Data-Snooping Biases in Tests of Financial Asset Pricing Models
We investigate the extent to which tests of financial asset pricing models may be biased by using properties of the data to construct the test statistics. Specifically, we focus on tests using returns to portfolios of common stock where portfolios are constructed by sorting on some empirically motivated characteristic of the securities such as market value of equity. We present both analytical calculations and Monte Carlo simulations that show the effects of this type of data-snooping to be substantial. Even when the sorting characteristic is only marginally correlated with individual security statistics, 5 percent tests based on sorted portfolio returns may reject with probability one under the null hypothesis. This bias is shown to worsen as the number of securities increases given a fixed number of portfolios, and as the number of portfolios decreases given a fixed number of securities. We provide an empirical example that illustrates the practical relevance of these biases.
|Date of creation:||Jun 1989|
|Date of revision:|
|Publication status:||published as The Review of Financial Studies, Vol. 3, No. 3, pp. 431-467, (1990).|
|Contact details of provider:|| Postal: National Bureau of Economic Research, 1050 Massachusetts Avenue Cambridge, MA 02138, U.S.A.|
Web page: http://www.nber.org
More information through EDIRC
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.:
- Shanken, Jay, 1985. "Multivariate tests of the zero-beta CAPM," Journal of Financial Economics, Elsevier, vol. 14(3), pages 327-348, September.
- Chen, Nai-Fu & Roll, Richard & Ross, Stephen A, 1986. "Economic Forces and the Stock Market," The Journal of Business, University of Chicago Press, vol. 59(3), pages 383-403, July.
- Kandel, Shmuel & Stambaugh, Robert F., 1987. "On correlations and inferences about mean-variance efficiency," Journal of Financial Economics, Elsevier, vol. 18(1), pages 61-90, March.
- MacKinlay, A. Craig, 1987. "On multivariate tests of the CAPM," Journal of Financial Economics, Elsevier, vol. 18(2), pages 341-371, June.
- Merton, Robert C., 1985. "On the current state of the stock market rationality hypothesis," Working papers 1717-85., Massachusetts Institute of Technology (MIT), Sloan School of Management.
- Brown, Philip & Kleidon, Allan W. & Marsh, Terry A., 1983. "New evidence on the nature of size-related anomalies in stock prices," Journal of Financial Economics, Elsevier, vol. 12(1), pages 33-56, June.
- Lehmann, Bruce N. & Modest, David M., 1988. "The empirical foundations of the arbitrage pricing theory," Journal of Financial Economics, Elsevier, vol. 21(2), pages 213-254, September.
- Gibbons, Michael R., 1982. "Multivariate tests of financial models : A new approach," Journal of Financial Economics, Elsevier, vol. 10(1), pages 3-27, March.
- Campbell, John, 1987.
"Stock Returns and the Term Structure,"
3207699, Harvard University Department of Economics.
- Chan, K C & Chen, Nai-Fu, 1988. " An Unconditional Asset-Pricing Test and the Role of Firm Size as an Instrumental Variable for Risk," Journal of Finance, American Finance Association, vol. 43(2), pages 309-25, June.
- Gibbons, Michael R & Ross, Stephen A & Shanken, Jay, 1989. "A Test of the Efficiency of a Given Portfolio," Econometrica, Econometric Society, vol. 57(5), pages 1121-52, September.
- Huberman, Gur & Kandel, Shmuel & Stambaugh, Robert F, 1987. " Mimicking Portfolios and Exact Arbitrage Pricing," Journal of Finance, American Finance Association, vol. 42(1), pages 1-9, March.
- Blume, Marshall E, 1970. "Portfolio Theory: A Step Toward Its Practical Application," The Journal of Business, University of Chicago Press, vol. 43(2), pages 152-73, April.
- Josef Lakonishok, Seymour Smidt, 1988. "Are Seasonal Anomalies Real? A Ninety-Year Perspective," Review of Financial Studies, Society for Financial Studies, vol. 1(4), pages 403-425.
- 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 607-36, May-June.
- Connor, Gregory & Korajczyk, Robert A., 1988. "Risk and return in an equilibrium APT : Application of a new test methodology," Journal of Financial Economics, Elsevier, vol. 21(2), pages 255-289, September.
- Chamberlain, Gary, 1983. "Funds, Factors, and Diversification in Arbitrage Pricing Models," Econometrica, Econometric Society, vol. 51(5), pages 1305-23, September.
- Huberman, Gur & Kandel, Shmuel, 1987. " Mean-Variance Spanning," Journal of Finance, American Finance Association, vol. 42(4), pages 873-88, September.
- Banz, Rolf W., 1981. "The relationship between return and market value of common stocks," Journal of Financial Economics, Elsevier, vol. 9(1), pages 3-18, March.
- Arne Sandström, 1987. "Asymptotic normality of linear functions of concomitants of order statistics," Metrika: International Journal for Theoretical and Applied Statistics, Springer, vol. 34(1), pages 129-142, December.
When requesting a correction, please mention this item's handle: RePEc:nbr:nberwo:3001. 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 references are entirely missing, you can add them using this form.