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# Never Mind the Models, Here's Some Data

Posted: 10/30/2012 10:03 pm

So, at the end of a day when Twitter was alive with the sound of pundits railing against poll averages (well, one poll average or even one poll averager in particular), I thought I'd try this.

I've simply taken every poll in nine battleground states over the last two weeks from Pollster's data base, converting the reported result to a two-party result. The states are CO, FL, IA, NC, NH, NV, OH, VA and WI. I've then made a graph with each data point covering area proportional to the sample size of the poll, stacking the polls on top of one another, to give a visual sense of where the weight of the evidence lies; I rounded the two-party results to make the vertical stacks. The labels indicate the state.

No house effects. No modeling. Just the data.

The precision-weighted average of these 110 polls (yes, 110!) is 50.6 percent two-party vote share for Obama, with a margin of error of just +/- 0.35 percentage points. That is, given these data, we're extremely confident Obama is polling north of 50 percent, at least averaged over two weeks of polls across these nine states.

99.97 percent sure.

We're not making this stuff up.

Obligatory tech notes: "Precision" = 1/variance; the variance of a proportion p estimated with n observations is p*(1-p)/n. A precision-weighted averaged (PWA) of the polls is formed by summing the poll results (each weighted by its precision) and then dividing by the sum of the poll-specific precisions. The precision of the PWA is the sum of the poll-specific precisions. The variance of the PWA is the inverse of the summed precisions. The standard deviation is the square root of this variance; the MOE is plus or minus 1.96 standard deviations. The probability that Obama's PWA is above 50 percent is the area under a normal density lying to the right of 50 percent, where the normal density is centered at the PWA (50.62 percent) and has standard deviation 0.1775 percentage points.

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HUFFPOST SUPER USER
when does the greed stop?
11:05 PM on 10/31/2012
Here’s a couple examples of Rasmussen polling’s evident blindness to reality.

● In the final weeks of the 2010 governor’s race in California, Rasmussen’s results suggested, using more polling “data” than anyone else, that the race was a toss-up. Right up to until Election Day, Rasmussen flooded the media with the view that Meg Whitman was going to pull off one of the greatest upsets in US voting history. So what actually happened when voters went to the polls? Whitman lost to Jerry Brown by 13 points. This is despite the \$140,000,000 of her own money she used to lather the airwaves with advertising. This was not a “close race” or “tossup”—it was a slaughter.

● Rasmussen also had an apparently out-of-thin-air rosy view of Sharron Angle’s Senate candidacy the same year in Nevada. If he had set out to stir the chattering classes to accept the possibility of Harry Reid’s defeat, he sure got that to happen. Press organs from coast to coast were all eager to participate in the “scoop” of Harry Reid, the Majority Leader of the US Senate, losing his seat. Yet once again, Rasmussen’s polling proved to be entirely off the rails. Reid beat Angle 51% to 44%. Not even close.
BlackisWhite
GOP..Compulsive liars enriching the 1%
06:08 PM on 10/31/2012
Don't believe this does away with "house effects" at all. They are just buried within, and while the data still show a statistically significant edge for the President, the key issue is whose polls have the weighting of the voters for each party set correctly. This is just another way to look at the data, but for those interested the Princeton site by Sam Wang, Nate Silver's 538 blog, and Electoral Vote.com all combine and aggregate poll results in order to make their assessments. All show the President with projected counts of electoral votes of 285 to 300+. The issue with Gallup and Rasmussen is how they are weighting the composition of the electorate or in their Likely Voters screen (Gallup). It is still possible they are correct, but I think both have a "finger on the scale" that is pushing Romney to look stronger that he is. The election results will tell the story...
HUFFPOST SUPER USER
wgbastos
04:56 PM on 10/31/2012
Anyone notice the last time Fox came out with a poll was October 9th?

May God illuminate the American people on the 6th.
Lets hope Americans will want to stay on course with a more fair and just society instead of going back to the warmongering neocons, greed and selfishness.
We all know what happened when we chose Bush again. The second term was full of nice things, from Katrina to the melting of the Economy
HUFFPOST SUPER USER
chuckfox2
One man with courage is a majority.
07:03 AM on 11/01/2012
Interestingly, I jumped over to Faux News and on their front page found this little tidbit.

"With less than a week before the election, the race for the White House is dead even: Barack Obama and Mitt Romney receive 46 percent each, according to a Fox News poll of likely voters."

