What does population density mean? Number of people per household square footage? Number of people per household? Number of people per zipcode? City/rural? Popu

What does population density mean? Number of people per household square footage? Number of people per household? Number of people per zipcode? City/rural? Population density is not a consistent predictor of covid19 spread by any of these measures, unless you also start taking other factors into account. Density matters "intuitively", but it's not borne out by the data.