How I Think About Presidential Elections Forecasts

Apr 2 '12

Nate Silver’s newest critique of presidential election forecasting models has been making the rounds.  He was kind enough to publish my response to his critique late last week while I was traveling, so I want to highlight it now.  The essence of my response is this:

* Undoubtedly these forecasting models could be improved in various ways.  I agree with several of Nate’s specific criticisms.  (Thus, contra Jon Bernstein, I don’t think I’m “giving the models a pass.”)

* The models — despite their limitations — rarely predict the wrong winner, so the lay consumer of these models will not be grossly misled most of the time.  By lay consumer, I mean someone interested enough in politics to care who wins the presidential election, but not much interested in “mean squared error” and other commonplaces of the “nerdfight.”

* Most political science knowledge about the economy’s role in elections, the effect of campaigns, and voter behavior does not come from forecasting models.

* There is no easy way to separate the effects of the economy and the campaign — a point I made previously.

Although I am not a forecaster, I’ve been dabbling with a simple forecasting model as part of the book on the 2012 election.  I will have a bit more to say about this subject in the weeks ahead.