Behavioral Finance Mean Reversion March 22 Behavioral Finance Economics 437

Behavioral Finance Mean Reversion March 22 A Few More Anomalies

Behavioral Finance Mean Reversion March 22 Mathematical Illusions Adam switches from a gas-guzzler of 12 mpg to a slightly less voracious guzzler that runs at 14 mpg The environmentally virtuous Beth switches from a 30 mpg car to one that runs at 40 mpg Who saves more gas?

Behavioral Finance Mean Reversion March 22 The Story La Traviata Alfredo and Violetto Father Germont Ten minutes at the end What if she he didn’t make it in time Duration? The Mythical Jen Adding five “slightly happy” years lowered the perception of observers of her overall happiness

Behavioral Finance Mean Reversion March 22 The Story Again Pain experiments No pain for 2 minutes; pain for 30 seconds Pain for 1 minute; no pain for 1 ½ minutes After being administered both, patients preferred the first over the second

Behavioral Finance Mean Reversion March 22 How happy are you? Two groups enter two separate rooms Each member of one group finds a dollar bill on the ground just as they enter Which reports being happier?

Behavioral Finance Mean Reversion March 22 Thinking Fast and Slow Fast thinking is probably an evolutionary outcome Slow thinking is probably the way to go for important decisions (when you have the time) Some things (like risk aversion) might be bad for you, other things (overoptimisim) might be good for society.

Behavioral Finance Mean Reversion March 22 Naïve Diversification Four Choices: Three Bond Funds One Stock Fund Put ¼ in each Four Other Choices Three Stock Funds One Bond Fund Put ¼ in each

Behavioral Finance Mean Reversion March marbles, randomly divided among five children I II Alan 4 4 Ben 4 4 Carl 5 4 Dan 4 4 Ed 3 4 In many rounds of random assignment, which of these results is more likely?

Behavioral Finance Mean Reversion March 22 [ Mr. Crane and Mr. Tees arrive ½ hour late for a flight. Mr Crane is told that his flight left on time. Mr. Tees is told that his flight was delayed 25 minutes and left five minutes ago. Who was more upset?] A. [Mr. Crane] B. [Mr. Tees] C. [No Difference]

Behavioral Finance Mean Reversion March 22 Here’s an easy one Two hospitals, large one, small one 45 babies born each day in large hospital 15 babies born each day in small hospital On average, 50 % of babies are male Over the course of a year, which has hospital has more days when 60% or more babies born are male? The large one or the small one?

Behavioral Finance Mean Reversion March 22 If you draw a red marble, you get $ 1,000 Urn 1 has 10 marbles, only one is red Urn 2 has 100 marbles, eight are red

Behavioral Finance Mean Reversion March 22 Predictions Paul Meehl High school grades; one aptitude test Outperformed complex batteries of test “Clinical vs Statistical” Prediction Dr. Apgar Five variables: (heart rate, respiration, reflex, muscle tone, color)…give it a 0,1,2 Score of 8 or above – great! Score of 4 or less – trouble!

Behavioral Finance Mean Reversion March 22 Analyzing Past Success Books about great business leaders Ignore “right place, right time” phenomenon Chance may be more important “Outliers” by Malcolm Gladwell “I was smart” versus “I was lucky”

Behavioral Finance Mean Reversion March 22 Optimism and Overconfidence Business start ups Four in five fail But, no one ever assumes they are in the “four”

Behavioral Finance Mean Reversion March 22 Regret Mr. Brown almost never picks up hitchhikers. Yesterday he gave a man a ride and was robbed Mr. Smith frequently picks up hitchhikers. Yesterday, he gave a man a ride and was robbed Which of the two will experience greater regret? Who will be criticized most severely by others?

Behavioral Finance Mean Reversion March 22 Another Framing Example The one-month survival rate is 90 % There is a 10 % mortality rate in the first month Do these sound different to you?

Behavioral Finance Mean Reversion March 22 Trader Folk Lore Stock Price Momentum Charting stocks by tracking stock prices Trend following Mean Reversion Returns will revert to a mean return Stocks with very high returns will, in the future, underperform stocks with very low returns Other Buy in December, Sell on Friday night, buy on Monday night

Behavioral Finance Mean Reversion March 22 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.

Behavioral Finance Mean Reversion March 22 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

Behavioral Finance Mean Reversion March 22 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 2 nd and 3 rd year Larger loses become larger winners; larger winners become larger losers

Behavioral Finance Mean Reversion March 22 What was the reaction to D-T Largely ignored by the academic literature Then, in 1992, along came Fama-French on “Cross-Section” returns

Behavioral Finance Mean Reversion March 22 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

Behavioral Finance Mean Reversion March 22 The End