Electoral Systems and Geographic Representation

The Moynihan Institute of Global Affairs' Comparative Politics/International Relations Series presents Andrew Eggers. Who gets represented in legislatures, and how does this depend on electoral institutions? Others have asked question from the perspective of gender, race, and class; we focus on space, asking whether MPs disproportionately come from some places rather than others and how this depends on electoral rules. Using data on over 13,000 legislators in 62 democracies, we develop a new measure of the extent to which the spatial distribution of MP birthplaces matches the spatial distribution of the citizens they represent, and we consider how it relates to the electoral system and other local attributes. Contrary to received wisdom, we find that single-member district systems do not have more geographically representative parliaments than multi-member district systems, while mixed-member systems perform significantly better than both. We attribute the higher spatial representativeness of mixed-member systems to contamination effects in their single-member tier, and we present evidence for this explanation from within-country analysis of the UK, Germany, and Italy.

Andrew Eggers is a Professor at the University of Chicago's Department of Political Science and Senior Research Fellow at Nuffield College, Oxford. His research and teaching focus on research methodology, representation, electoral systems, and money and politics.