ESPNGallup on Tuesday released the results of a comprehensive review of its polling methods, in the wake of putrid accuracy in its polls leading up to the 2012 presidential election.
Gallup finished 24th out of 28 polling firms in accuracy predicting the election, projecting Republican nominee Mitt Romney to earn 50 per cent of the popular vote to President Barack Obama’s 49 per cent.
Obama ended up with approximately 51 per cent of the final vote to Romney’s 47 per cent, meaning Gallup was about 5 points off.
To address the disparity, Gallup undertook what it termed as a “thorough” review of the firm’s methods, led by editor-in-chief Frank Newport and Michael Traugott, a political scientist at the University of Michigan. Traugott led a review of polling after the 2008 New Hampshire Democratic primary, in which virtually all polls inaccurately predicted Obama would win.
In its report, Gallup identified four issues to address moving forward:
- Its likely voter estimate: Gallup said that its likely-voter model likely shifted the race 4 points in Romney’s direction. It blamed its “thought given to the election” variable as one that most skewed its polls.
- Regional controls on interviews: Gallup said it underrepresented both the Eastern time zone within the Midwestern and Southern regions, and the Pacific time zone within the Western region.
- Weighting race and ethnicity: Gallup acknowledged that the method in which it asked respondents about their race inadvertently caused them to include more whites and less nonwhites in their final samples.
- Landline phone sampling: Gallup used a “listed landline sample” that its report states was disproportionately older and more Republican. “These differences likely contributed to Gallup’s less accurate vote estimate,” the report says. Gallup said it would go back to a random-digit sample.
As former Obama campaign adviser David Axelrod pointed out on Tuesday, these issues were brought up during the campaign but were met with “met with stubborn resistance from the Gallup organisation.” The Obama campaign sent a memo to Gallup about three weeks before the election, complaining that its likely-voter model was skewed in Romney’s favour.
Two places where Gallup’s review will be tested are in New Jersey and Virginia, where Gallup will poll this year’s gubernatorial elections.
You can read Gallup’s full review below:
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