Does Education Delay the Timing of First Birth?

Fertility has been declining almost continuously in both developing and developed economies over the past thirty years. A component of that change has been not only a reduction in the number of children a given woman bears but also the timing of her first birth. The average age of first birth in the United States has increased from 21.4 in 1970 to 25.1 in 2002 (Centers for Disease Control 2004). It is often asserted that these trends are largely explained by the rising education levels of women. However, it remains an open question whether the acquisition of education causes women to alter their fertility decisions, whether the timing of motherhood affects the education attainment, or whether the acquisition of education is a simultaneous outcome determined by some other factor that accompanies the change in fertility. This paper will attempt to isolate these effects. We use human capital theory to frame an empirical investigation into this question. In that framework educational investment is taken with an eye to the marginal rate of return on each additional year of education (measured by the difference between the net discounted present value of additional earnings and additional costs associated with each year of education). To us