Monday, October 24, 2011

Luck running out?

There's an article by behavioral economist Daniel Kahneman, excerpt from a new book, in the Times Magazine this week that should upset Wall Street even more than the Occupiers. Kahneman describes research which finds that the stock market cannot be played. Two thirds of mutual funds underperform in any given year, and no fund outperforms the rest of the mutual funds over time. When the performances of various stock advisers in an investment firm was compared with each other and their own performance in other years, the correlation between yearly rankings and overall performance was... zero! In highly efficient markets ... educated guesses are not more accurate than blind guesses. ... the firm was rewarding luck as if it were skill. (33, 62) Our whole society has been rewarding luck as if it were skill, and bet our futures on the sort of "illusion of validity" Kahneman has exposed.

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