What drives the selection of young candidates? Evidence from Germany’s mixed-member proportional systems

Young adults are descriptively underrepresented in parliaments worldwide — a fact that has attracted increasing scholarly and institutional attention in recent years. While most research has focused on institutional and contextual factors that explain cross-national variation in descriptive youth representation, less attention has been paid to the role of political parties as “gatekeepers” to elected office. This gap persists despite a growing body of literature on supply-side explanations and voter evaluations of candidate age. In this paper, we study candidate selection as an indicator of parties’ descriptive inclusiveness and a crucial stage for shaping legislative composition. We focus on the case of Germany, a particularly valuable context given its mixed-member proportional electoral system, strong party-centered candidate selection processes, and notable variation in parliamentary youth representation across parties and regions. Drawing on a novel dataset of over 50,000 candidacies for all elections at the federal level and the state level since 2013, our core question runs: What drives the nomination of young candidates (conceptualized as being under 31 years old)? More specifically, we analyze whether the share of young nominees is related to factors on the individual/candidate level, the party level and the institutional level. We first assess the share of young candidates across party lists, followed by a weighted measure that accounts for their actual chances of entering parliament. Our analyses show that while the overall share of young candidates has increased over time, several factors shape this development: party ideology (with progressive parties fielding more youth), the share of incumbents, the total number of candidates, and the type of candidacy; young candidates are notably underrepresented in district races. Furthermore, we find evidence for the ‘sacrificial lamb’ thesis, as young nominees are often placed in lower list positions and less winnable districts than their older counterparts.