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EDITOR OF REDSTATE

You Too Can Be Like Former Daily Kos Blogger Nate Silver

Nate Silver has all the liberals calmed down these days. He is the Xanax of the activist left, nervous about Tuesday. In an article HotAir linked to earlier today about rich, white San Francisco residents so upset by the thought of a Romney win they can’t use their home gyms, Mary Katharine Ham found this hilarious quote about a liberal who watched the first debate:

“After I read Nate Silver the other day, I felt better,” Blume said.

It is as if the former Daily Kos blogger who went on to be the lefty pollster du jour at the New York Times is some sort of magician. Actually, he’s not. He’s a smart guy to be sure, but my buddy Sean Davis has a great must read about how you too can be the next Nate Silver with a cheap Microsoft Excel spreadsheet plugin whether or not you’ve ever had a Daily Kos account.

I spent a few hours re-building Nate Silver’s basic Monte Carlo poll simulation model from the ground up. It is a simplified version, lacking fancy pollster weights and economic assumptions and state-by-state covariance factors, but it contains the same foundation of state poll data that supports Nate Silver’s famous FiveThirtyEight model. That is, they are both built upon the same assumption that state polls, on average, are correct.

After running the simulation every day for several weeks, I noticed something odd: the winning probabilities it produced for Obama and Romney were nearly identical to those reported by FiveThirtyEight. Day after day, night after night. For example, based on the polls included in RealClearPolitics’ various state averages as of Tuesday night, the Sean Davis model suggested that Obama had a 73.0% chance of winning the Electoral College. In contrast, Silver’s FiveThirtyEight model as of Tuesday night forecast that Obama had a 77.4% chance of winning the Electoral College.

So what gives? If it’s possible to recreate Silver’s model using just Microsoft Excel, a cheap Monte Carlo plug-in, and poll results that are widely available, then what real predictive value does Silver’s model have?

What might make the difference between the Sean Davis and the Nate Silver model? Well, Silver, in 2008, had access to internal Obama polling that he never disclosed. Maybe he has access to some this time as well.

In other words, it is worth noting to those on the right beating up Silver that the data is shaping his model. He is not shaping the data.

But it is also worth noting that for all the super-special pride accredited to Nate Silver and his predictive powers, you too can do it with a cheap Excel plugin.

Lastly, as a number of people have noted, including Sean Davis in this piece, the big issue this year is whether or not the state polls are wrong. If they are, then Silver is wrong. If they are right, Silver is right. It’s that simple. As Sean notes about 2010

State polling averages were wrong in Alaska (they said Joe Miller would be elected), wrong in Colorado (they said Ken Buck would be elected), and embarrassingly wrong in Nevada (they said Harry Reid would be involuntarily retired). FiveThirtyEight incorrectly forecast the winner in each of those states, perfectly reflecting the inaccurate information contained in the state polls.

Thus, of the five major state races in which polls were wrong over the last four years, Silver only got one right. I’m no baseball scout, but batting .200 when it counts won’t get you into the big leagues, let alone the All-Star game.

COMMENTS

  • chrisinva

    OK. Now that is just funny. I have read a couple of liberal sites where everytime someone tries to mention a poll that is not favorable to Obama — the almost automatic retort has been Nate Silver said…
    It is great to see the truth behind the smoke and mirrors.

  • deltawing

    Silver’s predictions are hopelessly out of touch with what’s going on in the real world. He has consistently shown Romney behind in the national race despite a majority of polls that show the opposite. What the hell? Does he just pick and choose which polls to believe?

    Romney easily has 257 electoral votes right now based on MSM polling. All he needs to do is flip Ohio, Michigan, or Pennsylvania. Alternatively, he can win with New Hampshire and any one of Wisconsin, Minnesota, Ohio, Michigan, or Pennsylvania. There is also the possibility that he could pick up just Iowa and Nevada, in which case it’s tied and Romney wins through the House of Representatives.

    Romney’s odds are probably less than 50% if you believe the state polls, but they aren’t 21%. If the state polls are systematically overcounting Dems (because of early voting, improper likely voter screens, etc), then all bets are off.

  • jaykali

    I definitely agree that Nate Silver is keeping the liberal panic at bay. I mean who can feel panicked when Nate’s giving the prez a 70% chance of winning?!? He is going to look stupid on Nov. 7th.

