Nonmarital childbearing has increased dramatically during the past several decades, with the fraction of births occurring outside of marriage rising six-fold in the latter half of the 20^thcentury. Although many unmarried parents are cohabiting when their child is born, about two-thirds will be living apart by the time their child turns five. Since children typically live with mothers following parental separation, the modal child born outside of marriage will live apart from their father over a large number of years. As a result, the extent to which nonresident fathers are able to cooperate effectively with mothers in rearing their common child—referred to as ‘coparenting’—may have important implications for children’s wellbeing and development.

The present study examines whether nonresident fathers’ coparenting matters for children’s behavior among couples who break-up following a nonmarital birth. While research has shown that positive coparenting is beneficial for children after divorce, the circumstances surrounding the dissolution of a cohabiting or dating relationship—and the implications for children—may be quite different. We examine the extent to which positive coparenting is associated with lower levels of externalizing and internalizing behavior problems among children aged three through nine, and we evaluate two possible mechanisms for this association: father-child engagement and child support payments. Prior studies have demonstrated that a low-quality coparental relationship reduces nonresident fathers’ provision of time and money to their child. Given the importance of these parental investments, it is likely that fathers’ inability to coparent effectively may negatively impact children through these two pathways.

Our data come from the Fragile Families and Child Wellbeing Study, a survey of 4,897 births that occurred between 1998 and 2000 in 20 large U.S. cities. Follow-up interviews were conducted when children were one, three, five, and nine years old. Our sample consists of approximately 2,200 couples who were unmarried when the child was born and ended their relationship within the nine years following their child’s birth. To conduct our analyses, we will use random- and fixed-effects models to investigate the associations between nonresident fathers’ coparenting behavior and children’s externalizing and internalizing behavior problems. Both of these techniques take advantage of the dataset’s longitudinal design by using repeated observations pooled over time to control for observed and unobserved characteristics of mothers, fathers, and children. We will also add time-varying measures of father-child engagement and child support payments to our models in order to assess whether these factors mediate the associations between coparenting and children’s behavior problems.

Preliminary results indicate that nonresident fathers’ coparenting is a key predictor of children’s externalizing behavior problems, and to a lesser extent, their internalizing behavior problems. Our next step is to examine whether engagement or child support payments help to account for these associations. Given that the vast majority of unmarried parents will break up within a few years of their child’s birth, these results point to the importance of designing new policies and programs to help nonresident fathers navigate the challenges of working with mothers to raise their common child.