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Selection bias and pseudo discoveries on the constancy of stock return anomalies

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Abstract

There are now a large and rapidly growing number of studies that test the constancy of stock return anomalies. In this study, we produce new and convincing evidence that the standard constancy test is heavily influenced by selection bias. Backed by a carefully designed Monte Carlo simulation, we show that selection bias predisposes the standard constancy test to reject the null by a factor of five to 12 times more than normally expected. Failure to recognize this bias can result in publication of the type of pseudo discoveries that Harvey (J Finance 72(4):1399–1440, 2017) warns about in his Presidential Address to the American Finance Association. We then describe the Quandt/Andrews test, a correct and unbiased test for anomalies and changes in anomalies, and apply it to test the constancy of 15 well-known stock return anomalies.

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Notes

  1. See also Harvey et al. (2016) and Harvey’s Keynote Address at the 2019 Annual Meeting of the Financial Management Association entitled “Fake Research” for more on statistical bias in financial research.

  2. See, for example, Jaffe et al. (1989), Jegadeesh and Titman (2001), Schwert (2003), Darrat et al. (2013), Chordia et al. (2014), McLean and Pontiff (2016), Bhattacharya et al. (2017), and Linnainmaa and Roberts (2018).

  3. See, for example, the momentum anomaly of Jegadeesh and Titman (1993), the accruals anomaly of Sloan (1996), and the investment anomaly of Cooper et al. (2008).

  4. Greenstone and Oyer (2000) also raise this fundamental and important concern in the context of testing for industry-specific calendar anomalies.

  5. Ten of the 15 anomalies we will later test for constancy are significant at the one percent level.

  6. It is not possible to test all subperiods only all possible subperiods. As a difference in means test, the Chow F-test requires two subperiods in which to calculate and then compare the means. We follow the standard approach, which is to start by testing a subperiod containing the first 15 percent of total observations against a subperiod containing the last 85 percent of total observations. Then continue by moving forward one month and re-doing the test. The final test is between the first 85 percent of total observations against the last 15 percent of total observations. The sequence of Chow F-statistics is thus only calculated between the first 15 percent and the last 15 percent of total monthly return observations. The value of 15 percent is known as the trimming parameter.

  7. The current Web address is http://mba.tuck.dartmouth.edu/pages/faculty/ken.french/data_library.html.

  8. We analyze the data with computer software by the R Project for Statistical Computing in conjunction with the strucchange package of Zeileis et al. (2002) and Zeileis et al. (2003).

  9. Robins and Smith (2016) bootstrap the five percent critical value of the supF-statistic and find that their bootstrapped critical value is equivalent to the five percent critical value in Andrews (1993, 2003).

  10. The supF-statistics in Figs. 2 and 3 and in Table 2 are corrected for heteroskedasticity and autocorrelation whereas the subperiods in Table 3 correspond to the month of the uncorrected supF-statistics. This is exactly the correct approach though because the exogenous subperiods are defined by minimum total RSS and this is not affected by heteroskedasticity and autocorrelation.

References

  • Andrews DWK (1991) Heteroskedasticity and autocorrelation consistent covariance matrix estimation. Econometrica 59(3):817–858

    Google Scholar 

  • Andrews DWK (1993) Tests for parameter instability and structural change with unknown change point. Econometrica 61(4):821–856

    Google Scholar 

  • Andrews DWK (2003) Tests for parameter instability and structural change with unknown change point: a corrigendum. Econometrica 71(1):395–397

    Google Scholar 

  • Andrews DWK, Ploberger W (1994) Optimal tests when a nuisance parameter is present only under the alternative. Econometrica 62(6):1383–1414

    Google Scholar 

  • Ang A, Hodrick RJ, Xing Y, Zhang X (2006) The cross-section of volatility and expected returns. J Finance 61(1):259–299

    Google Scholar 

  • Banz RW (1981) The relationship between return and market value of common stocks. J Financ Econ 9:3–18

    Google Scholar 

  • Basu S (1977) Investment performance of common stocks in relation to their price-earnings ratios: a test of the efficient market hypothesis. J Finance 32(3):663–682

    Google Scholar 

  • Bebchuk LA, Cohen A, Wang CC (2013) Learning and the disappearing association between governance and returns. J Financ Econ 108:323–348

    Google Scholar 

  • Ben-David D, Papell DH (1998) Slowdowns and meltdowns: Postwar growth evidence from 74 countries. Rev Econ Stat 80(4):561–571

    Google Scholar 

  • Bhattacharya D, Li WH, Sonaer G (2017) Has momentum lost its momentum? Rev Quant Financ Acc 48:191–218

    Google Scholar 

  • Chordia T, Subrahmanyam A, Tong Q (2014) Have capital market anomalies attenuated in the recent era of high liquidity and trading activity? J Acc Econ 58:41–58

    Google Scholar 

  • Cooper MJ, Gulen H, Schill MJ (2008) Asset growth and the cross-section of stock returns. J Finance 63(4):1609–1651

    Google Scholar 

  • Darrat AF, Li B, Chung R (2013) The other month effect: a re-examination of the “other January” anomaly. Rev Pac Basin Financ Mark Polic 16(2):1–23

    Google Scholar 

  • De Bondt WFM, Thaler R (1985) Does the stock market overreact? J Finance 40(3):793–805

    Google Scholar 

  • Fama EF, French KR (1992) The cross-section of expected stock returns. J Finance 47(2):427–465

