On the Spurious Correlation Between Sample Betas and Mean Returns
Cornerstone asset pricing models, such as capital asset pricing model (CAPM) and arbitrage pricing theory (APT), yield theoretical predictions about the relationship between expected returns and exposure to systematic risk, as measured by beta(s). Numerous studies have investigated the empirical validity of these models. We show that even if no relationship holds between true expected returns and betas in the population, the existence of low-probability extreme outcomes induces a spurious correlation between the sample means and the sample betas. Moreover, the magnitude of this purely spurious correlation is similar to the empirically documented correlation, and the regression slopes and intercepts are very similar as well. This result does not necessarily constitute evidence against the theoretical asset pricing models, but it does shed new light on previous empirical results, and it points to an issue that should be carefully considered in the empirical testing of these models. The analysis points to the dangers of relying on simple least squares regression for drawing conclusions about the validity of equilibrium pricing models.
Volume (Year): 19 (2012)
Issue (Month): 4 (September)
|Contact details of provider:|| Web page: http://www.tandfonline.com/RAMF20|
|Order Information:||Web: http://www.tandfonline.com/pricing/journal/RAMF20|
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.:
- Michael C. Jensen, 1968. "The Performance Of Mutual Funds In The Period 1945–1964," Journal of Finance, American Finance Association, vol. 23(2), pages 389-416, 05.
- Atkins, Allen B & Dyl, Edward A, 1997. " Transactions Costs and Holding Periods for Common Stocks," Journal of Finance, American Finance Association, vol. 52(1), pages 309-325, March.
- Nielsen, Lars Tyge, 1990. "Existence of equilibrium in CAPM," Journal of Economic Theory, Elsevier, vol. 52(1), pages 223-231, October.
- Kleibergen, Frank, 2009. "Tests of risk premia in linear factor models," Journal of Econometrics, Elsevier, vol. 149(2), pages 149-173, April.
- Levhari, David & Levy, Haim, 1977. "The Capital Asset Pricing Model and the Investment Horizon," The Review of Economics and Statistics, MIT Press, vol. 59(1), pages 92-104, February.
- Handa, Puneet & Kothari, S. P. & Wasley, Charles, 1989. "The relation between the return interval and betas : Implications for the size effect," Journal of Financial Economics, Elsevier, vol. 23(1), pages 79-100, June.
- John Lintner, 1965. "Security Prices, Risk, And Maximal Gains From Diversification," Journal of Finance, American Finance Association, vol. 20(4), pages 587-615, December.
- Moshe Levy & Richard Roll, 2010. "The Market Portfolio May Be Mean/Variance Efficient After All," Review of Financial Studies, Society for Financial Studies, vol. 23(6), pages 2464-2491, June.
- Fama, Eugene F & MacBeth, James D, 1973. "Risk, Return, and Equilibrium: Empirical Tests," Journal of Political Economy, University of Chicago Press, vol. 81(3), pages 607-636, May-June.
- Ross, Stephen A., 1976.
"The arbitrage theory of capital asset pricing,"
Journal of Economic Theory,
Elsevier, vol. 13(3), pages 341-360, December.
- Stephen A. Ross, "undated". "The Arbitrage Theory of Capital Asset Pricing," Rodney L. White Center for Financial Research Working Papers 02-73, Wharton School Rodney L. White Center for Financial Research.
- Stephen A. Ross, "undated". "The Arbitrage Theory of Capital Asset Pricing," Rodney L. White Center for Financial Research Working Papers 2-73, Wharton School Rodney L. White Center for Financial Research.
- Levy, Haim & Schwarz, Gideon, 1997. "Correlation and the time interval over which the variables are measured," Journal of Econometrics, Elsevier, vol. 76(1-2), pages 341-350.
- Levy, Moshe, 2007. "Conditions for a CAPM equilibrium with positive prices," Journal of Economic Theory, Elsevier, vol. 137(1), pages 404-415, November.
- Roll, Richard, 1977. "A critique of the asset pricing theory's tests Part I: On past and potential testability of the theory," Journal of Financial Economics, Elsevier, vol. 4(2), pages 129-176, March.
- Haim Levy & Ilan Guttman & Isabel Tkatch, 2001. "Regression, Correlation, and the Time Interval: Additive-Multiplicative Framework," Management Science, INFORMS, vol. 47(8), pages 1150-1159, August.
- Roll, Richard & Ross, Stephen A, 1994. " On the Cross-sectional Relation between Expected Returns and Betas," Journal of Finance, American Finance Association, vol. 49(1), pages 101-121, March.
- William F. Sharpe, 1964. "Capital Asset Prices: A Theory Of Market Equilibrium Under Conditions Of Risk," Journal of Finance, American Finance Association, vol. 19(3), pages 425-442, 09.
- Eugene F. Fama & Kenneth R. French, 2004. "The Capital Asset Pricing Model: Theory and Evidence," Journal of Economic Perspectives, American Economic Association, vol. 18(3), pages 25-46, Summer.
- Kevin Fergusson & Eckhard Platen, 2006.
"On the Distributional Characterization of Daily Log-Returns of a World Stock Index,"
Applied Mathematical Finance,
Taylor & Francis Journals, vol. 13(1), pages 19-38.
- Kevin Fergusson & Eckhard Platen, 2005. "On the Distributional Characterization of Log-returns of a World Stock Index," Research Paper Series 153, Quantitative Finance Research Centre, University of Technology, Sydney.
- Levy, Haim, 1978. "Equilibrium in an Imperfect Market: A Constraint on the Number of Securities in the Portfolio," American Economic Review, American Economic Association, vol. 68(4), pages 643-658, September.
- Black, Fischer, 1972. "Capital Market Equilibrium with Restricted Borrowing," The Journal of Business, University of Chicago Press, vol. 45(3), pages 444-455, July.
When requesting a correction, please mention this item's handle: RePEc:taf:apmtfi:v:19:y:2012:i:4:p:341-360. 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: (Michael McNulty)
If references are entirely missing, you can add them using this form.