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Are Markets Rational? Part 1 Adapted from Haugen, Ch. 15: “The Wrong 20-Yard Line”. References. Reilly & Brown, Ch. 7 – “Efficient Capital Markets” Haugen, Ch. 15 – “The Wrong 20-Yard Line” Mauboussin ( www.capatcolumbia.com ) – “Shift Happens”
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Are Markets Rational?Part 1Adapted from Haugen, Ch. 15: “The Wrong 20-Yard Line”
References • Reilly & Brown, Ch. 7 – “Efficient Capital Markets” • Haugen, Ch. 15 – “The Wrong 20-Yard Line” • Mauboussin (www.capatcolumbia.com) – “Shift Happens” • Hagstrom, Ch. 8 – “The Market as a Complex Adaptive System” • Rubinstein (Financial Analysts Journal, 2001) – “Rational Markets: Yes or No? The Affirmative Case” • Fortune (3 Dec. 2002) – “Is the Market Rational?”
Forms Of EMT • Weak Form • Prices reflect all historical information • Price changes follow a random walk • “Tests of Return Predictability” • Technical Analysis • Semi-Strong Form • Prices reflect all public information • “Event Studies” • Fundamental Analysis • Strong Form • Prices reflect all public and private information • “Tests for Private Information” • Insider Trading
Weak Form EMH • Supported by: • Studies on Autocorrelation • Tests of Filter Rules • Contradicted by: • Seasonality • January Effect • Day-of-the-Week Effect • Long-term overreaction/reversal patterns
Semi-Strong Form EMH • Supported by: • Most Event Studies • Contradicted by: • Various Accounting Anomalies • Size Effect • M/B Effect • Neglected Firm Effect
Summary on Semi-Strong Form EMH • Market seems to do a relatively good job at adjusting a stock’s valuation for certain types of new information • Determining how much the new info. will change the stock’s value and then adjusting the price by an equivalent amount • This is what event studies examine • But it seems to have problems developing an overall valuation for a stock in the first place • E.g., What is the correct value for IBM as a whole is a very difficult question to answer, but how much IBM’s value should change if it is awarded a specific new contract is much easier to determine
Strong Form EMH • Supported by: • Under-performance of most fund managers • Most are beaten by the market averages • Contradicted by: • Returns following insider purchases • Value Line effect • Consistent outperformance of some fund managers • Notably, Warren Buffett and the “Superinvestors of Graham-and-Doddsville”
Fund Managers • Trained professionals, working full time at investment management • If any investor can achieve above-average returns, it should be this group • If any non-insider can obtain inside information, it would be this group, due to the extensive management interviews that they conduct • But, Peter Lynch criticism: • “have blinders on” • Also …
Fund Managers • Quote from “Wall Street:” • “Do you want to know why fund managers can’t beat the S&P 500? Because fund managers are sheep … and sheep get slaughtered.” • Problems Fund Managers Face: • Administrative expenses and trading costs • Agency problems that contribute to poor performance • Compensation structure that encourages “sheep-like” behavior
Tests and Results of EMH • Many results tend to support EMH • Event studies • Performance of most fund managers • But many other results tend to contradict EMH • Performance of Buffett • Numerous anomalies & long-run overreaction/reversals • So, are markets efficient (or rational) or not? • Need to examine whether markets can be beaten, after adjusting for risk • But, how should you model and measure risk? CAPM? APT?
Tests and Results of EMH • Tests face a joint hypothesis problem • Results are dependent on both of two factors: • Market efficiency • Is the stock’s price equal to its true value? • Asset pricing model used (CAPM, APT, etc.) • What is the stock’s true value? • So, are the markets efficient or rational? • Ultimately, can never answer definitively • Mauboussin’s view (“Shift Happens”): stock market as a chaotic or complex adaptive system • Haugen’s view follows …
Haugen’s Trilogy • “The New Finance” • “Beast on Wall Street” • “The Inefficient Stock Market”
“The New Finance” • Focuses on the market’s major systematic error: • Fails to appreciate the strength of competitive forces in a market economy • Over-estimates the length of the “short run” • Over-reacts to records of success and failure for individual companies • Drives the prices of successful companies too high • Drives the prices of unsuccessful companies too low • So: • Successful firms tend to experience negative earnings surprises down the road • Unsuccessful firms tend to benefit from positive earnings surprises
Changing Investor Opinion as to the Length of the Short Run • Prior to 1924 • Stock valuation based on current normalized earnings. • 1925 • E. L. Smith advises stock valuation based on future growth - New Era Theory. • Growth stocks start to take off, followed by Crash of ’29 • Leads to development of Graham & Dodd approach • 1934 • Graham and Dodd dispute New Era Theory’s views on growth and valuation. • Lessons learned until Go-go years of ’60’s • 1960’s • Growth stock investing makes comeback.
