What’s love got to do with it? Homogamy and dyadic approaches to understanding marital instability

What determines marital instability is an important area of research for demography, sociology and economics, with a host of public policy implications. This paper improves our understanding of the issue through the use of rich longitudinal data and the application of advanced research approaches for one of the first times anywhere, and certainly uniquely for Australian data. The combination of method and recent Australian data represents a significant advance in this research area. Using data from waves 1–7 of Household, Income and Labour Dynamics in Australia Survey, 2,482 married couples—where both partners are respondents in the first wave—are traced over 6 years to identify factors associated with marital separation. The data are analysed dyadically; that is, the characteristics of both partners in each couple are considered in tandem. This allows assessment of whether marriages between partners with similar characteristics (homogamy) are more likely to last than are marriages between dissimilar partners, or whether particular characteristics of wives or husbands—independent of their partners’—are more strongly associated with marital stability. A Cox proportional hazards model with time-varying covariates is used to assess the association of characteristics with marital separation. Our most important contribution relates to the role of homogamy in marital stability or instability and in the context of spousal differences we find the following factors associated with higher risk of marital separation: age, education, preference for a child, and drinking and smoking behaviour. As well, there is a clear positive association between separation and: dissatisfaction with the relationship; husband’s unemployment and perceived financial stress; early age at marriage; separation of parents; second-plus marriage; resident children born before marriage; and low household income. The last of these findings should matter directly for public policy formulation.