Intergenerational mobility, measuring the ability to achieve economic success regardless of family background, is a critical reflection of a society’s commitment to equality of opportunity. Rising income inequality has raised concerns about the potential erosion of upward mobility. While education has traditionally been viewed as the path to mobility, its transformative power is facing challenges in a rapidly evolving job market. This project reorients the focus of intergenerational mobility research by highlighting the labor market as an arena for the reproduction of advantage. It employs a comparative approach, using administrative data from four countries: Sweden, Austria, England, and the United States. It also incorporates evidence from a broader set of nations through cross-national surveys, longitudinal household surveys, labor force surveys, secondary data, and digital trace data. The project employs cutting-edge empirical methods, including quasi-experimental designs, event studies, within-family comparisons, decomposition analyses, counterfactual simulations, and diagnostic checks to rigorously assess the extent of inequalities in the labor market. The research investigates how family background influences the sorting of individuals to employers and workplaces, accounting for education and occupation, and explores variations in career progression within and between employers. It comprehensively catalogues and assesses mechanisms shaping workplace inequality, contributing to the development of social closure theory. Additionally, the project evaluates intervention strategies, encompassing both employer practices and government actions, to promote fair opportunity in the labor market.