This slide demonstrates the between-country comparability (median household income in census tracts) across five socioeconomic strata that typically resulted from construction of an ecological SES variable with the previously described method.

It also tends to validate the notion that the prevalence of poor people is very high in the lowest income strata (two-thirds are poor or near poor [200% of federal criterion]) and that their risk of being under- or uninsured is much greater [10- to 15-fold prevalence ratios] than among those who live in the highest income strata.