IDEAS home Printed from https://ideas.repec.org/p/nbr/nberwo/0994.html
   My bibliography  Save this paper

Do We Really Know That Financial Markets Are Efficient?

Author

Listed:
  • Lawrence H. Summers

Abstract

This paper examines the power of statistical tests commonly used to examine the efficiency of speculative markets. It shows that for markets with "long horizons" such as the stock markets, or the market for long term bonds, these tests have very low power. Market valuations can differ substantially and persistently from the rational expectation of the present value of cash flows without leaving statistically discernible traces in the pattern of ex-post returns. This observation also suggests that speculation is unlikely to insure rational valuations, since similar problems of identification plague both financial economists and would-be speculators.

Suggested Citation

  • Lawrence H. Summers, 1982. "Do We Really Know That Financial Markets Are Efficient?," NBER Working Papers 0994, National Bureau of Economic Research, Inc.
  • Handle: RePEc:nbr:nberwo:0994
    Note: EFG PE
    as

    Download full text from publisher

    File URL: http://www.nber.org/papers/w0994.pdf
    Download Restriction: no
    ---><---

    References listed on IDEAS

    as
    1. Shiller, Robert J, 1981. "Do Stock Prices Move Too Much to be Justified by Subsequent Changes in Dividends?," American Economic Review, American Economic Association, vol. 71(3), pages 421-436, June.
    2. David S. Jones & V. Vance Roley, 1982. "Rational Expectations, the Expectations Hypothesis, and Treasury Bill Yields: An Econometric Analysis," NBER Working Papers 0869, National Bureau of Economic Research, Inc.
    3. Friedman, Benjamin M., 1979. "Optimal expectations and the extreme information assumptions of `rational expectations' macromodels," Journal of Monetary Economics, Elsevier, vol. 5(1), pages 23-41, January.
    4. Olivier J. Blanchard & Mark W. Watson, 1982. "Bubbles, Rational Expectations and Financial Markets," NBER Working Papers 0945, National Bureau of Economic Research, Inc.
    5. Jensen, Michael C., 1978. "Some anomalous evidence regarding market efficiency," Journal of Financial Economics, Elsevier, vol. 6(2-3), pages 95-101.
    6. Shiller, Robert J, 1979. "The Volatility of Long-Term Interest Rates and Expectations Models of the Term Structure," Journal of Political Economy, University of Chicago Press, vol. 87(6), pages 1190-1219, December.
    7. Ibbotson, Roger G & Sinquefield, Rex A, 1976. "Stocks, Bonds, Bills, and Inflation: Year-by-Year Historical Returns (1926-1974)," The Journal of Business, University of Chicago Press, vol. 49(1), pages 11-47, January.
    8. Richard Meese & Kenneth S. Rogoff, 1981. "Empirical exchange rate models of the seventies: are any fit to survive?," International Finance Discussion Papers 184, Board of Governors of the Federal Reserve System (U.S.).
    Full references (including those not matched with items on IDEAS)

    Citations

    Citations are extracted by the CitEc Project, subscribe to its RSS feed for this item.
    as


    Cited by:

    1. Jeffrey A. Frankel & James H. Stock, 1983. "A Relationship Between Regression Tests and Volatility Tests of Market ncy," NBER Working Papers 1105, National Bureau of Economic Research, Inc.
    2. Mankiw, N Gregory & Romer, David & Shapiro, Matthew D, 1985. "An Unbiased Reexamination of Stock Market Volatility," Journal of Finance, American Finance Association, vol. 40(3), pages 677-687, July.
    3. Robert J. Shiller, 1985. "Conventional Valuation and the Term Structure of Interest Rates," NBER Working Papers 1610, National Bureau of Economic Research, Inc.
    4. Ercan Balaban & Kursat Kunter, 1996. "Financial Market Efficiency in a Developing Economy : The Turkish Case," Discussion Papers 9611, Research and Monetary Policy Department, Central Bank of the Republic of Turkey.
    5. Zapart, Christopher A., 2015. "Econophysics: A challenge to econometricians," Physica A: Statistical Mechanics and its Applications, Elsevier, vol. 419(C), pages 318-327.
    6. Shiller, Robert J. & Huston McCulloch, J., 1990. "The term structure of interest rates," Handbook of Monetary Economics, in: B. M. Friedman & F. H. Hahn (ed.), Handbook of Monetary Economics, edition 1, volume 1, chapter 13, pages 627-722, Elsevier.
    7. Aboudou Ouattara, 2019. "Moderating Effects of Financial Transparency on Accounting Information¡¯s Transmission to Share Prices: The Case Study of Non-Financial Companies Listed at BRVM," Applied Economics and Finance, Redfame publishing, vol. 6(5), pages 35-52, September.
    8. Ercan Balaban & Kursat Kunter, 1996. "Stock Market Efficiency in a Developing Economy : Evidence from Turkey," Discussion Papers 9612, Research and Monetary Policy Department, Central Bank of the Republic of Turkey.

