DP12220 | Facts, Alternative Facts, and Fact Checking in Times of Post-Truth Politics

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How persuasive are “alternative facts,” i.e., false statements by populist politicians, in convincing voters? How effective is fact checking in countervailing alternative facts? We conduct a randomized online experiment to evaluate the impact of alternative facts and fact checking on knowledge, beliefs, and political preferences of voters in the context of the 2017 French presidential election campaign. Marine Le Pen (MLP), the extreme-right candidate who reached the runoff, regularly used alternative facts in support of her policy proposals, to which mainstream media responded with systematic fact checking. We expose randomly selected subgroups of a sample of 2480 voting-age French to quotes from MLP and/or real facts. The results are as follows. First, alternative facts are highly persuasive. Second, fact checking improves factual knowledge of voters, but does not have an impact on voters’ policy conclusions or support for MLP. Third, providing only the true facts backfires by increasing political support for MLP compared to a control group, although to a smaller extent than alternative facts. Finally, heterogeneity of voters with respect to prior voting choices and prior knowledge is important for the effect of treatments on political preferences.