A Few Thoughts on Nate Silver

By James Kwak

Many people have spilled far more words on this topic than I can read, but I wanted to point out a few things that seem clear to me:

  • As Daniel Engber pointed out, the fact that Obama won (and that Silver called all fifty states correctly) doesn’t prove that Silver is a genius any more than Obama’s losing would have proven that he was a fraud.
  • In fact, Silver appears to have gotten a couple of Senate races wrong, but that still doesn’t prove anything, since his model spits out probabilities, not certainties.
  • To my mind, the crux of the debate was between: (a) people who believe that it is meaningful to make probabilistic statements about the future based on existing data (both current polls and parameters estimated from historical data); and (b) people who believe that there is something ineffable about politics that escapes analysis and that therefore there is something fundamentally wrong, or misleading, or fraudulent about the statistical approach. Silver, through no fault of his own, because associated with (a). To my mind, (a) is right and (b) is wrong because of logic and math, so the idea that one election could have settled the question was crazy to begin with.
  • Within camp (a), there are certainly valid methodological debates, and it’s by no means clear that Silver is the state of the art. Whether, in the last days of an election, he is any better than simple averages is an open question. The value Silver adds or doesn’t add can’t be judged by the final forecast, because one point of his model is to incorporate factors that are not incorporated in current polls (e.g., economic conditions). (Another aspect of the model is to not overreact to short-term trends—but that aspect also largely vanishes by the night before.) So the superiority of the  model, if it is superior, would appear months before the election, not the night before. But that is even harder to verify by ultimate results. Ideally you would have many elections and for each one you would have a Silver forecast six months before and a simple poll average six months before and you would see which had a higher batting average. I would bet on Silver, but we’ll never have enough data to resolve that question.

If the outcome makes people take statistics more seriously and pundits less seriously, that’s a good thing, but it’s not why you should take statistics more seriously.

9 thoughts on “A Few Thoughts on Nate Silver

  1. I followed his analysis most days for the past 6 months or so. His overall mapped varied very little in all that time. His “Now” map varied a great deal (“if the election were held today”), but his “11/6” map was remarkably stable, and correct that far out. That, combined with calling the final outcome correctly of all 50 states, says a great deal.

  2. Is this the place where I could ask Baseline Scenario to suggest:
    a) most important priorities for immediate and also long-term actions in the new administration re the economy? and
    b) names for new top officials in economy posts? How about Sheila Bair for Secretary of the Treasury?

  3. I’ll ditto Erik’s comment.

    To James’ point about the need for multiple elections, I would think Nate has already met that standard with forecasts in 101 state presidential elections and 100 Senate elections in 2008, 2010, and 2012.

  4. Not to mention his Pecota projections for Baseball Prospectus…

    As we learn more about the victory and how it was achieved, we’re also finding out that Silver’s contemporaries are making themselves just at home just as much inside political campaigns as outside. This election was won by new-fangled analytical techniques married to old-fashioned shoe leather. Who woulda thunk it.

    US culture, society, and business seem to reinvent themselves on a continuing basis. Seems it was the time for electoral politics to do the same.

  5. Nate is the man! The more interesting question: Given the odds six months prior, could either campaign look at the data and do anything to change things? If either were more agile and people more responsive, we would have seen more see-saw in the odds. I think I saw this in the Sen Webb race, but otherwise Nate and demography are destiny.

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