When studying earnings inequality, social scientists typically treat individuals as single points of observations or a weighted average over their lifetime. Such "snapshot" measures of inequality are appropriate when individuals tend to follow similar earnings trajectories and when there are minimal fluctuations in earnings over the life cycle. However, recent research suggests that intragenerational mobility has been increasing in jobs, occupations, and earnings. As a result, the dispersion of earnings is likely to have changed over the life cycle, and this pattern may have shifted across different birth cohorts.
Sociologist Siwei Cheng adopts a cohort-centered approach to investigate the extent to which the life cycle structure of inequality has shifted across cohorts. This project aims to: 1) document cohort differences in the life cycle pattern of earnings inequality; 2) assess the extent to which individual-level trajectory heterogeneity, social group differentials, and earnings volatility contribute to the life cycle changes in inequality among different birth cohorts; and 3) examine how time-varying work and family experiences shape the life cycle earnings trajectories and how their effects vary across cohorts.