, Massachusetts Institute of Technology (MIT), Sloan School of Management. [Downloadable!]
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