Staying Power: Unpacking Seniority as a Gendered Informal Institution in Parliament

Abstract Political seniority—commonly understood as accumulated parliamentary tenure—is an underexamined informal institution that structures access to power. This article adopts a critical realist approach grounded in feminist institutionalism to theorize seniority not as a neutral reflection of experience, but as a gendered institution with uneven effects. Drawing on qualitative interviews with members of the French National Assembly, we develop an analytical model identifying three interconnected forms of power embedded in seniority: knowledge, legitimacy, and influence. These elements operate in a causal chain, in which knowledge fosters legitimacy, which in turn enables influence. We show that while seniority can benefit all parliamentarians and serve as a powerful resource, it does not confer power equally. Women face structural barriers to accessing seniority, and even when attained, legitimacy is not guaranteed, and thus influence is difficult to exercise. Our model offers a new lens on how informal institutions reproduce gendered hierarchies in parliamentary politics.