But … • Successful growth stock investing requires some degree of persistence in earnings growth, • while the speed of mean-reversion in earnings growth appears to be quite fast. • If, in general, it is faster than the market expects, cheap (expensive) stocks should tend to grow faster (slower) than expected. • If this happens, cheap stocks should tend to out-perform expensive stocks.
The Relative Performance of Portfolios Equally-weighted in the Cheap and Expensive Quartiles • The difference in cumulative return of value stocks relative to growth stocks is measured over rolling 5-year periods. • The relative performance appears to cycle over time. • Cheap (value) stocks out-perform more often than not.
Rolling Annualized Average 5-year Difference Between the Returns to Value and Growth Composites 50% 40% 30% 20% Relative Difference 10% 0% 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1997 1993 1994 1996 1992 1995 -10% -20% Year
14% 12% January Prior Losers 10% Feb. - Dec. Average Monthly 8% Return 6% 4% 2% 0% 1 Prior Winners 2 3 4 5 6 7 8 9 10 11 12 13 Rank based on Previous 5-year Return 14 15 16 17 18 19 20 Seasonal Returns to Value and Growth Portfolios
What has Over-estimation of the Length of the Short Run Done to Risk and Return? • Cheap (expensive) stocks tend to have surprisingly high (low) realized returns • Cheap (expensive) stocks tend to have low (high) volatility, because little (much) is expected of them • Investors may expect higher returns from expensive stocks but they may be repeatedly surprised by disappointing earnings reports • Thus, the relationship between risk and return appears to be upside-down
How Long Have Risk and Return Been Up-side Down? • If it’s caused by an over-estimation of the short run, it should begin with the renaissance of growth stock investing at the end of the 1950’s. • What has been the relative performance between the low-volatility stock portfolio and the market index over time?
Cumulative Difference 25% 15% 5% -5% -15% -25% -35% 1928 1938 1948 1958 1968 1978 1988 Cumulative Difference in Return Between Low Volatility Portfolio and S&P 500
The Relationship Between the Perceived and True Growth Horizon and Average Growth Rates • Define the growth horizon (or growth duration, see Ch. 20) as the length of time a typical stock takes to mean-revert to the average rate of earnings growth. • The evidence indicates that the perceived horizon is longer than the true horizon.
The Relationship Between the Perceived and True Growth Horizon and Average Growth Rates • The true horizon tends to be relatively constant, but investor perceptions may change. • If investors perceive that relative differences in growth will persist for longer periods, growth stocks may out-perform. • Changes in the perceived horizon may create a cycle in growth/value performance.
Rolling Annualized Average 5-year Difference Between the Returns to Value and Growth Composites 50% 40% 30% 20% Relative Difference 10% 0% 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1997 1993 1994 1996 1992 1995 -10% -20% Year
“Beast on Wall Street” • 2nd book in trilogy • Focuses on stock volatility • Three components of volatility
Three Components of Stock Volatility • Event-driven volatility • Error-driven volatility • Price-driven volatility
High-wire Act at the Financial Circus The wireThe economy The aerialists Different stocks Movements in Movements in balance bars stock prices
Components of the Movements in the Balance Bars • Event-driven The best moves in the bars humanly possible • Error-driven Over- and under-reactions to shocks in the wire • Price-driven Aerialists interacting with each other
The Types of Volatility Contrasted • Event-driven and error-driven volatility are caused by investors [over]reacting to specific information that could be expected to affect stock values • Price-driven volatility, on the other hand, works in the opposite direction – it is caused by investors reacting to what is happening in the stock market itself • i.e., there is a reassessment of stock valuations solely as a consequence of changes in stock prices … • rather than stock prices changing as a consequence of changes in stock valuations that are being driven by outside information • This is similar to Keynes’ and Graham’s views
“We have reached the third degree where we devote our intelligence to anticipating what average opinion expects the average opinion to be.” • Keynes • “For stock speculation is largely a matter of A trying to decide what B, C, and D are likely to think – with B, C, and D trying to do the same.” • Graham and Dodd
Synthesis The results of many old studies, when considered together, point to startling new conclusions.
Contentions • Price-driven volatility is the largest of the three components. • Price-driven volatility is explosive. • Price-driven volatility is an important drag on long-run economic growth. • Explosions in Price-driven volatility create disruptions in economic activity. • For example. the Great Crash of 1929 helped cause the Great Depression.
