Interventions to promote healthy marriages and strengthen families with unmarried parents are most likely to succeed if they are based on a sound understanding of the determinants of union formation, stability, and quality. With this in mind, the Administration for Children and Families contracted with Abt Associates for a review of the quantitative research on this subject. The review was to focus on the influences most relevant to policy. Its objective was to point to important gaps in knowledge and data and analyses needed to fill them. Evidence on disadvantaged families was to receive special emphasis given the compelling societal interest in decreasing the number of poor children growing up in single-parent families. The project also was to provide a companion guide to major national surveys offering opportunities to address key unanswered questions.
The vast size of the literature on marriage and cohabitation determinants and finite project resources prohibited an exhaustive review of the evidence. Rather, we have attempted to sift through key empirical studies and seminal reviews to identify important insights and gaps in the current knowledge base. Our review identified ten broad categories of influences that are especially important. In this summary, we first discuss main research findings and gaps for each influence and then offer observations on cross-cutting research needs.