Are Stocks Really Less Volatile in the Long Run?
University of Chicago - Booth School of Business; Centre for Economic Policy Research (CEPR); National Bureau of Economic Research (NBER)
Robert F. Stambaugh
University of Pennsylvania - The Wharton School; National Bureau of Economic Research (NBER)
NBER Working Paper No. w14757
According to conventional wisdom, annualized volatility of stock returns is lower when computed over long horizons than over short horizons, due to mean reversion induced by return predictability. In contrast, we find that stocks are substantially more volatile over long horizons from an investor’s perspective. This perspective recognizes that parameters are uncertain, even with two centuries of data, and that observable predictors imperfectly deliver the conditional expected return. Mean reversion contributes strongly to reducing long-horizon variance, but it is more than offset by various uncertainties faced by the investor, especially uncertainty about the expected return. The same uncertainties also make target-date funds undesirable to a class of investors who would otherwise find them appealing.
Number of Pages in PDF File: 54working papers series
Date posted: February 26, 2009
© 2013 Social Science Electronic Publishing, Inc. All Rights Reserved.
This page was processed by apollo1 in 0.531 seconds