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Saturday, November 1, 2008

And then again maybe not

Following up the Zogby announcement of McCain leading for Friday in its polling, gallup has released its tracking polls showing a 10 point Obama lead. Once again, these two polls cannot both be correct. More results come from Rasmussen who says that the difference is 5% and from TIPP which gives Obama a 4.5% lead. Needless to say, three days before the election, one would hope that the polls would agree.

The amazing thing to me is that the polls are not even close. A ten point lead for Obama and a one point lead for McCain are not capabale of being conformed statistically. The four polling organizations in question plus Hotline (Obama plus 7) and Battleground (Obama plus 4) are all over the map. Nevertheless, they are respected polling organizations. We are not even including the pollsters whose bias is consistent like CBS (which usually seems to have Obama leading by 5 or 10% more than everyone else).

We can throw out Zogby and Gallup as outliers and stick to the 4-7% spread of the remaining four, but that seems wrong to me. There is no reason to assume that either Gallup or Zogby is in error. Obviously, one of them is, but who knows which one.

One thing this dilemma with the polls makes clear: even the exit polls on Tuesday will be far from perfect. We all remember how Kerry won last time according to the early exit polls. We will just have to wait for the actual election results to come in.

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