Tuesday, April 13, 2010
Rasmussen: Generic Ballot Right or Wrong?
The latest Rasmussen poll has Republicans winning on the generic ballot by 9 points (47%-38%). Is Rasmussen right? Could they be even under-doing a Republican romp as Nate Silver suggests they may?
The answer is maybe.
Since 2002, when Rasmussen first asked the generic ballot question, they underestimated, nailed, and overestimated the Republican vs. Democratic margin. As the table above illustrates, Rasmussen's final pre-election poll low-balled the Republican margin in 2004 by 8.2%, but did the exact opposite in 2008, overshooting it by over 4%.
It should be noted that Rasmussen adopted its currently dynamic weighting process in 2006, which helped them perfectly predict the spread between the two parties in the national house vote in 2006. Yet, this same dynamic weighting led to Rasmussen under-predicting the Democratic victory in 2008.
Interestingly, the spread between the two parties on the generic ballot barely budged from April to Election Day from 2004-2008 . That is, Rasmussen's polling was very stable, which can likely be contributed to Rasmussen's weighting by party. Of course, in only 2006 could the stability be seen as a sign of accuracy.
So what does all of this information tell us about Rasmussen's generic ballot polling 2010?
Basically, it may be accurate or it may not be, but it will most likely be consistent.
Subscribe to Posts [Atom]