Wednesday, October 10, 2007

Prediction Markets and The Nobel Prize in Economics

The lists of likely Nobel Economics Prize winners have started. I chose Eugene Fama for last year's prize based on his early work supporting market efficiency and his more recent work examining weaknesses in the tradional Capital Asset Pricing Model (CAPM). You've just gotta love an academic with the stones to turn his back on his career-making earlier work when he finds new evidence that contradicts it.

But last year, I came up with bupkes/nada/diddly. So this time I'll stick with the same hand.

In case you're interested, InTrade has opened trading in the Nobel Prize contracts. Fama's currently leading the pack in the econ trading, but it's still early.

HT: Greg Mankiw

Update: When I wrote the original post, I probably should have chosen my a better phrase than "debunking" when referring to Fama's recent work . I was referring to his work with Kenneth French on Size and Book-to-Market as proxies for factors with more explanatory power than the traditional CAPM "beta" in explaining returns. So a more correct way of describing Fama's later work would be "debunking the traditional CAPM model".

One way to interpret his work with French is that there are risk factors (size, book to market) other than the CAPM systematic risk beta that are priced in the market. So he's not exactly taking shots at the efficient markets hy[pothesis rather than at the risk-return model that was most often used to test it.

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