Intergenerational Transmission of Age at First Birth in the United States: Evidence from Multiple Surveys

It is well established that the timing of childbearing is transmitted from parents to children in the United States. However, little is known about how the intergenerational link has changed over time and under structural and ideological transformations associated with fertility behaviors. This study first considers changes across two birth cohorts from the National Longitudinal Study of Youth (NLSY) in the extent to which parents’ age at first birth is transmitted to their children. The first cohort includes individuals born during the late 1950s through the early 1960s (NLSY79) while the second includes individuals born in the early 1980s (NLSY97). Results from discrete-time event history analyses indicate that the intergenerational transmission of age at first birth between mothers and daughters as well as between mothers and sons significantly increased over the period. These results were confirmed by analyses of data from three cycles of the National Survey of Family Growth (NSFG) spanning the same time period. Over this period, age at first childbirth became increasingly younger for children born to teenage mothers and increasingly older for those born to mothers who entered parenthood after age 25. These patterns have important implications for reproductive polarization and the low-fertility trap hypothesis.