Returning the SP:
As the presidential race finally got under way, both the polls and the markets were expecting a Democratic Party victory with the pollsters predicting a vote for Barack Obama nearly a full percentage point higher than the final assessment on the University of Iowa’s Electronic Market.
Historically, the market has got closer to the actual result than the pollsters.
The predicted national two party vote (minor candidates and don’t knows excluded):
Average of the opinion polls at Real Clear Politics- Obama 53.0% McCain 47.0%
Iowa Electronic Markets – Obama 53.9% McCain 46.1%
The probability of victory:
The pollsters’ figures for the predicted vote do not tell us what the probability of victory is for either side but the markets do.
The three major markets operating on the presidential poll finished this way:
- Betfair: Obama 95.0% McCain 5.0%
- Iowa Electronic Markets: Obama 93.6% McCain 6.4%
- Intrade: Obama 93.1 McCain 6.9%
Electoral College votes:
Intrade runs markets on which party will win what electoral college votes in every state.
The final totals predicted in this fashion were Obama 364 to McCain 174