Posts Tagged ‘Richard Thaler’

Richard H. Thaler, Chicago School economist and co-author (along with Werner F.M. DeBondt) of Further Evidence on Investor Overreaction and Stock Market Seasonality, and the “Thaler” in Fuller & Thaler Asset Management, has written an opinion piece for the NYTimes.com “The Overconfidence Problem in Forecasting.”

Thaler says:

BUSINESSES in nearly every industry were caught off guard by the Great Recession. Few leaders in business — or government, for that matter — seem to have even considered the possibility that an economic downturn of this magnitude could happen.

What was wrong with their thinking? These decision-makers may have been betrayed by a flaw that has been documented in hundreds of studies: overconfidence.

Most of us think that we are “better than average” in most things. We are also “miscalibrated,” meaning that our sense of the probability of events doesn’t line up with reality. When we say we are sure about a certain fact, for example, we may well be right only half the time.

He then discusses a recent paper that shows that overconfidence permeates the top reaches of large companies:

In that paper, three financial economists — Itzhak Ben-David of Ohio State University and John R. Graham and Campbell R. Harvey of Duke — found that chief financial officers of major American corporations are not very good at forecasting the future. The authors’ investigation used a quarterly survey of C.F.O.’s that Duke has been running since 2001. Among other things, the C.F.O.’s were asked about their expectations for the return of the Standard & Poor’s 500-stock index for the next year — both their best guess and their 80 percent confidence limit. This means that in the example above, there would be a 10 percent chance that the return would be higher than the upper bound, and a 10 percent chance that it would be less than the lower one.

It turns out that C.F.O.’s, as a group, display terrible calibration. The actual market return over the next year fell between their 80 percent confidence limits only a third of the time, so these executives weren’t particularly good at forecasting the stock market. In fact, their predictions were negatively correlated with actual returns. For example, in the survey conducted on Feb. 26, 2009, the C.F.O.’s made their most pessimistic predictions, expecting a market return of just 2.0 percent, with a lower bound of minus 10.2 percent. In fact, the market soared 42.6 percent over the next year.

Thaler concludes:

Two lessons emerge from these papers. First, we shouldn’t expect that the competition to become a top manager will weed out overconfidence. In fact, the competition may tend to select overconfident people. One route to the corner office is to combine overconfidence with luck, which can be hard to distinguish from skill. C.E.O.’s who make it to the top this way will often stumble when their luck runs out.

The second lesson comes from Mark Twain: “It ain’t what you don’t know that gets you into trouble. It’s what you know for sure that just ain’t so.”

Read the article.

For more on Richard H. Thaler, see the post archive.


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The New Yorker has John Cassidy’s interview with Richard Thaler, Chicago School economist and co-author (along with Werner F.M. DeBondt) of Further Evidence on Investor Overreaction and Stock Market Seasonality, a paper I like to cite in relation to low P/B quintiles and earnings mean reversion. Thaler is also the “Thaler” in Fuller & Thaler Asset Management, which James Montier identifies in his 2006 research report Painting By Numbers: An Ode To Quant as being a “fairly normal” quantitative fund (as opposed to being “rocket scientist uber-geeks”) with an “admirable track [record] in terms of outperformance.” I diverge from Thaler on a number of issues, but on these two I think he’s right:

On the remnants of efficient markets hypothesis:

Well, I always stress that there are two components to the theory. One, the market price is always right. Two, there is no free lunch: you can’t beat the market without taking on more risk. The no-free-lunch component is still sturdy, and it was in no way shaken by recent events: in fact, it may have been strengthened. Some people thought that they could make a lot of money without taking more risk, and actually they couldn’t. So either you can’t beat the market, or beating the market is very difficult—everybody agrees with that. My own view is that you can [beat the market] but it is difficult.

The question of whether asset prices get things right is where there is a lot of dispute. Gene [Fama] doesn’t like to talk about that much, but it’s crucial from a policy point of view. We had two enormous bubbles in the last decade, with massive consequences for the allocation of resources.

On stock market bubbles:

[Cassidy] When I spoke to Fama, he said he didn’t know what a bubble is—he doesn’t even like the term.

[Thaler] I think we know what a bubble is. It’s not that we can predict bubbles—if we could we would be rich. But we can certainly have a bubble warning system. You can look at things like price-to-earnings ratios, and price-to-rent ratios. These were telling stories, and the story they seemed to be telling was true.

And I love this line in relation to the impact of the recent crisis on behavioral economics:

I think it is seen as a watershed, but we have had a lot of watersheds. October 1987 was a watershed. The Internet stock bubble was a watershed. Now we have had another one. What is the old line—that science progresses funeral by funeral? Nobody changes their mind.

Science progresses funeral by funeral. Nobody changes their mind. It seems to me it’s not the only discipline that proceeds by funeral.

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