Before revision: We consider variations in the rate of spread of COVID-19 , firstly comparing between European countries and secondly comparing between US states. We show that the population density has a small but significant effect on the rate of spread of the virus. However we show that measures of ` lived population density', which capture density as perceived by a randomly chosen person, do a better job of explaining variations in the rate of spread , achieving R^2 = 0.45 in Europe.
After revision: We consider variations in the rate of spread of COVID-19 pandemic has progressed with varying degrees of intensity in individual countries, suggesting it is important to analyse factors that vary between them. We study measures of ` lived population density', which capture density as perceived by a randomly chosen person, do a better job of explaining variations in the rate of spread , achieving R^2 = 0.45 in Europe.