Determinants of Long-Term Unions: Who Survives the “Seven Year Itch”?

Most studies of union formation focus on short-term probabilities of marrying, cohabiting, or divorcing in the next year. In this study, we take a long-term perspective by considering probabilities of forming unions by certain ages and maintaining them for at least 8, 12, or even 24 years. We use data for female respondents in the 1979 National Longitudinal Survey of Youth to estimate choice models for multiple stages of the union-forming process. We then use the estimated parameters to simulate each woman’s sequence of union transitions from ages 18-46, and use the simulated outcomes to predict probabilities that women with given characteristics follow a variety of long-term paths. We draw three broad conclusions. First, a representative woman has the same 28% chance of cohabiting or marrying and maintaining the union for 12+ years regardless of whether it is a first union formed by age 22, a first union formed by age 28, or a second union formed by age 34. Second, unions formed via cohabitation contribute significantly to the likelihood of experiencing a long-term union, and this contribution grows over the lifecycle. This finding reflects the fact that the high probability of entering a cohabiting union more than offsets the relatively low probability of maintaining it for the longterm. Third, the likelihood of forming a union and maintaining it for the long-term is highly sensitive to race, but is virtually invariant to factors that can be manipulated by public policy such as divorce laws, welfare benefits, and income tax laws.