Why is there such a discrepancy between the Intrade and IEM numbers on Obama vs. McCain?

Question

In the prediction markets I follow, Intrade and the Iowa Electronic Markets, the "spread" between the two presidential candidates is substantially different: about 52-48 at Intrade and 60-40 at IEM (Obama the higher number in both cases. Why is there a very slim margin at one prediction market but a relatively large one at (20 points) at another?

Answer 1

In the privacy of the voting booth most red blooded Americans will pull the lever for McCain. Deep down we just trust him more.

Answer 2

The buy/sell chart at IEM is at 51 Obama 47 McCain for buys.

Hit last price on this chart on EIM. http://iemweb.biz.uiowa.edu/pricehistory/PriceHistory_GetData.cfm

That usually tracks closely with the Intrade although EIM sometimes reacts a little more slowly than Intrade.

There were a few days last week when McCain was up in the InTrade market by a few points and IEM never reflected it.

Maybe there are more gamblers than B-school types on InTrade.



I've been tracking the IEM since the late 90s on lots of topics. In the last two presidential elections, it was closer than any polls.

But that was only at the end, not during the campaigns.

It wouldn't be useful for the campaigns to use for planning and strategy.

Answer 3

One is bull chit and the other is ? but who knows?

common sense shows McCain with a slight edge..but who knows as

it depends on how many votes the Dems or Repubs can crook?

Answer 4

They are run by the Democrats

Answer 5

Don't know, but they both got the right man on top!