The Secret Lives of Pollsters
By MARK BLUMENTHAL, Op-Ed Contributor - February 7, 2008 -
http://www.nytimes.com/2008/02/07/opinion/07blumenthal.htmlMark Blumenthal is the editor and publisher of Pollster.com and a polling analyst for National Journal.
POLITICAL pollsters have had a rocky 2008. In New Hampshire, after a final round of pre-election polls showed Barack Obama leading by an average of nine percentage points, Hillary Clinton defeated Mr. Obama by fewer than three percentage points. In South Carolina, the numbers were worse. Pre-election surveys there showed Mr. Obama leading Mrs. Clinton by an average of 12 points. He defeated her by 29 points.
In some of the primaries and caucuses held on Tuesday, things weren’t much better. The final polls seriously underestimated Mr. Obama’s performance in Alabama and Georgia, and Mike Huckabee’s vote in Georgia and Missouri. In California, two polls conducted over the same two-day period before the election yielded diametrically opposite results: one showed Mrs. Clinton leading by 10 percentage points, while the other reported Mr. Obama up by 13 points. In four other states — Illinois, Massachusetts and Connecticut for the Democrats and Alabama for the Republicans — polls showed large ranges of variation.
As the remaining states prepare to cast their decisive votes in this campaign, how are voters supposed to make sense of all the conflicting data?
Unfortunately, when the differences are as severe as they were in California, we can’t. Despite 22 years of experience as a Democratic pollster, I can only speculate about what might be going wrong.
Why? Because so many pollsters fail to disclose basic facts ...... If pollsters disclosed more about how their polls were conducted, we would be in a better position to know which polls are likely to be right, and which ones can be safely ignored.