When New Hampshire voters cast their ballots in today's primary election, the candidates won't be the only ones tested by the results that emerge out of the the Granite State. Political pollsters will also find out how reliable their predictions turn out to be.
Polls are supposed to provide an unbiased, authoritative view of the state of an election, but the strength of the reputation of any polling firm is the accuracy of its data. Results of elections in recent years have tested those reputations.
Gallup, one of the most trust political polling organizations, wrongly picked
Republican presidential candidate Mitt Romney to emerge victorious over incumbent President Barack Obama, and Gallup wasn't alone.
Last week, the
Des Moines Register/Bloomberg Politics poll
released a day before voting incorrectly predicted the outcome of the Republican presidential caucuses. Similar polling mishaps occurred abroad in national elections in the
Polls aren't simply a predictive measure of who will win an election. They can influence media coverage of competing campaigns, especially given that news organizations often focus on the horse race in day-to-day coverage. Candidates who perform well in polls tend to get more attention from voters as the media spotlight focuses on who's ahead.
Polls even determined who could and couldn't participate in recent debates when the Republican field was too large to accommodate all of the candidates on the stage.
Given how important survey data are to election dynamics, why is it that polls occasionally miss the mark on major elections, even when accounting for their margin of error? What are the underlying issues facing polling firms as an industry?
Why Betting Markets and Polls Don't Agree