Using Trump’s Vaccine Endorsement Boosts COVID-19 Shots

A video compiled from Fox News clips of former President Trump and his family urging his supporters to get vaccinated against COVID-19 proved to be a cheap and effective way to convince some vaccine skeptics to get their shots.

In a large-scale ad experiment published today, a team of researchers from UC Berkeley’s Haas School of Business, Stanford University, University of North Carolina at Chapel Hill, and North Carolina State University compiled a public service announcement from existing footage and aired it on YouTube channels—including Fox News’ channel—in more than 1,000 U.S. counties with low vaccination rates. Compared with similar counties where the ad wasn’t shown, those counties recorded 104,036 additional vaccinations, at a cost of less than $1 per new shot.

The randomized controlled trial proved the researchers’ hunch that a partisan message would be a potent way to overcome the entrenched partisan divide around COVID-19 vaccines, according to co-author Steven Tadelis, professor of business and public policy at the Haas School of Business. It was also relatively inexpensive.

“Creating an intervention that effectively costs about $1 per extra vaccine is remarkably cost-effective, and a small fraction of the cost of other interventions,” Tadelis said, noting that studies of U.S. state vaccine lotteries put the cost at $68 to $82 per vaccine. Offering people direct compensation for getting vaccinated in Sweden put that cost at $24.

“Creating an intervention that effectively costs about $1 per extra vaccine is remarkably cost-effective, and a small fraction of the cost of other interventions.” —Steven Tadelis, Berkeley Haas

Using politics to overcome the political divide

Data from the Kaiser Family Foundation found that among the 27% of American who remained unvaccinated as of October, 60% identify as Republicans and just 17% as Democrats. Counties that voted heavily for Trump experienced COVID-related death rates nearly three times higher than counties that voted heavily for Joe Biden, an NPR analysis found.

Although Trump spearheaded Operation Warp Speed and he and former First Lady Melania Trump got their shots as soon as the vaccine was available, Trump did little to encourage vaccine uptake. Meanwhile, messaging from the Centers for Disease Control and Prevention (CDC) and medical experts about the vaccine’s efficacy has been overshadowed by a drumbeat of skeptical Fox News personalities who are also among Trump’s biggest boosters.

“We felt like there should be a better way to send a message that would resonate with people on the right,” said Stanford economics professor Brad Larsen, lead author of the study, in a press release.

“We felt like there should be a better way to send a message that would resonate with people on the right.” —Brad Larsen, Stanford University

The National Bureau of Economic Research working paper was co-authored by political science professors Timothy Ryan, Marc Hetherington, and Rahsaan Maxwell from the University of North Carolina at Chapel Hill and Steven Greene from North Carolina State University.

Creating the experiment

The researchers received funding for the experiment from the Vaccine Confidence Fund, and it was approved under the Institutional Review Board at Stanford University.

They hired a professional video editor to create a 27-second public service announcement with an upbeat soundtrack. It opens with the Fox 13 News Utah anchor declaring, “Donald Trump is urging all Americans to get the COVID-19 vaccine.” It then cuts to a phone interview in which Fox News anchor Maria Bartiromo nods in agreement while then-President Trump says, “I would recommend it, and I would recommend it to a lot of people that don’t want to get it, and a lot of those people voted for me, frankly.”

Next is another clip of the Fox 13 News Utah anchor explaining, “Both Trump and former First Lady Melania Trump did receive their vaccines privately in January at the White House.” The final shot shows a social media post Ivanka Trump shared when she got her jab. The ad closes with the statement, “Your vaccine is waiting for you.” It also includes a link back to the original broadcast.