Robust and fragile determinants of the infection and case fatality rates of Covid-19: international cross-sectional evidence

An attempt is made to identify the factors that can explain inter-country differences in the severity of Covid-19, measured by the infection and case fatality rates. To circumvent the problem of the sensitivity of the results with respect to the selected set of explanatory variables, extreme bounds analysis (EBA) is applied to a cross-sectional sample of 154 countries. The results show that the infection and fatality rates depend on different factors, except for the number of tests, which is a robust determinant of both. An interesting result is that the infection rate depends on urban population rather than the overall population density. Another interesting result is that the fatality rate depends on the age structure of the population and population density but not on the percentage of urban population.