  • jaykali

    In my personal opinion, I am not trying to be cocky but I don’t see how Obama can win the popular vote. He has to hold Wisconsin & Ohio (maybe narrowly) while also losing the pop vote by at least a point. Democrats haven’t even been arguing that Obama will win the pop vote (altho Nate Silver does) – most concede that but thing that Obama will make it up in the swing states which never happens. If Romney wins the pop vote by at least 1%, he is going to win the electoral college.

  • cowbob79

    The problem that I have Silvers hocus pocus is that he or even some right pundits never take into count that the incumbent very rarely wins when his or her numbers are below 50%. For this reason alone I believe that Nate is wrong. The polling organizations polls this week show nothing more than hope on their end to depress the conservative turn out on election day. look at the internals and they tell all that needs to be told. Romney will be the 45th President.

  • gunnarthor

    You should probably write one of these for every polling and predictive site out there since they all pretty much have Obama winning. RCP has Obama up 290-248 with leads in 8 of the 11 swing states. Talking points gives Obama about a 62% chance, same as intrade. EV.com has Obama already at 299 EV.

  • kentucky

    For the polls in Ohio to be held out as a reliable reflection of the voting population is laughable, unless you think turnout is going to be substantially lower than in 2008.

    Most of the Ohio polls are dramatically overstating the percentage of voters who have voted early if 2008 level turnout is presumed. Some are doing so by as little as 8%, others by over 20%. Almost every poll gives Obama a 15-20% margin among this subset of voters. If you take these polls and weight the number of early voters today (as reported by the Sec’y of State) as a percentage of the total 2008 vote, and do the same for the Election Day vote, the polls show the race is at worst tied, and very often Romney leads.

    To illustrate, Purple Strategies found that 26% of Ohio likely voters had already voted. The data from the Ohio Sec’y of State during the period of this poll, as a percentage of 2008 turnout, was about 16%. Thus if turnout matches ’08, this is an oversample of early voters, and a significant one given that Purple Strategies found that early voters favored Obama by 26%! If you weight the poll to show early voters making up 16% of the total vote, and yet-to-vote voters making up 84% of the total vote, the reported result of a 2% Obama lead becomes a 1% Romney lead.

    Another example is PPP. If the already-voted/yet-to-vote subsets are weighted as set out above, Romney’s performance morphs from a 4% defeat to a 3% victory.

    Same story with CNN, if the reported 40% already-voted finding is correct.

    These numbers are more in line with what one would expect to see if Romney had a small lead nationally. The internals continue to tell a different story than the toplines, and the toplines tell a different story than the hard vote count.

    Count me as cautiously optimistic.

  • jaykali

    Liberals love to pat themselves on the back that THEY are the believers in science and facts, particularly when it comes to things like climate change. They don’t acknowledge that even science, economics, etc. can have flawed models that lead to false conclusions. It’s all ab the models, if Nate’s assumptions built into his models are wrong, his outcomes are going to be wrong. I think most of us here are convinced Romney is leading even tho the polls are tight overall bc the polls where he is behind show a partisan split that is NOT going to work on election day. Idiots like Krugman can call conservatives poll-deniers, but the truth is that you can’t expect 2012 to look exactly like 2008 which was a perfect storm for the Democrats. Times they are a changin’. If Romney wins things in 2016 may not look so rosy, it all depends. We can’t expect it to go the same way, it’s ridiculous that the 2010 elections DID HAPPEN and yet those results are so easily tossed aside by liberals. Historic gains for Republicans. We shall have the last laugh…

  • http://aaroninvestigates.wordpress.com/ constructiveconservative

    At the risk of repeating a cliche….The article proves once again, using Mr. Silver’s case as an example, the fundamental truth addressed in the statement, “garbage in, garbage out”.

  • Darin_H

    I don’t even need Excel:

    Obama in 2008 won independents by 8%. Average of polls showing Romney with a lead of at least 12% (I know it is double digits, but I’m not sure the exact # and am not looking it up for this example).

    If you factor that independents are roughly 1/3 or the electorate then you can take the swing (20% or -8 to +12) and multiply that by 33% giving you a 6.6% swing in the national vote from 2008 – assuming nothing else changes at this time. That is close to Obama’s 2008 margin of victory already.

    Thus we come to my assumption – the electorate will not be the D+7 that we saw in 2008. Any shift away from D+7 = President Romney.

    Thank you and be sure to tip your waitress.

  • rationaldb8

    Personally, I’ll go with the University of Colorado predictions. They’ve been incredibly accurate on a state by state prediction of electoral college results for the past 30 years – 8 presidential elections. Their model isn’t based on polling, but primarily on economics. They update their model with current state by state economic indicators regularly and release their predictions each time.

