Cohabitation Is No Longer Associated With Elevated Spousal Homicide Rates in the United States

Margo Wilson and collaborators discovered that cohabiting couples had very much higher spousal homicide rates than those in registered marriages, and cross-national research has shown this difference to be widespread. We now find that homicide rates in the two sorts of unions have converged in the United States, such that the previously large difference had completely vanished by 2005. Distinct age patterns whereby registered marriages are most lethal in youth and cohabitation is most lethal in middle age have nevertheless persisted. While their homicide rates were converging between 1990 and 2005, married and cohabiting couples were not growing more similar in their basic demographic attributes: age distributions and unemployment rates remained distinct, and differences in education and income actually increased. Why homicide rates in the two classes of unions have ceased to differ remains unknown. We suggest some lines of research that may help provide answers.