    Google Scholar 

  • Fama EF, French KR (2016) Dissecting anomalies with a five-factor model. Rev Financ Stud 29(1):69–103

    Google Scholar 

  • Fama EF, MacBeth JD (1973) Risk, return, and equilibrium: empirical tests. J Polit Econ 81(3):607–636

    Google Scholar 

  • French KR (1980) Stock returns and the weekend effect. J Financ Econ 8:55–69

    Google Scholar 

  • Gibbons MR, Hess P (1981) Day of the week effects and asset returns. J Bus 54(4):579–596

    Google Scholar 

  • Greenstone M, Oyer P (2000) Are there sectoral anomalies too? The pitfalls of unreported multiple hypothesis testing and a simple solution. Rev Quant Financ Acc 15:37–55

    Google Scholar 

  • Hansen BE (1997) Approximate asymptotic P values for structural-change tests. J Bus Econ Stat 15(1):60–67

    Google Scholar 

  • Hansen BE (2001) The new econometrics of structural change: Dating breaks in U.S. labor productivity. J Econ Perspect 15(4):117–128

    Google Scholar 

  • Harvey CR (2017) Presidential address: the scientific outlook in financial economics. J Finance 72(4):1399–1440

    Google Scholar 

  • Harvey CR, Liu Y, Zhu H (2016)... and the cross-section of expected returns. Rev Financ Stud 29(1):5–68

    Google Scholar 

  • Haugen RA, Heins AJ (1975) Risk and the rate of return on financial assets: some old wine in new bottles. J Financ Quant Anal 10(5):775–784

    Google Scholar 

  • Holland PW (1986) Statistics and causal inference. J Am Stat Assoc 81(396):945–960

    Google Scholar 

  • Jaffe J, Keim DB, Westerfield R (1989) Earnings yields, market values, and stock returns. J Finance 44(1):135–148

    Google Scholar 

  • Jegadeesh N (1990) Evidence of predictable behavior of security returns. J Finance 45(3):881–898

    Google Scholar 

  • Jegadeesh N, Titman S (1993) Returns to buying winners and selling losers: implications for stock market efficiency. J Finance 48(1):65–91

    Google Scholar 

  • Jegadeesh N, Titman S (2001) Profitability of momentum strategies: an evaluation of alternative explanations. J Finance 56(2):699–720

    Google Scholar 

  • Lakonishok J, Shleifer A, Vishny RW (1994) Contrarian investment, extrapolation, and risk. J Finance 49(5):1541–1578

    Google Scholar 

  • Linnainmaa JT, Roberts MR (2018) The history of the cross section of stock returns. Rev Financ Stud 31(7):2606–2649

    Google Scholar 

  • McConnell MM, Perez-Quiros G (2000) Output fluctuations in the United States: what has changed since the early 1980’s? Am Econ Rev 90(5):1464–1476

    Google Scholar 

  • McLean RD, Pontiff J (2016) Does academic research destroy stock return predictability? J Finance 71(1):5–32

    Google Scholar 

  • Naranjo A, Nimalendran M, Ryngaert M (1998) Stock returns, dividend yields, and taxes. J Finance 53(6):2029–2057

    Google Scholar 

  • Newey WK, West KD (1987) A simple, positive semi-definite, heteroskedasticity and autocorrelation consistent covariance matrix. Econometrica 55(3):703–708

    Google Scholar 

  • Novy-Marx R (2013) The other side of value: the gross profitability premium. J Financ Econ 108:1–28

    Google Scholar 

  • Pontiff J, Woodgate A (2008) Share issuance and cross-sectional returns. J Finance 63(2):921–945

    Google Scholar 

  • Quandt RE (1958) The estimation of the parameters of a linear regression system obeying two separate regimes. J Am Stat Assoc 53(284):873–880

    Google Scholar 

  • Quandt RE (1960) Tests of the hypothesis that a linear regression system obeys two separate regimes. J Am Stat Assoc 55(290):324–330

    Google Scholar 

  • Robins RP, Smith GP (2016) No more weekend effect. Crit Finance Rev 5:417–424

    Google Scholar 

  • Schwert GW (2003) Anomalies and market efficiency. In: Constantinides G, Harris M, Stulz R (eds) Handbook of the economics of finance, chapter 15. Elsevier, Amsterdam, pp 937–972

    Google Scholar 

  • Sloan RG (1996) Do stock prices fully reflect information in accruals and cash flows about future earnings? Acc Rev 71(3):289–315

    Google Scholar 

  • Stock JH, Watson MW (1996) Evidence on structural instability in macroeconomic time series relations. J Bus Econ Stat 14(1):11–30

    Google Scholar 

  • Zeileis A, Leisch F, Hornik K, Kleiber C (2002) strucchange: an R package for testing for structural change in linear regression models. J Stat Softw 7(2):1–38

    Google Scholar 

  • Zeileis A, Kleiber C, Krämer W, Hornik K (2003) Testing and dating of structural changes in practice. Comput Stat Data Anal 44:109–123

    Google Scholar 

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Acknowledgements

We thank P. Richard Hahn, Cheng-Few Lee (Editor), Ivo Welch, an anonymous referee, and the participants at the 2018 Annual Meeting of the Southern Finance Association for their helpful comments and suggestions.

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Correspondence to Geoffrey Peter Smith.

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Robins, R.P., Smith, G.P. Selection bias and pseudo discoveries on the constancy of stock return anomalies. Rev Quant Finan Acc 55, 1407–1426 (2020). https://doi.org/10.1007/s11156-020-00878-w

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