Demons of density do higher-density environments put people at greater risk of contagious disease?

We study the relationship between density and COVID during three distinct waves of the pandemic in New York City. Unlike prior work, our analysis uses individual Medicaid claims records, which include a rich array of demographic characteristics and pre-existing medical conditions and cover a near universe of low-income New Yorkers. In brief, our results suggest that living in higher density neighborhoods did not heighten the risk of COVID hospitalization. The size of a multifamily building made little difference either, and people living in public housing developments, which are typically highly dense environments, were less likely to be hospitalized for COVID. However, while neighborhood and building density do not seem to matter, we find significant, positive relationships between COVID hospitalization rates and household size. Specifically, we see that people living in large households or in neighborhoods with high levels of crowding were more likely to be hospitalized for COVID. In other words, our results suggest that crowded living quarters – which can occur at any level of population density – and not density itself, increase the risk of COVID hospitalization. We also see a strong correlation between being unstably housed or living in institutional settings and COVID hospitalizations.