By Navin Vembar
Despite the fact that we’re seeing COVID-19 cases and deaths rise and most of the country under increasing risk, people still traveled more than they had in the prior weeks, in some cases by quite a lot. Though, generally, when they went to an out-of-state location, they moved similarly to how they are moving now – generally keeping still.
The first thing to note is how many people stayed away from their home on a given day. To establish a baseline of home counties for each device, we use the mobility data from cell phones from the second week of November and determine where those devices stay at night. We then compare those baselines to the nightly home locations on each day up to 11/25. This is similar to what we’ve done when analyzing displacement after hurricanes. Throughout this piece, we were focused on when people stayed out of state, using that as a proxy for long-distance visitation and movement. Though imperfect, it paints a picture of people leaving home to visit others.
First off, let’s look nationally at how many people are staying out of state by day – and we see an obvious significant jump between the 18th and Thanksgiving Day. But, interestingly, when we compare where people were staying, if they were staying out of state, they concentrated in a few states.
The above map compares the number of out-of-state visitors to a state on the 18th and the 23rd. Clearly, a lot of people came to visit Florida over Thanksgiving than traveled there the week prior. Zooming into the county level, we can get some clarity on where people are going – in fact, though people visited everywhere in the state, we can see a clear concentration in one county.
Stepping back, if we look at the entire country at the county level, we see that, for the most part, there’s not a lot of concentration of out-of-state travel to specific counties except in isolated cases – Orlando, Las Vegas, Chicago and Phoenix, for example. The out-of-state travelers are spread across country, increasing overall out-of-state visitors in a large number of counties in the US.
Which, given the state of COVID-19’s spread throughout the country, it should worry us when it comes to what’s going to happen to cases in the next two weeks. As people travel home, especially from places with high incidences of COVID-19, we could see surges in cases as people bring the disease home or it spreads from even smaller gatherings.