In the face of polls showing that their candidate is losing, Faux News puts up a brave front and claims a tie.
rvcrane
04:11 PM on 10/31/2012
The Princeton Election Consortium has a record as the most accurate poll analysis. Yesterday, they have 93-97% chance for Obama's reelection. (They are offline today, probably because of the storm.) This is 93-97% chance of continuing the improvements for America since the horrible Bush years. We must insure that the chances of Obama's reelection are 100%. We need to work to counter the lies and exaggerations of the Romney campaign. We need to work even harder at getting people to the polls. The more people who vote, the better the chances for Obama and America.
TeaPartier
Go Steelers! Go Pens! Go Bucs!
04:06 PM on 10/31/2012
Problem is, there is "modeling" inherent in the data because each of the polls is weighted. And the OVERWHELMING majority of those polls figure a very heavy Dem turnout, that mirrors what we saw in 2008, which just ain't gonna happen.
03:44 PM on 10/31/2012
nicely done... what would it look like if you adjusted the input polls to the assumption that the turn-out for the two parties will be about equal (give or take 1%) rather than heavier for Dems... numbers are fun that way.
03:20 PM on 10/31/2012
You can read the frustration in the written words of Willard Romney supporters. They know how foolish they look now after REPUBLICAN Senate candidate Richard Mourdock gave his rape endorsement speech. It's almost over. John McCain is having a heart attack. So close, yet so far John. It's not too late to vote for President Obama, John.
03:16 PM on 10/31/2012
I can't wait to tune into Fox the day after Obama wins. The republican comedy team of Willard, John McCain and Sarah Palin will be depressed for a month. It’s almost over. No more Mitt, Flip Flop. John McCain could then crawl back into his hole again.
HUFFPOST SUPER USER
bckrd1
04:25 PM on 10/31/2012
Please people, do not count the chickens yet. I am a firm believer in the statement "never underestimate the stupidity of the American people". What we have to hope for is a Democratic base that realizes what is truly at stake here and it ain't jobs. It is the future of this country. We will either go forward or go backwards. If we turn out in force to reject the extremist Republican agenda we just may be able to keep Obama in the White House. I also would not expect the decision to be made on the 6th. With voting machines in these swing States being owned by Romney companies, which is what I am understanding, there will be some highjinx going on. I am afraid of the way the Republicans have been trying to rig this election and they will do anything they can to lie, cheat and steal their way to the Presidency. Maybe that is why Romney is lying with such abandon. He knows the machines are already rigged to give him the election.
HUFFPOST SUPER USER
dopper0189
06:01 PM on 10/31/2012
Nope, they'll just say Mitt was a true conservative, and Obama won with voter fraud. They'll be screaming no compromise because 2014 is right around the corner. That is their modus operandi.
03:13 PM on 10/31/2012
Willard will never win. Nobody wants a fast talking used car salesman for President.
HUFFPOST SUPER USER
Richard Steuland
Far left
03:13 PM on 10/31/2012
I dislike the Republican Party because they do not represent a nation that is forward thinking and inclusive. Look at all the groups that their followers are a war with and you just think yuck and ick.
01:51 PM on 11/01/2012
My husband put it best when he said, "The difference between Democrats and Republicans is that Democrats want to believe that people are inherently good, while the Republicans believe that all people are basically bad." He's right.

Obama/Biden ~ 2012
03:08 PM on 10/31/2012
It's a shame that we may have to put up with another year of the same old crap. There are so many lies going on TV and other Media. It is sad that most people listen to these political advertisements and that's how they decide who to vote for. Personally, things have not been good for me. There are so many questions about Obama and he just refuses to answer or show proof. Why? Also, there is the matter of Obama 2016, has anyone watched this movie about Obama's life. Please people, If you don't look into the past of both men running. Stay home from the polls. As far as Birth Control & Abortion women will do whatever they think is best, as will gays. It is really no business of the Government. All I ask is do some research before choosing our President.
HUFFPOST SUPER USER
bckrd1
04:29 PM on 10/31/2012
You do realize the movie "2016" was made by someone who hates Obama right? That is not based on facts. Just because it is a movie doesn't make it true. You can make Mother Teresa look like a street walker if you do wanted to. The movie is Repbulican propaganda and nonsense.
HUFFPOST SUPER USER
jerdan25
04:42 PM on 11/03/2012
This is why its so hard to discuss any rational with these GOPers the take everything as gospel and swallow it hook, line and sinker, everything to them is black or white.
HUFFPOST SUPER USER
ATLiberal
WINNING!
05:33 PM on 10/31/2012
What questions? What proof do you need that is relevant to being President? People have watched Obama for 4 years. There is plenty to judge him on. That is what is happening.
HUFFPOST SUPER USER
SCOTUS13
speakingtruth2power
03:06 PM on 10/31/2012
I have zero doubt that most voters will vote for Obama but I have little faith in some of the tallies.
HUFFPOST SUPER USER
gvalencia05
02:51 PM on 10/31/2012
on the chart if the blue is 50.6 then what is the grey? hmm undecided maybe so that gives romney what anemic amount?
12:05 AM on 11/01/2012
Blue is not 50.6. 50.6 is what Obama's share of all 110 polls comes to. Grey is just all those polls which shows a tie. (for example a poll which shows 45-45, 48-48, 49-49 etc.)
02:49 PM on 10/31/2012
This is too complicated for the republican minds. You know how the are with facts - they always FOX it.
HUFFPOST SUPER USER
ThePelton
Never underestimate the power of Human stupidity.
03:11 PM on 10/31/2012
"Foxing" is fungus attacking paper.
05:19 PM on 10/31/2012
Just the FIX for those Romney binders.
02:48 PM on 10/31/2012
Romney with his LYING has a conducted a campaign WITHOUT HONOR and INTEGRITY that no self respecting American should be supporting. If they do then they are also without honor and integrity.