Experts say voluntary physical distancing in the United States was essential to slowing the spread of COVID-19 in the early days and weeks of the pandemic, even before such measures were mandatory. A group of researchers across four schools at Penn was interested in learning whether people's political beliefs influenced their decisions to stay home during that time.
"People were being asked to comply with things that were very costly to them," says political scientist Guy Grossman. "The question for us was, 'Why would they do that?'"
A new study co-authored by Grossman of the School of Arts & Sciences, Harsha Thirumurthy of the Perelman School of Medicine, Soojong Kim of the Annenberg School for Communication, and Jonah M. Rexer of the Wharton School found that political partisanship did in fact influence American citizens' decisions to voluntarily engage in physical distancing, particularly in response to communications by state governors.
Among the study's findings is that Republican governors who communicated the seriousness of COVID-19 in early March, a period during which the right-leaning media and President Trump were skeptical of the risk posted by virus, had a much stronger effect on behavior of people in Democratic-leaning counties within their states than on the behavior of people in Republican-leaning counties.
"This was the point in time when the national Republican consensus was to downplay the severity of the virus, so a Republican who's willing break ranks sends a very strong message that this is something that we need to get serious about, and in particular Democrats are very receptive to that kind of message," Grossman says.
The study also found the role local leaders play in shaping citizens' behavior is critical during these times.
"We're in an era in which everything is nationalized, with the outsized influence of Trump it can seem like local leaders don't matter. But this shows the role of local leaders, even amid a global pandemic, is also quite important," he says.
In the early days of the pandemic, Republican governors, on average, were slower to introduce prevention measures such as stay-at-home orders than were Democratic governors, and people who identified as Republicans were less likely to engage in physical distancing than those who identified as Democrats. But Republican governors in Massachusetts, Ohio, and Maryland took an early and aggressive approach to preventive measures. And the study found Democrats in those states were particularly responsive.
"We found that communication by the governor produces basically the same-sized effect in terms of social distancing behavior as the eventual lockdown policy itself," says Rexer. "It was surprising that these early voluntary behavior changes based on communication from local leaders were actually extremely important."
The study built on some publicly available data sets, but one of the innovative aspects was its look at the communication by governors on Twitter. Co-author Kim, a social media expert, downloaded the tweets of all governors' personal accounts and formal accounts between March 15 and April 1. A group of political science undergraduates and Wharton School students helped manually code the nearly 10,000 tweets, noting if they were COVID-related and whether they encouraged social distancing or sheltering in place, to capture the communication of governors.
Citizens' daily mobility during March 2020 was measured for the study using location information from a sample of mobile phones in 3,100 U.S. counties across 49 states.
"The study brings together a pretty wide array of data sources to look at this question," says Thirumurthy. "And all of the co-authors had expertise that was invaluable for carrying out the study: expertise in communications, people with expertise in empirical strategies to look at the effects of these lockdown recommendations and policies. It is a good demonstration of different disciplinary backgrounds and prior research experience being used to study an important topic."
The entire study took about three weeks of working long days and weekends, the co-authors say.
"This was easily the fastest any study has moved for me," Thirumurthy says.
They were motivated by a desire to get the results out quickly because the message has a timely relevance for how policymakers should think about communications regarding COVID-19 going forward, he says.
"There's still a very strong need for political leaders to send the right signals on these types of behaviors," he says.