Abstract:
The authors employ a newly developed method to disentangle age, period and
cohort effects on nonmarital fertility ratios (NFR) from 1972 to 2002 for U.S. women
aged 20-44 – with a focus on three specific cohort factors: family structure, school
enrollment, and the ratio of men to women. All play significant roles in determining NFR
and vary substantially for whites and blacks. Indeed, if black women and white women
had cohort characteristics typical of the other group, age-specific NFRs for black women
would decline markedly, while those for whites would increase markedly. Hence, cohort
related variables contribute substantially to black-white differences in NFR in adulthood.
Early family structure and education are particularly crucial in the racial differences.
Most distinctively, while the impact of school enrollment on NFR is significantly
negative for whites, the impact is significantly positive for blacks, perhaps due to the
dominance of the “independence” effect.