A very well-written report at the Huffington Post details how a few decisions by Gallup administrators caused the venerable polling company to miss key pockets of support for President Barack Obama in the run-up to last November’s presidential election.
Going into Election Day, Gallup had Mitt Romney leading Obama 49-48, but the actual result was 51-47. According to analysis by HuffPost, the reason for the bad call was because Gallup’s polling methods failed to keep up with how Americans are using their telephones. This is potentially a huge problem because calling via telephone is the primary method for contacting people for public opinion polls.
Since the number of people screening calls by using unlisted landlines and/or cell phones has risen dramatically over the last few years, polling firms who fail to find a way around the barriers run the risk of missing large segments of voters who are avoiding unsolicited calls.
It just so happens that people using unlisted numbers only (i.e. not cell phones as well) planned to vote for Obama last year by a margin of 58 to 36 percent. But because Gallup’s methodology didn’t correctly measure this subpopulation, the company never got a chance to put this data in their polls. Consequently, Gallup’s opinion polls did not accurately reflect the intentions of the voting public which ultimately influenced who won the presidency.
Gallup is no stranger to embarrassing poll predictions. The famous “Dewey Defeats Truman” headline from 1948 was based on polling data that stopped being collected two weeks before Election Day. The thought was why keep polling if the predictions haven’t changed? Of course, that decision didn’t account for the voters who broke late for Truman and made the false headline iconic.
Gallup rebounded from the fiasco to become arguably the world’s most reliable polling agency. As the process of regaining that crown unfolds, this new breakdown is a good reminder to heed the words of the Gipper – “Trust, but verify” when it comes to public opinion polls.
CFIF on Twitter
CFIF on YouTube