October 12, 2012
Swing State Polling

If you’re interested in the inside the polls information — e.g.„ not just the who’s ahead and who’s behind information — the NY Times has some great data up from the swing states of Colorado, Virginia, Wisconsin, Florida, Ohio and Pennsylvania. It’s worth checking out. Short version? People like Obama on Medicare and other human benefits programs … but prefer Romney on taxes, the economy and the deficit.

So it should be interesting to see how things unfold.

For the politically geeky, this is fun.

September 26, 2012
On Republican Math

By now, many of you may have seen the stories indicating that Republican activists—like all partisans when their candidate is behind—are urging people not to believe the polls. Instead, we are to believe that the candidate’s internal polls show him to be tied or ahead.

The particular twist that the folks at FOX News and the Romney campaign are putting on this claim is that the “likely voter” models being used by mainstream polling firms are skewed towards the Democrats.

This, as it happens, is quite possible: many people don’t understand that the reports of “who’s ahead” and “who’s behind” that so dominate the news are not, in fact, simple reports of percentages in a sample. Instead, they are estimates massaged from the data. Pollsters look at the data and then add “weight” for the opinions of those deemed “likely to vote” while discounting the opinions of those deemed “not likely to vote.” Such weighting is particularly common if the sample was overrepresented or underrepresented by any important group: if the sample has too many college students by overall percentage of the population, for example, pollsters will unweight their opinion in the likely voter model derived from that sample because college students vote at lower rates than does the general population.

The thing is, almost every likely voter model ever built is weighted in a way that overestimates votes for Republican candidates rather than underestimates it. This is because the kinds of people who tend to vote in higher numbers — white people, college educated, middle class, etc, — tend to be people who vote Republican. By contrast, groups that tend to vote Democratic — minorities, less educated, less well off — tend to vote at lower rates. Thus pollsters, trying to predict the final vote, overrepresent white, college educated middle class people in their estimates while underrepresenting others.

(As an aside, it was just this issue that stopped me watching CNN in 2000: their likely voter model was so skewed towards Bush I couldn’t stand it. I only watch CNN for coverage of emergencies now … although their election night data is really good.)

So is it possible that all the mainstream pollsters have built likely voter models that advantage Democrats? Sure it is is. Have they?

It’s not very likely.

April 27, 2012
Do spring polls matter? Do they tell us who will win the election in November? Umm, not so much …
From Nate Silver, fivethirtyeight.com

Do spring polls matter? Do they tell us who will win the election in November? Umm, not so much …

From Nate Silver, fivethirtyeight.com

October 28, 2011

Do you think this person could be president of the United States?” he asked. β€œIs anybody willing to raise your hand and say β€˜I would be comfortable if he became the next president of the United States?’

Not a hand was raised.


— Finding of Peter Hart, pollster, at a small group discussion among Ohio Democratic, Independent and Republicans about Herman Cain. From the Washington Post.

May 27, 2011
When Polls Matter (and when they don’t)

Early Polls and Presidential Election Outcomes

This is a nice bit of analysis from The Monkey Cage. It links to research that looks at the question of how predictive of election outcomes polls are by how far out from the election we are. You can see the whole report here.

The upshot is: current polls likely mean little, except to the degree that they inform the dynamics of the pre-race: who is able to raise money, who is able to command media attention, and the like.

As I have pointed out before, if you want to know who is likely to win a party nomination for president, early polls can help a lot, at least for Republican candidates: early polls tend to be more predictive for Republicans when it comes to winning the nomination, and less predictive when it’s Democrats seeking the nomination. But for the general election, 300 days out is still a long, long way out.