Electoral Systems and Geographic Representation

Who gets represented in legislatures, and how does this depend on electoral institutions? Others have asked this 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 sixty-two democracies, we developed a new measure to determine whether the spatial distribution of MP birthplaces matched the spatial distribution of the citizens they represented. Contrary to received wisdom, 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 the contamination effects in their single-member tier. We present evidence for this explanation from a within-country analysis of elections in Italy, the UK, and Germany.