Jay Cost · @JayCostTWS

8th Nov 2012 from Twitlonger

A note on the polls...

This cycle I noted time and again that the polls were non-normally distributed, which suggested that pollsters were sampling different "electorates." My guess was that the polls showing a tight race to a Romney lead in the swing states were correct. Obviously they were not. I had a theory to justify this prediction, but I turned out to be incorrect.

I have been thinking about why I was wrong, and this is the answer I have come up with, at least as of now.

One of my intuitions was that the Democratic non-white vote would not rise very much this year because of the big jump in 2008, in particular in non-competitive states like Illinois, Mississippi, and California. Looking at the hard numbers, that turned out basically to be correct (although the Latino vote looks to have increased modestly).

What I did not anticipate was a steep drop in the white vote. My back of the envelope calculation suggests that the white vote was off by almost 10 million votes relative 2008. [This is the primary reason why Mitt Romney will end up winning fewer votes than John McCain, but have a larger share of the total electorate.]

So, the polls that showed a big Obama edge, often due to a loose likely voter screen, were right for an ironic reason. Turnout was down, suggesting a tighter screen would have been better, but because turnout was down so substantially among whites, the actual electorate looked a lot like more like the broader population than it has in years past (even in 2008). Thus, a loose screen produced the better reflection of the voting public.

A tip of the cap to those who figured it would go the other way. Job well done!

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