Birds of a feather flock together? The survival of underrepresented groups within parliamentary parties, 1991–2015

This study focuses on the exit of MPs of underrepresented groups – that is, women, visible minorities and the lower educated– from parliamentary parties. Research has mostly focused on what brings these politicians into parliament, but not on what determines their survival within parliamentary parties. Based on the economic and sociological literature on organisations, we develop the homophily hypothesis, positing that MPs from underrepresented groups will be more likely to exit their parliamentary party if their share within the parliamentary party is low. Utilising the PATHWAYS dataset, based on 5,889 unique MPs that served during 37 legislative periods across eight Western European countries between 1991 and 2015, this hypothesis is confirmed. These findings have important implications for the literature on descriptive representation and legislative turnover