Tie scenarios

It's been a slow week here, as I've been spending all my free time watching the Olympics. (Definitely not watching the candidates discuss faith with Rev. Warren.) In my absence, it looks like Obama has resumed a modest post-June slide that has been broken only by his international trip. Absent major scandal, I'd be surprised if there were significant movement before the conventions.

For that matter, I expect the bounces for both parties to be very small, as they were in 2004. With so few undecided voters out there, a few hours of coverage by a few channels isn't going to make a big difference. But I could be wrong, particularly if Obama announces a VP at the convention.

I checked 538.com today, and saw that had an interesting post today about electoral tie scenarios. My simulations indicate a somewhat higher probability of a tie than theirs do (1.2% as opposed to 0.7%). I think this is a result of my belief that public opinion is less volatile than 538's methodology would imply. (Other examples of this phenomenon: They give McCain a 6.4% chance of getting 375+ votes, while I give him a 0.4% chance. Their most likely result has probability 2.2%, while my most likely result has probability 4.7%.)

Furthermore, my simulations give fewer possible scenarios for electoral ties. I just ran 50 simulations of electoral ties, and found that they broke down as follows:

• Gore+NV+NH = Kerry+IA+NV+NM. 29 out of 50 simulations. Obama won the popular vote in 25 of these. I haven't studied the simulations closely yet, but this seems very plausible if McCain strengthens just enough nationally to make the western CO/NV/NM very close.
• Gore+CO = Kerry+CO+IA+NM-NH. 18 out of 50 simulations. Obama won the popular vote in 8 of these. This combination seems to happen when the race remains stable out West, while McCain pulls ahead among the NHers who have always loved him in primaries.
• Gore+CO+NH+VA-MI = Kerry+CO+IA+NM+VA-MI. 3 out of 50 simulations. Obama won the popular vote in all of these. Obama has improved over Kerry in almost the whole country, but not in MI. If there's an important D-leaning state that McCain can pick off, it looks like it might be MI, which is why it's my #1 swing state.
• Other. 0 out of 50 simulations. 538.com does come up with other combinations, like Gore+NH+WV, but I find these implausible, at least unless Robert Byrd is the VP pick. If Obama somehow wins Applachian voters in WV, he will surely also win them in the much harder-fought states of OH and VA.