Different data, different conclusions: How to grade social distancing efforts?
Gov. Roy Cooper assures North Carolinians that the likelihood of easing social distancing rules depends at least partly on how faithfully people follow them.
But different sets of data seem to point to different conclusions. That makes it hard to definitively evaluate how well the state’s 10.4 million people are doing their part to limit the spread of the coronavirus.
While the numbers appear to be encouraging in North Carolina in Google’s most recent report on mobility and a survey by Duke University points to continued increased awareness of social distancing, tech firm Unacast gave the state an overall grade of D-minus for its performance.
“These measures of movement are certainly useful to have in general,” said Brian Southwell, a researcher at RTI International and a professor at both Duke and the University of North Carolina who studies human behavior and infectious diseases.
“It’s helpful to know that there has been some sort of change,” he added. “But each of these measures is not necessarily a perfect indicator of how hard people are trying.”
Social distancing efforts have been in place for more than a month, and the statewide stay-at-home order expires at the end of April with Cooper saying another order is likely to follow without specifying what it might include. He says his team will gauge statistics including deaths, new infections and hospitalization rates.
“The better we can be at staying home through April,” he said, “the more likely we are able to ease restrictions.”
One issue with the raw numbers, Southwell said, is that they may not take into account proximity to essential businesses like grocery stores or pharmacies, or people’s behaviors when they are there.
“For example, if your grocery story is twice as far away as mine and you’re trying to get food for your family, whether you’re having that delivered or you’re going there, you’re going to generate twice the movement than I am,” he said. “It matters what different areas look like.
“It’s also the case that some of these general measures are not necessarily taking into account how people are acting – it’s not necessarily a measure of whether you’re wearing a mask, per se, and that matters, too,” he added. “So I think it’s possible for people to be moving around in the same sort of way and one person’s acting in a more irresponsible way than the other. That said, of course, it’s somewhat heartening to see that there has at least been some improvement. There is a lot of room for improvement, and that’s something to keep in mind, too.”
Google’s most recent figures seem to indicate a positive trend, with the tech giant comparing people’s location tendencies against baseline data collected in January and early February. The aggregate, anonymized data was created from users who manually turned on the location settings in their cellphones.
It shows drops of 43 percent from the baseline in North Carolina at retail and recreation locations, 14 percent at grocery stores and pharmacies, 55 percent at transit stations and 38 percent at workplaces. It also shows increases of 11 percent at residences and 5 percent at parks.
Conversely, Unacast graded North Carolinians a bit more harshly for their social distancing efforts.
In its most recent update Monday, the tech firm that also tracks location data docked state residents for only reducing their travel on average by between 25 and 40 percent – an A grade corresponds to a reduction of better than 70 percent. It also awarded the state an F for not reducing non-essential visits by more than 55 percent.
Seven counties in the CBS 17 viewing area – Johnston, Lee, Harnett, Cumberland, Wayne, Wilson and Nash counties — received Fs. The best grades in the area went to Orange and Warren counties, which each received a C. Wake County earned a D-plus while Durham County had a C-minus.
And Duke is conducting a weekly voluntary survey to measure people’s attitudes and behaviors about the coronavirus crisis, with the most recent findings indicating that 97 percent of respondents say they are taking it seriously and a growing percentage of people are having fewer face-to-face interactions with people outside their household.
“Some of these measures, they’re useful to have as part of our tool kit,” Southwell said. “It’s useful to know that, relative to February or January, that there has been a change. Some of these measures are better than others, in terms of taking a look at what types of places people are going to, as well.”