I would rephrase as, “Reasonably well performed polls taken in groups don’t need corrections.”

Presumably the polls that provided the data set were good (or at least balanced for error) and therefore a meta-analysis provided the necessary power to discern reality. A meta-analysis won’t correct for situations where the pollsters are consistently off. Nontheless, there’s no question that poll aggregation at the very least will minimize built in errors.

Also, a meta-analysis given the current polling group could still end up being wrong in situations where there’s still not enough statistical power to detect a difference or deal with voting problems (such as Floridao 2000).

AAF – I’ll think about how to label these graphs more clearly.
1. Yes. That’s why I added “Oct. 1″ and “Nov. 1.”
2. Yes, it’s useful prospectively, and perhaps also to identify campaign turning points.
3. Not yet, though it’s a good idea.
4. This graph shows the SD of the last N polls, where N is on the horizontal axis. I could have plotted date horizontally, but it seems clearer to me in its present form.

Why don’t you give Nate Silver a call, get him to promise to post the transcript, and then hurl insults at him? That would help raise your visibility.

I’m kidding, of course- you are the anti-Ziegler.

A few questions:

1. The X axis on the first graph, labeled date, is in numbers — are those the numbered-day of the year? It’s a bit confusing because they also happen to be roughly the range of EV’s we were moving through during that period.

2. To my untrained eye, this looks like the kind of analysis that can be used predictively, before an election. Is that right? Or is it really only useful after the fact as a post-mortem analysis?

3. Did you back-test it against 2004 and whatever other samples you have?

4. The graph you show for Missouri is interesting — is it a snapshot, analyzing on election day how standard deviation is affected by how far back you go in including polls, or is it showing how the standard deviation would have looked over time if on each day during the campaign you had included X days of polls?– and did you do the same thing for the national race?