Results
Table 2 reports the regression results for relative incidence (reported cases over total population) obtained by OLS, Tobit without controlling for other vaccines and Tobit controlling for other vaccines. For both OLS and Tobit, the estimated coefficients represent the marginal effect of the covariates on the outcome variable. Table 2 shows large and strongly significant effects for per capita gross domestic product and Human Freedom Index (positive) and for the summer season and BCG vaccination (negative), even controlling for more vaccinations.
Table 3 contains estimated coefficients, with corresponding standard errors and marginal effects, for CFR and MRs fractional regressions. This table reveals large and strongly significant effects for health expenditure and tropical position (positive) and for summer season and, above all, BCG vaccination (negative), even controlling for more vaccinations.
Table 4 contains the results of a robustness analysis on relative incidence, where alternative measures for BCG have been used as explanatory variables instead of the BCG dummy.
Table 5 contains the results of the same robustness analysis performed on the CFRs and MRs. Both tables 4 and 5 confirm the results obtained with the previous regressions.
All regressions feature the same set of explanatory variables, listed in the data section, but tables only report statistically significant coefficients, as well as their respective significance (10%, 5%, or 1%).