A vast number of studies have examined the predictors of marriage and marital dissolution, and more recent studies have explored entry into and exit from cohabiting unions. At the same time, much attention has been paid to the rise in nonmarital childbearing and single motherhood. Yet, far less is known about a topic at the intersection of these two research literatures, namely the predictors of union formation, stability and change among couples that have children outside of marriage. Much of the research on union formation does not include unwed parents or explore the link between the timing of childbearing and relationship transitions. Most of the research on single mothers has focused exclusively on the mother-child dyad, with little recognition of the potential or actual role of the father in the lives of mothers or children. New research shows that more than four-fifths of unmarried couples are in a romantic relationship at the time they have a child, and just under half are living together (McLanahan et al., forthcoming). These findings suggest that many unmarried parents and their children are in "family- like" relationships, at least initially. Thus, researcher need to consider the factors associated with both stability and change in parents? relationships over time.
Beyond its importance for family demography and sociology, the topic of family stability and change among unwed parents is particularly timely from a policy perspective because the 1996 welfare reform placed limits on the receipt of public assistance for mothers on welfare, the vast majority of whom are unmarried. Some policy analysts have suggested that marriage may obviate the economic disadvantage among low- income women. In order to understand the possible role for marriage, it is critical to understand the characteristics associated with entry into marital versus nonmarital unions, as well as factors that influence the relationship trajectories of couples that have a child outside of marriage. In this paper, we use new data from the Fragile Families and Child Wellbeing Study to examine patterns of union formation among new unwed parents - first by looking at differences in parents? relationship status at birth, and then by looking at what happens to relationships one year following the birth. This paper provides an initial investigation into family formation among unmarried parents; as additional data from the Fragile Families Study become available, we will be able to explore this topic using longitudinal data on the full sample.