Mysteries of the Stock Market • Too much stock volatility (Shiller, American Economic Review, 1981)
34 30 26 22 30 P/E 18 14 10 6 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 Year Market Price and Perfect Forecast Price: Constant Discount Rates Pt / Et30 PFt / Et30
Mysteries of the Stock Market • Too much stock volatility • Volatility too unstable (Haugen, Talmor, and Torous, Journal of Finance, 1991)
Volatility Shifts Over 8-week Trading Periods • HTT find (with 99% confidence) 402 cases where volatility becomes significantly larger or smaller between the first and second 4-week blocks.
Realization of Risk Premiums Following the Price-level Adjustments • Following the price-adjustments to volatility changes, subsequent stock returns are, on average, 460 basis points higher following volatility increases. (The higher required returns are apparently realized.) • Interestingly, only 10% of the shifts have an associated cause traceable in the media.
Mysteries of the Stock Market • Too much stock volatility • Volatility too unstable • Unconnected market (Cutler, Poterba, and Summers, Journal of Portfolio Management, 1989)
Percentage Changes in Stock Prices on 49 Historic Days Examples: Pearl Harbor Attacked -4.37% Roosevelt Dies 1.07% Bay of Pigs .47% John Kennedy Assassinated -2.81% Robert Kennedy Assassinated -.49% Chernobyl -1.06%
Percentage Changes in Stock Prices on Historic Days • Average absolute return over 49 historic days 1.46% • Average absolute return over all other days .56%(standard deviation: .82%)
“Events” Associated with the Five Largest One-day Percentage Changes in Stock Prices Worry over dollar (10/19/87) -20.47% Deficit talks in Wash. (10/21/87)9.10% Fear of deficit (10/26/87)-8.28% No reason for decline (09/03/46)-6.73% Roll-back of steel prices (05/28/62)-6.68%
Haugen vs. Mauboussin • Note that the previous observation is consistent with Mauboussin’s hypothesis of the financial markets as a complex adaptive system • Nonlinearity causes stock price movements to bear little relation to specific definable causes
“The Inefficient Stock Market” • 3rd book in Haugen’s trilogy • Focuses on expected return factor models • Attempt, in part, to exploit error-driven volatility • Positive payoff to cheapness results from market’s overreaction to success and failure • Positive payoff to intermediate term momentum results from the market’s underreaction to positive and negative earnings surprises in individual earnings reports • Also exploit the distortions in the structure of stock prices brought about by price-driven volatility
It’s Tough to Beat the Market • It the market is so inefficient, why isn’t beating it “like taking candy from a baby?” • Two reasons: • Many professional investors are victims of their own agency problems • More importantly, a gale of unpredictable price-driven volatility stands between investors and the “candy”
It’s Tough to Beat the Market • Professional investors are victims of agency problems • Easier to make a “story” for growth stocks than for value stocks • Worry about “benchmark risk” rather than total risk • Portfolio managers need to keep up with market on a fairly steady basis or risk losing their jobs • Gale of unpredictable price-driven volatility stands between investors and consistent profits • Price-driven volatility is unpredictable, increasing the element of chance in stock returns • Even after maximizing predictability of stock returns, only 10% of differences in monthly stock returns can be explained by model • Overvalued growth stocks can always go up even more before finally “coming down to earth”
The Wrong 20-Yard Line • Spectrum of market efficiency equivalent to positions on a football field • At one end zone, perfectly efficient markets • At other end, completely inefficient markets
The Wrong 20-Yard Line Near efficient markets end zone (the left end zone): • All volatility is event-driven • Models based on rational economic behavior do a good job of explaining and predicting market pricing • No under- or over-valued stocks, so no role for active investment • No inefficiencies for active managers to exploit • Fact that fund managers tend to underperform the market taken as evidence that markets are efficient
The Wrong 20-Yard Line Near the other endzone (the right end zone): • All volatility is price-driven • Market pays no attention whatsoever to fundamentals • Market, in the short-term, is in a state of complete and unpredictable chaos
The Wrong 20-Yard Line As we move from the left to the right end zone: • Models based on rational economic behavior begin to lose power • As you cross midfield, behavioral models begin to dominate • Note: under these models, markets have biased reactions to real economic events, but they do still react to real economic events • As you move to the extreme right, even behavioral models lose power, and the market reacts only to its own events (at least in the short run) • Aerialists pay no attention to the wire whatsoever
The Wrong 20-Yard Line Active managers would perform best when the market is near the 60-yard line: • Too close to the efficient markets end zone, and there are no inefficiencies for the active managers to exploit • Too close to the inefficient markets end zone, and unpredictable, price-driven volatility begins to dominate, making it nearly as impossible for active managers to beat the market as at the right end zone • Best way to do well in this case would be by buying future dividend streams at relatively cheap prices, cf., Warren Buffett • Lack of clear success by active managers indicates only that we are near one of the end zones, not which one we are near