Population and education are likely to play a central role in public policy in South Africa as it emerges from apartheid. Household survey data are used to examine mechanisms that underlie the negative association between fertility and education. First, education is not randomly assigned within a population. It is demonstrated that part of the association between education and fertility reflects self-selection in educational achievement. Second, because education and household resources tend to be correlated, a woman's education may be a proxy for her income. Female education continues to have a powerful negative association with fertility. A third set of experiments attempts to isolate the relationship between skills learned in school and demographic outcomes. Performance on quantitative and comprehension tests has an independent impact on fertility. The impact of comprehension skills is particularly large, suggesting that assimilation of information may be important in affecting family decisionmaking.