NC vs. SC: What GPS phone data say about how well residents stay home for coronavirus

How do North Carolina and South Carolina compare when it comes to staying home during the coronavirus pandemic?

A data company is using GPS data from millions of mobile devices to analyze human movement in the U.S. since the beginning of February.

SafeGraph, which has companies such as Verizon and Sysco for clients, compiles GPS data to track how people in the U.S. are responding to the pandemic. It’s offering the information to researchers, nonprofit organizations and government officials.

The states have similar scores in the analysis even though North Carolina issued a stay-at-home order before its neighbor. The stay-at-home order in South Carolina went into effect Tuesday, and the most recent data is from several days before this. Cities and counties have separate orders that vary compared to statewide rules.

Nevertheless, they both lag much of the country in staying home, and South Carolina is closer to the bottom, according to the data over the weekend.

North Carolina stay-at-home data

• Stay-at-home index: 13.32%

This figure represents the percentage of people staying home above a baseline on Saturday, the most recent day available. The baseline was recorded in the first week of February.

It means about 13% more North Carolina residents are staying at home all day compared to early February — when schools and businesses across the state remained open.

The state ranked 37th in the U.S. by this metric.

Overall, about 37% percent of North Carolina residents stayed home, the data show.

South Carolina stay-at-home data

• Stay-at-home index: 10.96

South Carolina trails North Carolina by just over 2% in the number of people who stayed home Saturday.

It’s important to note that these figures vary by date, though Kansas and Missouri continue to score similarly. In fact, South Carolina scored nearly identical to North Carolina the previous Saturday. That was two days before the North Carolina order went into effect.

Only Arkansas and Wyoming trailed South Carolina by this metric.

Overall, about 33.4% of South Carolina stayed home on April 4, data shows.

U.S. social distancing data

Across the country, more people are staying home each day, according to the data.

The nationwide stay-at-home metric was 18.52% on Saturday, a sign more Americans are listening to social distancing guidelines.

That’s a jump from approximately negative 3% on March 9, meaning about 3% more people were out of the house compared to the baseline week in early February.

On that day, the U.S. had 560 confirmed cases and neither the World Health Organization or the CDC had officially declared a pandemic, according to CNN. Now the country has more than 450,000 confirmed cases and more than 16,000 deaths, according to Johns Hopkins University.

New Jersey and New York lead the country in the analysis’ shelter-in-place index at 29.52% and 24.86%, respectively.

Stay-at-home methodology

SafeGraph is providing the stay-at-home information dashboard because it’s a primary way governments are combating the coronavirus pandemic. The company says its index is different than other social distancing data sets because it’s not based on total distance traveled.

“Whether to visit a neighbor or to visit the grocery store, whether the distance traveled is 10 miles or 0.1 miles, all ‘away-from-home’ events are classified the same in this dashboard,” according to the company. “We think this is a useful metric because one does not need to travel long distances to undermine social-distancing and enable viral transmission.”

The data is generated by GPS pings from 45 million anonymous smartphones, according to the company. An “event” is classified as each time the device leaves its home. A “home” is defined as the nighttime location over a six-week period.

The company says it doesn’t know or want to know the the precise home address of the devices.

This story was originally published April 9, 2020 at 7:48 PM.