Jane Waldfogel, Terry-Ann Craigie, and Jeanne Brooks-Gunn review recent studies that use data from the Fragile Families and Child Wellbeing Study (FFCWS) to examine why children who grow up in single-mother and cohabiting families fare worse than children born into married-couple households. They also present findings from their own new research.

Analysts have investigated five key pathways through which family structure might influence child well-being: parental resources, parental mental health, parental relationship quality, parenting quality, and father involvement. It is also important to consider the role of the selection of different types of men and women into different family types, as well as family stability. But analysts remain uncertain how each of these elements shapes children's outcomes.

In addition to providing an overview of findings from other studies using FFCWS, Waldfogel, Craigie, and Brooks-Gunn report their own estimates of the effect of a consistently defined set of family structure and stability categories on cognitive, behavioral, and health outcomes of children in the FFCWS study at age five. The authors find that the links between fragile families and child outcomes are not uniform. Family instability, for example, seems to matter more than family structure for cognitive and health outcomes, whereas growing up with a single mother (whether that family structure is stable or unstable over time) seems to matter more than instability for behavior problems. Overall, their results are consistent with other research findings that children raised by stable single or cohabiting parents are at less risk than those raised by unstable single or cohabiting parents.

The authors conclude by pointing to three types of policy reforms that could improve outcomes for children. The first is to reduce the share of children growing up in fragile families (for example, through reducing the rate of unwed births or promoting family stability among unwed parents). The second is to address the pathways that place such children at risk (for example, through boosting resources in single-parent homes or fostering father involvement in fragile families). The third is to address directly the risks these children face (for example, through high-quality early childhood education or home-visiting policies).