The Effect of First Interbirth Interval and Union Status on Women’s Poverty at Midlife

Amanda Stevenson, University of Texas at Austin

The relationship between childbearing and socioeconomic status is complicated by multiple sources of endogeneity. Cross sectional and logintudinal designs cannot account for selection into childbearing patterns and thus cannot assess causal relationships between fertility and later life outcomes. Focusing on the timing of childbearing and union status through early and mid-adulthood, I use miscarriage to construct an instrument for delivery and build a counterfactual condition for having a short temporal space between births. Using this approach with data from the National Longitudinal Survey of Youth 1979, I estimate the effect on midlife poverty of having first and second births within 24 months of each other. My results indicate that these short interbirth intervals are causally related to increased midlife poverty. Extension of the work to illustrate the role of union status (continuous marriage since first birth versus all other union status histories) and midlife health as pathways is underway.