Edit: Apparently they've just recently started using real money at some prediction markets: http://en.wikipedia.org/wiki/Prediction_market#Legality
Edit: Apparently they've just recently started using real money at some prediction markets: http://en.wikipedia.org/wiki/Prediction_market#Legality
[1] http://www.overcomingbias.com/tag/prediction-markets (easily one of top 5 blogs on the Internet)
http://unqualified-reservations.blogspot.com/2010/02/pipe-sh...
I won't go into much detail (the post is worth reading), but his basic point (which I agree with) is that the reason a prediction market works (when it works) is that the only incentive governing people's bets is their beliefs about the expected probabilities of outcomes. But this can only work if the bets people make are themselves statistically independent of the outcomes, and in a decision market they obviously can't be, since people's bets determine the outcome. (In the post Moldbug gives an actual real-world example of a market which gets manipulated in exactly this way.)
It was pretty easy to sell the idea, but invariably once the contract landed in the legal department they'd put the brakes on, and we'd have to do some contortions involving play money that gets converted to real money and so forth. Once you start taking the real money out of the equation the results are a bit more suspect.
Nevertheless we did manage to convince a major media company, a couple large pharma companies, and an advertising company to set up some small scale prediction markets.
That, of course, depends where you are - in some countries online gambling is completely legal.
I believe the Fed's recent interest in them had something to do with Intrade closing down.
Here's a snippet from a forum thread that's relevant:
http://forums.randi.org/showthread.php?t=125104
From Wikipedia: Because online gambling is outlawed in the United States through federal laws and many state laws as well, most prediction markets that target U.S. users operate with "play money" rather than "real money": they are free to play (no purchase necessary) and usually offer prizes to the best traders as incentives to participate. Notable exceptions are Intrade/TradeSports, which escapes U.S. legal restrictions by operating from Dublin, Ireland, where gambling is legal and regulated, and the Iowa Electronic Markets, which operates from the University of Iowa under the cover of a no-action letter from the Commodity Futures Trading Commission and allows bets up to $500.
[1]http://en.wikipedia.org/wiki/Policy_Analysis_Market