Benoit Mandelbrot on the Efficient Market Hypothesis

Below, Jonathan Authers of the Financial Times interviews the eminent mathematician Benoit Mandelbrot¹. Sorry about this video automatically launching into play. I didn't see an embed feature so I cut and pasted the source code here. Update: Thanks to Alex Garcia, here's the embedded version, via YouTube:




¹I wonder if Dr. Mandelbrot knows that Jonathan Coulton made this song about him, Mandelbrot Set. Here are the lyrics to the chorus:

Take a point called Z in the complex plane
Let Z₁ be Z squared plus C
And Z₂ is Z₁ squared plus C
And Z₃ is Z₂ squared plus C and so on
If the series of Z’s should always stay
Close to Z and never trend away
That point is in the Mandelbrot Set

John Hussman's Latest Weekly Market Commentary

In his current market commentary, "Ambiguous Conditions Warrant Moderation", Dr. Hussman gives his opinion on the comparisons of today's economic environment to the Great Depression, finishing with a clever simile:

We continue to hear remarks that the current economic downturn is the worst since the Great Depression. While the prices of stocks and other financial assets have certainly suffered a great deal, by any reasonable measure of output and employment, this isn't even close to being the worst economic downturn since the Depression. Even after November's awful job report, and including all of the downward revisions, the U.S. economy would have to lose twice as many jobs as it has already lost even to be on par with the 1981-82 recession (measuring job losses as a percentage of the labor force).

While we do expect fourth-quarter GDP to come in at a loss of -4% to -6%, it is important to recognize that this is a quarterly change at an annual rate. The overall contraction in U.S. output will be somewhere about 1-1.5% in the fourth quarter. In the Great Depression, actual GDP dropped by 30%. Ben Bernanke was correct in remarks he made last week that there is “an order of magnitude” (10 fold) difference between the current downturn and the Great Depression. For the record, the worst overall drawdowns in GDP since the Depression – not just bad quarterly growth rates – were in 1954 (-2.65%), 1958 (-3.75%), 1975 (-3.10%), and 1982 (-2.87%).

This is not to minimize the prospects for a further economic downturn, but to say that this is “the worst economy since the Great Depression” is like blowing up a crate of dynamite on the Nevada Proving Grounds and saying it is the worst explosion since the detonation of the atomic bomb there. Even if the statement is accurate, the comparison is absurd.

Unlike Bill Gross and John Authers (see "Bill Gross on Stock Valuations"), Hussman does not believe corporate bonds are more attractive than equities at this point:

Corporate yields have increased significantly, but default rates tend to pick up in the later stages of recessions, and there isn't much historical evidence to suggest that corporate bonds reach their lows any earlier than stocks do. For that reason, corporate bonds are essentially equity-equivalents here, and the same considerations about quality apply as well here as they do for stocks. Generally speaking, corporate bonds are currently priced to deliver both lower long-term returns than stocks, but as a group, will probably have lower volatility than stocks as well. Our inclination to invest in corporates for the Total Return Fund will likely increase at about the same time as our willingness to hold stocks on an unhedged basis for Strategic Growth (which is not yet).