Marriage duration and divorce: the seven-year itch or a life-long itch?

Hill Kulu, University of Liverpool

Most studies show that the risk of divorce is low during the first months of a marriage; it then increases to reach a maximum and thereafter begins to decline. The reason for this rising-falling pattern of divorce risk, however, is far from clear. Classical psychological literature considers this pattern consistent with the notion of a seven-year itch. Other researchers argue that the rising-falling pattern of divorce risk is a consequence of misspecification of longitudinal models because of omitted covariates or unobserved heterogeneity. This study investigates the causes of the rising-falling pattern of divorce risk. We use register data from Finland and apply multilevel hazard models. We first study the hazard of divorce over the marriage duration with and without controlling for a set of demographic and socioeconomic characteristics of women and their partners. We then control for unobserved heterogeneity to detect any changes in the shape of baseline risk. We also examine the hazard of divorce over the marriage duration separately for both first and subsequent marriages as well as across cohorts to identify any changes over years.