    For the past several months, they’ve predicted a Romney landslide by the electoral college. Obviously it’s possible this could be the one they get wrong, but they’ve certainly got an excellent track record that’s far better than any polling.

    (speaking of the upcoming Romney landslide, you might enjoy my humorous post Uninstalling the Obama Trojan)

  • freemkts

    I wish Silver stuck to baseball forecasting. If he did he’d say the NY Yankees would win the WS, and the Giants had only about 23% chance of doing the same.

  • Tbone

    Actually, both Romney and Obama each have a 50% chance of winning. After all, there are only two of them.

  • JKnight

    The latest counter to this argument from liberals is that basically so many Republicans left the party and now call themselves independents (but still vote Republican). Thus, in their worldview, it’s obvious Mitt Romney would be ahead with independents.

  • JKnight

    Valid point. He definitely uses too many significant figures.

    More often than not, models will tell you want you want to hear.

  • Jack_Savage

    For some reason, every time I hear the first sentence I laugh out loud. It’s just funny every single time.

  • bk

    If Romney wins, no doubt we’ll start hearing nefarious Deibold-like stories galore, because Nate Silver’s predictions “prove” that Obama won the election fair and square.

  • APA Guy

    Best smack-down of this sideshow Daily Kos phony EVER. The same idiots who bow to the alter of Nate Silver do the same when Paul Krugman writes ANYTHING. They live in a world of delusion…a world that is set to crumble in a few short days.

  • APA Guy

    That, JKnight, is what we call convoluted logic. Independents are leaving Obama, therefore they HAVE to be fringe Republicans. Yeah…RIGHT…it can’t possibly be that Independents have absolutely no use for the guy. As I said above, reality is in store for these clods in a few short days.

  • APA Guy

    Yep…it’s becoming the left’s Linus blankie: “Nate Silver says ______……Now I fel better.” Wonder how they’ll feel Election Day as the votes come in? :)

  • http://travismonitor.blogspot.com Freedoms Truth

    “If you weight the poll to show early voters making up 16% of the total
    vote, and yet-to-vote voters making up 84% of the total vote, the
    reported result of a 2% Obama lead becomes a 1% Romney lead.”

    Brilliant point … it’s even worse than that for Obama, because if he is leading in this poll by much more than rest of poll, AND the “I voted already” is being overstated, that means that the vote liars might not end up voting at all, so it shifts even more for Romney.

    These polls of Obama winning the early vote were a concern, but national ones (Gallup) show Romney winning the ‘already voted’ vote.

    I care not just about Romney winning, but also important if not MORE IMPORTANT THAN A ROMNEY WIN IS AN OUTRIGHT WIN IN THE US SENATE TO GO ALONG WITH IT, without which, Romney will be unable to do much without making deal with the devil (aka Harry Reid).

  • http://travismonitor.blogspot.com Freedoms Truth

    Actually, several layers of crapola in his methodology.

    Another one: Are state polls independent? Getting the co-variance between state polls correct is an impossible task. How much does Florida state poll change correlate with Ohio poll change? Not only is is it doubtful Silver did this right, it is impossible to show in any given election what the right number is.

    Phony precision is one thing. Having ANY probability on it at all without more of a real statistical confidence level is also phony. Assuming a distribution around a poll result is an act of circular logic that assumes something about the sample. Cherry picking polls is a great way to destroy actual confidence levels around what you are measuring.

  • http://travismonitor.blogspot.com Freedoms Truth

    Nate has simply ignored polls he doesnt like, which is a big part of why he is wrong. He also is abusing statistical science, but that’s a separate issue from his absurd bias and slant via poll cherry-picking.

  • lapert

    This is just not true – he doesn’t ignore any polls. There are reasons to think his model may be off but this isn’t one of them.

  • onemoreforthegipper

    An incumbent winning only 47% of the popular vote five days before Election Day is in big trouble. What’s amazing is that 47% of people think the Butcher of Benghazi deserves a second term. God help America.

  • Darin_H

    That’s why I put my assumption near the bottom. Reading is hard!

  • http://www4.webng.com/rickbull/lostlucky/ rickbull

    Steve, you and I must have had math teachers in common . . .

  • http://www4.webng.com/rickbull/lostlucky/ rickbull

    Technically, both Romney and Obama have slightly under a 50% chance of winning (even in a coin toss, there is the possibility that the coin will land on its edge).

