Bettors on Intrade, the betting website that routinely sells political futures, are predicting a 79% likelihood that Republicans will take over the House on November 2: bets on the GOP to control the House are now selling at $7.87, and, since Intrade sells bets between $0 and $10, that means the broader market consensus of Intrade bettors has settled on a price correlating to 78.7% likelihood.


Bets pay out at either $0 or $10; if you buy this $7.87 bet, and the GOP does win control of the House, you'll profit $2.13. About as many Intrade bettors think that bet is worth it as do not.

Intrade has been pretty accurate in recent election years. From an article by Leighton Vaughn Williams in the November 26, 2007 edition of The Polling Report, a well-read political polling publication:

Indeed, by 2004 the Intrade market model went stratospheric in predictive accuracy as the market favorite won the electoral votes of every single state in that year's U.S. presidential election. Meanwhile more than one respected pollster and analyst called the race for John Kerry as late as election day itself...

Intrade followed up in 2006 when the market favorite won each and every Senate seat up for election. Moreover, in large part the stronger the favorite, the bigger was the margin of victory.

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