The study from researchers at Ohio State University finds that fake news probably played a significant role in depressing Hillary Clinton's support on Election Day. The study, which has not been peer-reviewed but which may be the first look at how fake news affected voter choices, suggests that about 4 percent of President Barack Obama's 2012 supporters were dissuaded from voting for Clinton in 2016 by belief in fake news stories.
Richard Gunther, Paul A. Beck and Erik C. Nisbet, the study's authors, inserted three popular fake news stories from the 2016 campaign into a 281-question YouGov survey given to a sample that included 585 Obama supporters — 23 percent of whom didn't vote for Clinton, either by abstaining or picking another candidate (10 percent voted Trump, which is in line with other estimates).
Here are the false stories, along with the percentages of Obama supporters who believed they were at least “probably” true (in parenthesis):
Clinton was in “very poor health due to a serious illness” (12 percent)
Pope Francis endorsed Trump (8 percent)
Clinton approved weapons sales to Islamic jihadists, “including ISIS” (20 percent)
Overall about one-quarter of 2012 Obama voters believed at least one of these stories, and of that group 45 percent voted for Clinton. Of those who believed none of the fake news stories, 89 percent voted for Clinton.
This alone does not prove that fake news made a difference, of course. A recent Princeton-led study of fake news consumption during the 2016 campaign found that false articles made up 2.6 percent of all hard-news articles late in the 2016 campaign, with the stories most often reaching intense partisans who probably were not persuadable. And it wouldn't be surprising if Obama voters who weren't reliable Democratic supporters were more apt to believe fake news stories that affirmed their decision not to vote for Clinton.
So the researchers sought to control for other factors such as gender, race, age, education, political leaning and even personal feelings about Clinton and Trump using multiple regression analysis, a method to measure the relative impact of multiple independent variables. According to the researchers, all of these factors combined to explain 38 percent of the defection of Obama voters from Clinton, but belief in fake news explained an additional 11 percent.
For those defecting from Clinton, believing fake news had a greater effect than anything except being a Republican or personally disliking Clinton. Obama voters who believed one of these fake news stories “were 3.9 times more likely to defect from the Democratic ticket in 2016 than those who believed none of these false claims, after taking into account all of these other factors,” the researchers write.
“We cannot prove that belief in fake news caused these former Obama voters to defect from the Democratic candidate in 2016,” they write. “These data strongly suggest, however, that exposure to fake news did have a significant impact on voting decisions.”
Exactly how that translates into raw votes and whether it swung the election is the big question — and the one that seems to preoccupy Trump. It's difficult to know how fake news played specifically in the three states that delivered him the presidency: Michigan, Pennsylvania and Wisconsin. But the fact that Clinton lost each of these divisive states by less than one percentage point means that even a slight impact by Russia and/or fake news — or even then-FBI Director James B. Comey's announcement about Clinton's emails or some other factor — could logically have changed the result.
But we can use this study to glean clues and even rerun a hypothetical 2016 election. The Washington Post's polling director, Scott Clement, ran a predictive probability analysis using the OSU team's data and compared the existing 2016 election to a hypothetical election in which these fake news stories didn't exist. The result: Clinton lost 4.2 percent more of Obama's votes in the race with fake news vs. the hypothetical race without it.
If we multiply that 4.2 percent drop-off by Obama's 2012 vote share in the three key states that delivered the presidency to Trump, it suggests that fake news cost Clinton about 2.2 or 2.3 points apiece in Michigan, Pennsylvania and Wisconsin. And Clinton lost Michigan by just 0.2 points and Pennsylvania and Wisconsin by 0.72 and 0.76 points, respectively.
These are rough estimates, to be clear. But notably, Clinton's estimated drop-off in each state would be about three times bigger — or more — than the study's impact of fake news. That would mean that, for fake news not to have made the difference (according to these data), Michigan, Pennsylvania and Wisconsin would have had to be uniquely impervious to the effects of fake news, compared with the rest of the country.
The survey also notably doesn't measure what effect fake news might have had on increasing Trump's support, instead only focusing on how it depressed Clinton's. That could increase the shift. But even with this limited purview, it suggests it made a significant difference.
And it suggests it may well have cost Clinton the presidency.