  • http://www4.webng.com/rickbull/lostlucky/ rickbull

    47% of our voters couldn’t even show you Libya on a globe. I really wonder if they even know that it exists.

  • The_Rebel

    Here’s an example of how the state polls are systematically over counting Dems. Franklin and Marshall College had a poll in PA released yesterday. They give Obama a 4 point lead, 49-45. What is not shown in RCP or any other blog reporting polls is that they used a D +13 sample, 50-37. When Obama won in 2008 in PA he had only a D +7. If we assume the same turnout in 2012 as in 2008, then Romney is ahead by 2. If we factor the enthusiasm levels this year, the turnout should be somewhat less than D +7, meaning Romney’s lead is even greater in this poll. This is why Romney is going to PA on Sunday.

  • chuckg

    If the Republicans left the party in 2008 by simply staying home and not voting that would be a reason the Dems had a +7 edge in 08. If those who stayed home in 08 return in 12 (which they will…) it doesn’t matter what they call themselves..a vote for Romney is a vote for Romney…and that +7 edge disappears and becomes a +3 D to +3 R on Tuesday….so how do you get a +7 or +8 Dem with millions of Republicans realizing they have very big interest in voting this year–this wipes out any gains in the population increase of hispanics….and how many Dems are doing what Republicans did in 08–staying home?

  • deltawing

    Actually, Silver completely ignores the national polls. His numbers are based entirely on an analysis of state polls. He claims that national polls are more biased than state polls. This is a curious claim, since his own data shows that national polls showed absolutely no bias in 2008, and about the same bias as state polls in 2004.

    http://fivethirtyeight.blogs.nytimes.com/2012/10/31/oct-30-what-state-polls-suggest-about-the-national-popular-vote/

  • lakeshore

    There’s a simpler formula than all of this math. If you want to know who will win any Presidential election, ask one question: are people wanting change, or more of the same. We saw how people responded in 2010 to the “change”. That was a vote against Obama. Another word that matters, especially now is “chance”–as in, “let’s give me a chance”. That would be Mitt Romney. Many of the people who gave Obama a “chance” in 2008 regretted it soon after, and were just waiting to see who might replace him. You have to have an intuitive feel for this, from listening to middle American voices, rather than by over processing statistics from whatever sources, right or left. Remember, the polls are just an imperfect reflection of what average people are actually thinking. I think Romney will do a little better than Bush did in 2004, and electorally be around 300.

  • retrocon87

    luckily we won’t have to be guessing about this crap much longer and will definitely know soon enough whether or not silver’s been totally full of #*&@

  • davesinsanantonio

    No, their world will continue on its delusional way. There is no cure for liberal fantasies except reality, and they refuse to see it or accept it. They will blame everyone but Obummer. They will blame Bush, Romney, racism, transfats, global warming, and rabid squirrels. But, they will not accept reality. So, expect them to find a nut case for ’16 and expect the lap dog press to lie about everything Romney does or says.

  • davesinsanantonio

    I believe Silver is one of those people who start with a conclusion and works backwards to find just the data that “proves” it.

  • davesinsanantonio

    The problem with people like Silver is that he will still be around no matter the outcome of the election. If he is right, he will be touting that forever. If he is wrong, there will be the endless interviews and such where he will explain why he failed, and why he will be right the next time. The libs keep their failures around and treat them like winners. And, the lame stream media goes along because they are libs at heart. I wouldn’t be surprised to keep seeing Obummer ads even after they lose this one big time. And, even worse, we will have to listen to Bite-me on the View and other trash shows, and Moochelle will be telling us what to eat every chance we get. Of course, she will no longer be “proud” of America if it dumps her current husband. I wonder who his replacement will be.

  • davesinsanantonio

    That would account for the Libertarians, they are always “on edge”. Sometimes over it!

  • davesinsanantonio

    That makes more sense that listening to pollsters to me. I think, for whatever reason, people are not always honest with pollsters. The proof is in the voting booth pudding. And until then everything is merely speculation. Remember, there are three kinds of lies: Lies, damned lies, and statistics.

  • funwithknives

    “…the Libs keep their failures around and treat them like winners…”
    To wit: William Jefferson Clinton, proven liar, Seeder of Dresses, Impeached President and dis-barred Lawyer extrordinaire.
    Right now, here in Michigan we are facing 6 ballot proposals, 5 of which are to be placed into our Constitution if they are ‘winnahs’.
    #3 is to place renewable energy mandates of 25% of total output, by 2025 into the Michigan Constitution with no more than 1% rate increases in any year.
    They’re touting Billy-Bob Clinton as an authoritative source of wisdom , on this subject. They’re using ‘his picture and everything’.

