Abstract
This chapter argues that a methodology based on the interactionist concept of career offers an innovative research design for understanding the (un)making of women's underrepresentation in union leadership positions. Drawing on a comparative research project that investigated four unions in France and the UK, it presents and illustrates this methodology. It investigates how different institutional, organizational and individual processes shape union careers and contribute to the reproduction of inequality regimes within trade unions, while unveiling the conditions, including individual agency and equality policies, that have enabled progress to be made in some unions.