Life Course Trajectories of Inter-Spouse Income Inequality

Kimberlee A. Shauman, University of California, Davis

This paper presents an analysis of the dynamics of inter-spouse income inequality. The analysis has three aims: (1) to describe the life course pattern of spousal income inequality, (2) to test if there are distinct developmental trajectories of inter-spousal income inequality that may reflect distinctive types of marriages, and (3) to describe the character and prevalence of the distinct patterns. I use finite mixture models to analyze 20-year longitudinal sequences of earnings inequality in married couples using data from the PSID. Preliminary results indicate that U.S. couples experience six distinct patterns of inter-spousal income inequality. Trajectories describing significant income disparities favoring husbands are the most prevalent pattern of income inequality, and this "traditional" arrangement is found to follow four developmental pathways distinguished by the magnitude of the income gap and the timing of its growth. Income disparities favoring wives are sufficiently prevalent to support the identification of two distinct trajectories.