  • dpmaine

    The Colorado model is interesting, but you are not 100% accurate with the way you describe it.

    They do not (yet) have a predictive model – meaning, the model (well, models) they have developed have been developed after the fact. This is the first election they will be tested as events happen.

    In most any situation with lots of raw data you can correlate enough data points to create a model which tracks historical precedents and predicts historical events correctly. With enough data points there are often hundreds, thousands, many times millions of models that will correctly predict the outcomes.The trick in making predictions is separating things that influence the results, and things that are noise.

    So to put it this way, after the baseball season is over, you can take the whole stats book, and create a formula that solves the win/loss record for the World Series Championship. In fact, there are probably hundreds of formulas that will get you there. And you can keep adding statistics that make it seem more impressive – the 2nd basemen’s slugging percentage is always higher than the 3rd basemen’s slugging percentage, when the team is home, on Tuesday’s.

    It will be interesting to see how Colorado model pans out, but right now, it’s not a prediction model, it’s an economic model.

  • dpmaine

    Probably true. Interesting though is that the re-elect probability is, what, like 74% according to Nate Silver? People win 1-in-4 bets all the time.

  • dpmaine

    If Romney is ahead by 2, why is going to PA? That’s a solid lead, he should be moving on to another target.

    I think one problem with what are seeing is that all pollsters are having problems with determining the voter mix, self-identification is a very problematic thing right now. Others have pointed out that many solid Republican voters identify as Independent now, and many solid Democratic voters do not identify as Democratic.

  • snappy101

    I think I’m going to see what the Marquette pollers have to say. They are the ones who took all kinds of flack from the Democrats before the election for predicting a Scott Walker recall win in Wisconsin by the correct spread. I mean they nailed it on the money and they were ridiculed and called every name in the book before that Election day.

  • Finrod

    Forcing Obama to defend PA means Obama has less time to shore up Ohio, Wisconsin, etc. Also, a 2pt lead is not a solid lead.

  • Finrod

    Not true. Silver loves PPP (dKos pollster) and hates Rasmussen.

  • lonestar200

    “particularly when it comes to things like climate change” – given that my profession directly deals with this: conservatives have been on the wrong side of science here for quite a while. One could quibble about the models and their predictions – someone could convince me that some given factor isn’t being weighted properly or that another one isn’t yet addressed well, and that our uncertainty margins should be adjusted for *future* predictions….

    But the record of warming so far (faster than we predicted across the board), as well as massive biotic changes already underway, ocean acidification, etc. these aren’t debatable. They’re just happening, and there’s loads of scientific data to show it. Pretending global warming isn’t happening is just flat out ignorant at this point, from a scientific perspective. I don’t mean that offensively, just as a straight statement of reality. The GOP will do itself a great service to quit trying to die on this hill.

  • streiff

    my condolences to you on choosing that dual major in necromancy and phrenology. When you can tell me what is going to happen next weekend, +/- 5degrees, I might take time to pay attention to anything else you have to say.

    Be that as it may, this isn’t a thread about climate change. Stop trying to threadjack.

  • rationaldb8

    Yes, you’re correct – they backcasted the previous elections using the appropriate data for each. I should have said projection rather than prediction. I’ll still bet on their model over the currently schizophrenic polls which in recent years haven’t been very accurate over time.

  • rationaldb8

    Thank you DavesInSanAntonio! I just posted it to my diary with a few additions. I held off posting it earlier so my previous post, America Knows “Leading from Behind” Isn’t “Smart Power” wouldn’t get knocked off the main diary page before folks at least had a chance to see it. I found out the hard way that only one post from each member will show up on that main diary page, no matter when you posted each article. Posting “Leading from Behind” knocked “The Confidently Ignorant President” off, even though I’d posted it late the night before so it had only been up less than half a reading day.

  • rationaldb8

    I pretty much agree with your general gist – but have to say that it’s not an easy thing to create a model that accurate backcasts complicated systems. That’s why the Univ. of Colorado model is so promising. Time will tell, however! I just hope their model actually pans out, and we see a decisive win for Romney, contrary to what so many polls suggest. The xkcd cartoon is a good one, but isn’t really applicable to this issue.