Interesting front page article in the WSJ today by John Harwood, especially for those of us with a quantitative bend.
The crux of the Harwood’s argument is this: For followers of the political horserace, you might as well ignore the day-to-day polls: "Opinion polls themselves had been getting harder to conduct long before the matchup between President George W. Bush and his Democratic rival, Massachusetts Sen. John Kerry. The reasons range from growing reluctance to participate in surveys to increasing reliance on cellphones rather than the land lines pollsters have long used to ensure demographic and geographic balance in surveys."
The Journal notes criticisms similar to Zogby’s; Namely, that sampling with a disproportionate number of party members — in this case, GOP — will inaccurately skew polls in that direction.
Handicappers of the race should recall that Zogby has won acclaim as the most accurate pollster for the past few years, including the tight 2000 Presidential election. Over the same period, Gallup was predicting a similar-to-today double digit lead for then Governor George W. Bush in 2000.
Despite Gallup’s predictions, Bush lost the popular vote by more than half a million votes.
The Journal notes that "Gallup asks a series of questions first devised decades ago that assigns voting probability to each respondent; it then uses their answers and an overall estimate of voter turnout to identify the likely electorate." (emphasis added)
Several commentators note that Gallup poll internals are tracking the exact same error they made in 2000. The Journal even cites Ruy Teixeira‘s blog Donkey Rising. It is yet another instance of the blogosphere impacting mainstream media.
Here’s an excerpt:
Widely divergent poll results in recent days underscore a paradox of the 2004 presidential race: Despite all the surveys, it may be the toughest election in memory for anyone to track . . .
But this year’s bitter presidential contest has heaped on new challenges. They include an exceptionally close race and a polarized electorate that magnifies the consequence of different polling methods. In addition, unprecedented voter-mobilization drives by both parties make it especially tough for pollsters to say which voters probably will show up on Election Day.
"It makes it harder" to forecast the likely electorate, says Fred Steeper, a longtime pollster for Mr. Bush. In the six weeks to Election Day on Nov. 2, he adds, disparate polls may reflect sampling error and methodological differences more often than shifting opinion. "My advice to the consumer is … the day-to-day reports of polling will exaggerate the changes in this race."
For more on this subject, see Why You Should Ignore The Gallup Poll
Divergent Opinion Polls Reflect New Challenges to Tracking Vote
The Wall Street Journal, September20,2004;PageA1
It Is Not An 11 Point Race
Zogby International, September 07, 2004
Gallup Strikes Again!
Donkey Rising, September 17, 2004
A Few More Thoughts on the New CBS News/New York Times Poll
Donkey Rising, September 20, 2004
Why You Should Ignore The Gallup Poll This Morning – And Maybe Other Gallup Polls As Well
Sep 17, 2004