    Most related items

    These are the items that most often cite the same works as this one and are cited by the same works as this one.
    1. John Fender, 2020. "Beyond the efficient markets hypothesis: Towards a new paradigm," Bulletin of Economic Research, Wiley Blackwell, vol. 72(3), pages 333-351, July.
    2. Bradley Jones, 2015. "Asset Bubbles: Re-thinking Policy for the Age of Asset Management," IMF Working Papers 2015/027, International Monetary Fund.
    3. Blau, Benjamin M. & Whitby, Ryan J., 2020. "Gambling activity and stock price volatility: A cross-country analysis," Journal of Behavioral and Experimental Finance, Elsevier, vol. 27(C).
    4. Ariane Szafarz, 2009. "How Did Financial-Crisis-Based Criticisms of Market Efficiency Get It So Wrong?," Working Papers CEB 09-048.RS, ULB -- Universite Libre de Bruxelles.
    5. Stijn Claessens & M Ayhan Kose, 2018. "Frontiers of macrofinancial linkages," BIS Papers, Bank for International Settlements, number 95.
    6. Berneburg, Marian, 2006. "Excess Volatility in European Equity Style Indices - New Evidence," IWH Discussion Papers 16/2006, Halle Institute for Economic Research (IWH).
    7. Bachar Fakhry & Christian Richter, 2015. "Is the sovereign debt market efficient? Evidence from the US and German sovereign debt markets," International Economics and Economic Policy, Springer, vol. 12(3), pages 339-357, September.
    8. Christiane Goodfellow & Dirk Schiereck & Steffen Wippler, 2013. "Are behavioural finance equity funds a superior investment? A note on fund performance and market efficiency," Journal of Asset Management, Palgrave Macmillan, vol. 14(2), pages 111-119, April.
    9. Thomas Delcey, 2019. "Samuelson vs Fama on the Efficient Market Hypothesis: The Point of View of Expertise [Samuelson vs Fama sur l’efficience informationnelle des marchés financiers : le point de vue de l’expertise]," Post-Print hal-01618347, HAL.
    10. Paulo M.M. Rodrigues & Rita Fradique Lourenço, 2015. "House prices: bubbles, exuberance or something else? Evidence from euro area countries," Working Papers w201517, Banco de Portugal, Economics and Research Department.
    11. Dmitry Kulikov, 2012. "Testing for Rational Speculative Bubbles on the Estonian Stock Market," Research in Economics and Business: Central and Eastern Europe, Tallinn School of Economics and Business Administration, Tallinn University of Technology, vol. 4(1).
    12. Pavlidis, Efthymios & Martínez-García, Enrique & Grossman, Valerie, 2019. "Detecting periods of exuberance: A look at the role of aggregation with an application to house prices," Economic Modelling, Elsevier, vol. 80(C), pages 87-102.
    13. Flood, Robert P & Hodrick, Robert J, 1986. "Asset Price Volatility, Bubbles, and Process Switching," Journal of Finance, American Finance Association, vol. 41(4), pages 831-842, September.
    14. Eugene N. White, 2004. "Bubbles and Busts: The 1990s in the Mirror of the 1920s," FRU Working Papers 2004/09, University of Copenhagen. Department of Economics. Finance Research Unit.
    15. Barberis, Nicholas & Greenwood, Robin & Jin, Lawrence & Shleifer, Andrei, 2015. "X-CAPM: An extrapolative capital asset pricing model," Journal of Financial Economics, Elsevier, vol. 115(1), pages 1-24.
    16. Michael Demmler & Amilcar Orlian Fernández Domínguez, 2021. "Bitcoin and the South Sea Company: A comparative analysis," Revista Finanzas y Politica Economica, Universidad Católica de Colombia, vol. 13(1), pages 197-224, March.
    17. Wang, Yuming & Ma, Jinpeng, 2014. "Excess volatility and the cross-section of stock returns," The North American Journal of Economics and Finance, Elsevier, vol. 27(C), pages 1-16.
    18. Lim, Kian-Ping & Kim, Jae H., 2011. "Trade openness and the informational efficiency of emerging stock markets," Economic Modelling, Elsevier, vol. 28(5), pages 2228-2238, September.
    19. Kaliva, Kasimir & Koskinen, Lasse, 2008. "Stock market bubbles, inflation and investment risk," International Review of Financial Analysis, Elsevier, vol. 17(3), pages 592-603, June.
    20. Froot, Kenneth A & Obstfeld, Maurice, 1991. "Intrinsic Bubbles: The Case of Stock Prices," American Economic Review, American Economic Association, vol. 81(5), pages 1189-1214, December.

    More about this item

    Statistics

    Access and download statistics

    Corrections

    All material on this site has been provided by the respective publishers and authors. You can help correct errors and omissions. When requesting a correction, please mention this item's handle: RePEc:nbr:nberwo:0994. See general information about how to correct material in RePEc.

    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 CitEc recognized a bibliographic reference but did not link an item in RePEc 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 RePEc Author Service profile, as there may be some citations waiting for confirmation.

    For technical questions regarding this item, or to correct its authors, title, abstract, bibliographic or download information, contact: the person in charge (email available below). General contact details of provider: https://edirc.repec.org/data/nberrus.html .

    Please note that corrections may take a couple of weeks to filter through the various RePEc services.

    IDEAS is a RePEc service. RePEc uses bibliographic data supplied by the respective publishers.