Does Fact-Checking Deter Politicians?

New evidence points to yes:

During last year’s election, [Brendan] Nyhan and [Jason] Reifler picked nearly 1,200 state legislators in states with active affiliates of PolitiFact, the nonpartisan website based in Florida that seeks to evaluate politicians’ claims and rate their validity. To one-third of the lawmakers, chosen at random, Nyhan and Reifler sent a vaguely threatening letter. It alerted the lawmakers that PolitiFact was monitoring them and speculated about the potential consequences to their careers. … Another one-third of the legislators got a “placebo” letter: It told them they were part of a political-science experiment “studying the accuracy of the political statements made by legislators,” but no more. The final one-third got no letter.

At the end of the election, the researchers looked at the politicians’ record. How many had been called out for lying, either by their state’s PolitiFact affiliate or in a news story? The results were impressive: The politicians who didn’t get reminder letters were more than twice as likely to be criticized for inaccuracy than those who did. “Our results indicate that state legislators who were sent letters about the threat posed by fact-checkers were less likely to have their claims questioned as misleading or inaccurate during the fall campaign—a promising sign for journalistic monitoring in democratic societies,” the researchers concluded.