Shlomo Angel wearing a blue medical mask


Using Metropolitan Area Data to Predict the Virus’s Next Move

By Barbara Stepko (CAS ’82)

By now, those color-coded maps, charting the growth of the pandemic, have become a familiar sight on our phone and TV screens. But how relevant are they? It’s a question that a research team at the Marron Institute of Urban Management has been tackling since March. That team is led by Shlomo “Solly” Angel, professor of city planning at Marron.

Although data on confirmed cases and deaths in the US are reported daily for counties and states, Angel demonstrates in his paper “Do US Counties Infect Each Other?” that you can explain and predict the variation in the geographic spread of COVID-19 by studying metropolitan statistical areas (MSAs)—particularly in counties, by studying adjacent counties and MSAs.

Another reason why Angel believes MSAs should be the focus of tracking and taming the novel coronavirus: they contain 86 percent of the US population, along with 90 percent of the cases and 93 percent of the deaths. And because populations, income levels, healthcare facilities, and other elements are comparable, it’s easier to look for patterns.

Using his data, Angel and his team set out to find why some cities have higher numbers than others. The conclusions: the cases and deaths in an MSA are results of its population size (the greater the population, the more cases and deaths per capita), its geographic size, and timing (one reason some MSAs have reported more infections and deaths is because their outbreaks occurred earlier).

Surprisingly, density (the number of people per square mile) is not a primary cause of the spread. In fact, denser cities, says Angel, are somehow better able to contain their numbers and have far fewer COVID cases than more sprawling ones.      

“We should not compromise the long-term density of our cities by the short-term need for social distancing,” says Angel, who notes that flight to the suburbs has repercussions related to global warming. Simply put, “we need urban densities to increase, not decline,” says the professor. “The pandemic may show us the importance of metropolitan coordination: it can save lives.”