A Life Course Approach to Income Inequality: Age-Graded Wage Returns of STEM Majors

Qu, Yue

While scholars have long investigated the heterogeneous returns to college, they often overlook how the various returns, particularly those shaped by horizontal school tracking (such as academic disciplines), change with age. The present study aims to address this gap and explore how the wage gap between STEM and non-STEM majors evolves over the life course, including corresponding gender differences. Data from the American Community Survey (ACS) and the National Longitudinal Study of Youth 1979 (NLSY79) will be analyzed using age-period-cohort (APC) models and Growth Curve models. Additionally, Oaxaca-Blinder (OB) decomposition will be employed to unveil underlying mechanisms.

The objective of this study is to investigate three interconnected research questions. First, it aims to analyze how the wage gap between STEM and non-STEM majors evolves throughout individuals' careers, shedding light on the dynamics of wage disparities. Then, it seeks to examine gender differences in the age-graded wage returns to STEM majors, incorporating a heterogeneity analysis. Lastly, it aims to identify the mechanism and decompose the factors, particularly encompassing endowment effects (occupation, industry, and major-job matching) and coefficient effects (such as personal values, discrimination, and bias) that explain the wage gap between STEM and non-STEM majors over the life course and the corresponding gender differences.