This paper argues that fertility transition comes about when personal material well-being is determined less by personal relationships than by formal education and skill training. This transformation occurs when changes in opportunity structure and the labor market increasingly reward educationally acquired skills and perspectives, for these changes have the effect of sharply limiting or eliminating the expected intergenerational income flows from or through children. This modification and extension of Caldwell's wealth flows model permits us to account for historical-, regional-, and social-class-specific differences in the onset and pace of fertility transition, and points to new, macro-level socioeconomic indicators whose ability to account for historical variation infertility is validated by a preliminary test.