Each Tuesday, from now until Election Day, we’ll be posting updates on the current Presidential election odds on both Intrade and Iowa Electronic Markets. Last week was another tough week for Mitt, but hopefully the media will change its emphasis to pointing out some of President Obama’s missteps soon, rather than concentrating on the foibles of his challenger.

Iowa Electronic Markets
has two different Presidential markets. One is the winner take all market. In this one, the bettor attempts to predict who will win the election. Currently, the price for Obama in this market is .800. This means that if you bet $80 on the President, and he won, you would receive $100. There is also a vote share market, in which the bettor guesses the two-party share of the vote each candidate will receive. Currently, the price for Obama is .554. That means that if you think that the President will receive more than 55.4% of the two-party vote, you would place a bet on him. So, if you bet in this market, and you bet $55.40 on the President, and he actually receives 51% of the vote, you would lose $4.40.

Intrade also has a winner take all Presidential market. In their market, the price is significantly lower for President Obama, 72.3%. It is sort of unusual for the two markets to differ by this much, since it permits bettors to ‘play the middle’. This means that if you wanted to bet on Romney, you should bet on IEM; if you wanted to bet on Obama, you should bet on Intrade.

Although Intrade doesn’t offer a vote share market, under a system I’ve devised, 72.3% likelihood of victory is about the same as predicting a 54.7% vote share.

This wasn’t a very good week for Romney; as I said at the beginning, with the debates coming up and the campaigns increase in intensity, this may be likely to change.