Effects of family instability, income, and income instability on the risk of a premarital birth

In previous work, my colleagues and I reported (1) a strong and statistically significant association between frequent changes in the numbers and types of parental figures a young woman has lived with and her risk of bearing her first child out of wedlock, and (2) weak and statistically nonsignificant associations between measures of a young woman's exposure to a mother-only family during childhood and adolescence and her risk of a premarital birth (Wu and Martinson 1993). A serious limitation of these findings is the absence of controls for income. Failure to control for income is especially problematic because the positive association between frequent changes in family structure and premarital birth risks could be an artifact of changes in economic circumstances that typically accompany family changes. In this study, I use prospective income histories and retrospective parental histories from the National Longitudinal Survey of Youth so determine if the effect of family instability on premarital births is an artifact of low, unstable, or declining family income. I find that low income, declining income, and frequent changes in family structure are associated with significantly increased premarital birth risks. The effects of income and change in family structure are largely independent.