Q+A: Hit political blogger Nate Silver on future of predictive modeling

Fri Nov 9, 2012 4:16pm EST
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By David K. Randall

NEW YORK Nov 9 (Reuters) - Nate Silver is an oxymoron come to life: the famous statistician.

After successfully calling the Electoral College results in all 50 states ahead of the U.S. presidential election, Silver, the man behind the popular FiveThirtyEight blog, has quickly become a symbol of the new power of data in politics.

Television pundits across the political spectrum praised his accuracy on the night of the election. His book, "The Signal and the Noise," about the science of prediction, shot up to number two on Amazon.com.

Silver spoke with Reuters Thursday evening. Here is an edited and condensed version of the conversation.

Q: Some of the more established polls this year had some of the worst results. Why do you think that was?

A: I think pollsters have to get back to the basics here. Do you have a poll that is actually calling everyone? Some of the polls that didn't include cellphones had bad years and that's what you would expect. If you aren't taking a representative sample, you won't get a representative snapshot. Polls on the Internet, like Ipsos, and those like it did pretty well. We are living our lives more online and you need to have different ways to capture that. (Ipsos is the polling partner of Reuters. A report by Fordham University ranked Ipsos/Reuters first of 28 polling organizations in accuracy of final, national pre-election estimates.)

Q: Before the election, you were criticized by some politicians and pundits who said the race was much closer than what your model suggested. Where was the discrepancy?

A: It helps to have a set of rules that you set up. You have to look at the data in a consistent way and an unbiased way and not be fooled by the noise associated with polling. So many people were distracted by the fact that you had polling firms that had outliers, whether from error or poor methodology. The outlier polls got the headlines, whereas the consensus was clear that Obama had a lead in the swing states.   Continued...