Nate Silver grades polling firms based on their performance during the midterms and sends Rasmussen packing.
On Tuesday, polls conducted by the firm Rasmussen Reports — which released more than 100 surveys in the final three weeks of the campaign, including some commissioned under a subsidiary on behalf of Fox News — badly missed the margin in many states, and also exhibited a considerable bias toward Republican candidates.
Survey USA, Quinnipiac and YouGov all did pretty well.
You have to wonder about the extent to which faulty polls influence the outcome of an election and are intended to. Silver doesn't exactly raise that issue but he does take Rasmussen to the woodshed for being so wrong so consistently and so blockheadedly.
Rasmussen’s polls — after a poor debut in 2000 in which they picked the wrong winner in 7 key states in that year’s Presidential race — nevertheless had performed quite strongly in in 2004 and 2006. And they were about average in 2008. But their polls were poor this year.
The discrepancies between Rasmussen Reports polls and those issued by other companies were apparent from virtually the first day that Barack Obama took office. Rasmussen showed Barack Obama’s disapproval rating at 36 percent, for instance, just a week after his inauguration, at a point when no other pollster had that figure higher than 20 percent.
Rasmussen Reports has rarely provided substantive responses to criticisms about its methodology. At one point, Scott Rasmussen, president of the company, suggested that the differences it showed were due to its use of a likely voter model. A FiveThirtyEight analysis, however, revealed that its bias was at least as strong in polls conducted among all adults, before any model of voting likelihood had been applied.
Some of the criticisms have focused on the fact that Mr. Rasmussen is himself a conservative — the same direction in which his polls have generally leaned — although he identifies as an independent rather than Republican. In our view, that is somewhat beside the point. What matters, rather, is that the methodological shortcuts that the firm takes may now be causing it to pay a price in terms of the reliability of its polling.
