The data are in. It’s time for predictions – with error bands.
Electoral vote: The final polling snapshot is Obama 352 EV, McCain 186 EV. The confidence bands are 68% [337,367] Obama EV, 95% [316,378] Obama EV. (Note added, Nov. 24: The snapshot was not stable. Variance minimization identifies longer periods for averaging, which give a result of 364 EV.)
Bias analysis: I expect cell phone users missing from landline surveys to give Obama a 1% boost. Based on the bias adjustment I gave you earlier, this scenario brings the median to a level that is still within the 68% confidence band above. I make my own personal (not official!) prediction: Obama 364 EV, McCain 174 EV.
Popular vote: The median Obama-McCain margin is Obama +7.0+/-0.8% (n=9, 10/31-11/2). The error bar incorporates assignment of undecided voters. My final prediction is Obama 53%, McCain 46%, third-party candidates 1%.
Individual states: Since it’s directly contrary to the point of the Meta-Analysis, I consider this part to be strictly for fun. Normally, for a specific prediction I would use the mode. However, three states show an exact nominal tie over the last 3 polls plus last week of polling: Indiana (11 EV), Missouri (11 EV), and North Dakota (3 EV). These states must somehow be assigned. North Carolina (15 EV) has a median of McCain +0.5% (n=10). On average, each candidate would get two of these states. This would lead to 352-364 EV for Obama. Based on longer-timescale trends I assign MO, ND and IN to McCain, <del>MO and</del> NC to Obama. (Note: updated to reflect a better algorithm, 9:18am.) The map is given at the end of this post.
Turnout: 135 million. Curtis Gans of American University’s Center for the Study of the American Electorate (CSAE) has released a report estimating voter registration at 153.1 million, or 73.5% of the eligible population. He expects turnout in the range of 132-135 million. InTrade is high on turnout being at least 60% of the over-18 population in the US. Assuming a population of 228 million this suggests 137 million or more votes cast. I use the top of Gans’s range.
Final breakdown: 56 Democrats, 42 Republicans, 2 independents, for a working 58-42 majority. The next most likely outcome is 59-41 if Franken wins (see below).
The probability of Democrats/Independents reaching 60 seats is 1.4%.
Democratic: AK (Begich), NC (Hagan), OR (Merkley)
Republican: GA (Chambliss), KY (McConnell), MS (Wicker).
Too close to call: MN (Franken-D vs. Coleman-R-i), with a tiny advantage to Coleman.
If Chambliss does not receive 50% of the vote, he and Martin will go to a runoff.
Final breakdown: 257 Democrats, 178 Republicans. The error bar is +/-3 seats, making a 68% CI of (254, 260) Democrats and a 95% CI of (251,263) Democrats. This estimate was made using aggregated House polling data from Pollster.com.
Postscript: 3BlueDudes.com has a compilation of 45 projections, one of which is my own. The other 44 projections give a median of Obama 353 EV, McCain 185 EV (SD=27 EV). The 68% range of their predictions is [337,367] EV. The Meta-Analysis encompasses them all.