5 Slide Series

5 Slide Series

COVID-19 Case Growth Dynamics by Population Density
Publication Date: May 29, 2020

This edition of the 5-slide series has multiple components. We have grouped all counties (and states) into cohorts based on their overall population per square mile, to quantify the relationship between population density and COVID cases per capita. As one would expect, COVID has spread much more rapidly in higher-density population areas, with the per capita rate of infection through May 27 more than 3 times higher in our most dense population cohort (counties with more than 1,000 residents per square mile) than in our most sparsely populated cohort counties with fewer than 50 residents per square mile). Interestingly and perhaps importantly, the recent rate of new case growth is highest across the most sparsely populated counties – the number of new cases this past week was 10% lower than in the previous week across the nation’s most densely populated counties, but 6% higher across the most sparsely populated counties.

We have also grouped counties by the degree to which their volume of new cases has increased or declined this week versus the prior week. 

At the state level, we show each state’s progression of new confirmed cases each week throughout May. While the volume of new cases this past week (148,000) was 7.5% lower nationwide than during the previous week, the volume of new cases remains very high and has been fairly consistent. May’s highest weekly new case total was 165,000. Many states have experienced an increase in new cases.