The indirect costs of the epidemic vary with certain characteristics of those affected. In practice, most estimates adjust only for the age and sex of PWAs but do not account for their education, training, and labor market experience. The labor market qualifications of PWAs vary among affected areas. Some epidemiological evidence suggests that in African countries, those with more education have higher rates of HIV prevalence than do the less well educated. In these countries, the indirect costs of AIDS will be disproportionately high. In developing countries, however, HIV infection is increasingly found among less-educated segments of the population.