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Behavioral Finance. Economics 437. General Theme: Predictability. Fama French: “Cross Section” Article Book/Market and Size => Stock Returns “Value Investing” or “Contrarian Investing” DeBondt Thaler: “Over Reaction” Buy past losers; Sell past winners Value? Investing; Contrarian Investing
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Behavioral Finance Economics 437
General Theme: Predictability • Fama French: “Cross Section” Article • Book/Market and Size => Stock Returns • “Value Investing” or “Contrarian Investing” • DeBondt Thaler: “Over Reaction” • Buy past losers; Sell past winners • Value? Investing; Contrarian Investing • Jegadeesh Titman: “Price Momentum” • Possibly “Earnings Momentum”
DeBondt-Thaler 1984 • “Over-Reaction” Hypothesis • Suggests that: • After a period of “over-reaction,” markets “revert” back and go the other way. • Stocks that have done well in the past, do poorly in the future • Stocks that done poorly in the past, do well in the future • Their article is designed to test whether or not “mean reversion” is true.
Data • NYSE data • Jan 1926 through December 1982 • Monthly return data • Begin with three year lookback in Dec 1932 • Monthly data from Jan 1930 through Dec 1932 • 36 months or three years data • Form portfolios of L(osers) and W(inners) • Then see how they do for the next three years
DeBondt and Thaler: “Does the Stock Market Overreact” (1985) • L – three year loses • W – three year winners • Question: How do the W’s do in the next three years? How do the L’s do in the next three years? • Other things worth noting • Almost all of the impact is in January • When the W portfolios are formed, they have very high P/E ratios, the L portfolios have low P/E ratios at the time of formation
DeBondt-Thaler conclusions • Definite evidence of mean reversion (a form of serial correlation): • L portfolios consistently outperform W portfolios • 19.6 % better than the market after end of 3 years • W portfolios consistently underperform the market • 5 % less than the market after end of 3 years
Interesting facts • Most of the excess returns are in January • Loser effect more pronounced: • Losers earned 19.6 % more than the market • Winners earn 5.0 % less than the market • Loser portfolio minus Winner portfolio return = 24.6 %!!!!! • Most of the return difference is during 2nd and 3rd year • Larger loses become larger winners; larger winners become larger losers
Data in Fama and French • 1962 -1989 data • Book Value (leverage and price/earnings) at previous year end • Returns starting on July 1 of the following year (also use the market equity as of July 1 for size, but use market equity at previous year end for B/M calculation) • Calculate monthly returns • Each month the cross-section of returns is regressed on explanatory variables. • Prior • research used “portfolio betas”; F-F use individual stocks • Sort stocks into “size deciles” • Sort each size decile into 10 portfolios based on beta • Calculate equal weighted monthly returns on the portfolios for the next 12 months (from July to June).
Results on Beta • Portfolios in size deciles (without breaking them into 10 beta portfolios) show a relationship between beta and return • Large size means lower beta and lower returns • When size deciles are subdivided into beta ranked decile portfolios • Larger size firms have lower returns • “no relation between average return and beta”
Results on Book/Market • What is book to market • Book is firm net worth reported on 10-Ks • Market is: shares outstanding times price • Book/market is positively related to returns • Size still matters but B/M is much more important • B/M swamps leverage and E/P • Leverage: book or market leverage? • January “slopes” twice slopes of other months • Overall largest decile book to market beats smallest decile book to market by 1.53 % per month
Jegadeesh and Titman (1993) • Relative strength strategies, sometimes called “earnings momentum” strategies • Find past winners and and past losers (using 3 to 12 month holding periods) generate gains (winners gain; losers lose) • Construct W portfolio and L portfolio • W-L (using 6 month periods) earns more than12 % better than market portfolio • Longer term portfolios do best in next 12 months • Interpretation in “event time” • Doesn’t work in January
Ball & Brown 1986 • Market “underreacts” to earnings surprises • Article generally ignored until Jagdeesh-Titman • Time span suggests that Ball-Brown effect may be the same thing as Jagdeesh-Titman