Taking Nate Silver With A Very Large Grain Of Salt

He's #1 on the list of people whose reputation will be in tatters after the oncoming Mitt Romney landslide.  Coming off a very good 2008 prognostication season (49 of 50 states accurately predicted, in a season where the result was a fait accompli) that earned him a gig at the New York Times, Silver has been consistent in predicting an Obama 2012 victory, even in the face of the rapid post-debate poll swing towards Romney.

Democrats have been clinging to his stats and story-lines the way a scared villager clutches a sacred talisman during a storm, but Bob Krumm tells us their wonder boy is nothing of the sort:

Eleven days before the election he predicted that there was a 70% chance that Republicans would gain less than 60 seats. They won 63. That alone should be enough to remind observors that there shouldn’t be so much certitude about Silver’s 70% predictions a week and-a-half away from a vote.


Apparently, Silver's modeling leans heavily on one single metric: - the spread between candidates. and especially on the spread in state level polling. Frumm points out the flaws as related to 2012:

The incumbent’s level of support, not the spread, is the most important metric in a re-election race. That is because it tells you how safe the incumbent is from the effects of a last-minute surge. On that metric, Barack Obama is not safe at all. Since at least 2010, when the creation of Obamacare led the news, Barack Obama has struggled with his support, only briefly breaking the 50% barrier.

Does this look like a guy with a 70% chance to win-re-election?

Rasmussen shows that for a long time well over 40% of the electorate has strongly disapproved of the President, but only about 30% now strongly approve. Neither the support for the incumbent nor the strength of it appears to be a metric in Nate Silver’s model. Therefore, the over-reliance on the spread as a predictor of success makes for a model that doesn’t account for hard ceilings and soft support. If you were a well-funded challenger, where would you rather be two weeks before an election: 4 points behind an incumbent stuck at 47%, or 2 points behind an incumbent at 49? Even worse for Obama, is that he is stuck at 47 and already behind.


Is Silver a blinded partisan, or an earnest guy who concocted complex mathematical models around an obvious election result, which appears more and more to be a one-time electoral anomaly?

Either way, his time on the top of the numbers game is almost up.  But like all failed liberal icons, the Left will keep him on a pedestal, and he'll make a fortune on the talk shows as "the guy who predicted the 2008 landslide".  Especially when they need him to make wild, unrealistic predictions about 2016...