How the Facts Help Predict a Presidential Candidate’s Winning Margin
A new paper from the Harvard-Harris poll finds that, for the first time, voters can accurately judge a candidate’s chances of winning a general election by their own judgment.
The poll shows that the average voter correctly correctly guesses the candidate’s margin of victory by about 3 percentage points, compared to the average guess for the last three presidential elections.
The accuracy rate was just under 30 percent, and was significantly better than the accuracy rate in previous presidential elections, when the candidates were all in the top 10 percent of the polls.
The authors note that their survey of 1,079 registered voters, conducted on August 6-8, shows that Clinton and Trump’s margins of victory were within 1 percentage point of each other.
This means that if you were a voter and you had the chance to guess which candidate had the best chance of winning, you would have correctly guessed that Clinton had a 56 percent chance of securing the presidency.
The margin of error for the two candidates was less than 3 percentage point, and the margin of sampling error was less over 9 percentage points.
The authors attribute this result to voters’ ability to accurately judge the likelihood of winning the election based on their own judgments, rather than relying on the accuracy of the pollsters.
They also point out that the sample size is too small to provide an accurate estimate of the accuracy, since the sample of registered voters included only people who had voted in the last two presidential elections and those who had not yet registered.