The Nate Silver Backlash: Every betting market agrees Sarah Mitsy Crushed in Electoral Vote Result

http://www.washingtonpost.com/blogs/ezra-klein/wp/2012/10/30/the-nate-silver-backlash/

The Nate Silver backlash


Posted by Ezra Klein on October 30, 2012 at 3:14 pm

"It seems to happen every few weeks. The race tightens or widens or simply continues on exactly as it’s been, and some pundit or reporter declares it a staggering humiliation for the burgeoning world of election quants.

Niall Ferguson took his turn at bat in early September. “The economy is in the doldrums,” he wrote. “Yet the incumbent is ahead in the polls. According to a huge body of research by political scientists, this is not supposed to happen.”

Actually, according to a huge body of research by political scientists, that was exactly what was supposed to happen.

After the first debate, David Frum stepped up to the plate. “Political science proclaims, ‘debates don’t matter,’ ” he wrote. “After this election, we may need to retire a lot of political science.”

Actually, “political science” never declared debates don’t matter. A political scientist — George Washington University’s John Sides — had reviewed the evidence and written that  “when it comes to shifting enough votes to decide the outcome of the election, presidential debates have rarely, if ever, mattered.”

That was true then. It’s true now. It will be true if Mitt Romney wins the election (saying something has “rarely, if ever, happened” does not mean it cannot happen, as a look at the rather unusual weather outside your window will prove). And it will be true if President Obama, as continues to look slightly likelier than not, wins the election.

Which brings me to the backlash against Nate Silver.

Before we get too deep in the weeds here, it’s worth being clear about exactly what Silver’s model — and that’s all it is, a model — is showing. As of this writing, Silver thinks Obama has a 75 percent chance of winning the election. That might seem a bit high, but note that the BetFair markets give him a 67.8 percent chance, the InTrade markets give him a 61.7 percent chance and the Iowa Electronic Markets give him a 61.8 percent chance. And we know from past research that political betting markets are biased toward believing elections are more volatile in their final weeks than they actually are. So Silver’s estimate doesn’t sound so off.

Moreover, Silver’s model is currently estimating that Obama will win 295 electoral votes. That’s eight fewer than predicted by Sam Wang’s state polling meta-analysis and 37 fewer than Drew Linzer’s Votamatic.

So before we deal with anything Silver has specifically said, it’s worth taking in the surrounding landscape: Every major political betting market and every major forecasting tool is predicting an Obama victory right now, and for the same reason: Obama remains ahead in enough states that, unless the polls are systematically wrong, or they undergo a change unlike any we’ve yet seen in the race, Obama will win the election.

There’s no doubt about that. Real Clear Politics, which leans right, shows Romney up by 0.8 percent nationally, but shows Obama up in Ohio, New Hampshire, Iowa, Nevada, Wisconsin, Pennsylvania and Michigan. Romney is up in Florida and North Carolina, but note that his lead in Florida is smaller than Obama’s lead in Ohio. And RCP shows Colorado and Virginia tied. Pollster.com, meanwhile, shows Obama leading by a point in Colorado and Virginia and the race tied in Florida.

It’s important to be clear about this: If Silver’s model is hugely wrong — if all the models are hugely wrong, and the betting markets are hugely wrong — it’s because the polls are wrong. Silver’s model is, at this point, little more than a sophisticated form of poll aggregation.