Linking individual electoral performance to the composition of elected bodies: A counterfactual-based approach

This research note presents a counterfactual-based approach to assessing the impact of candidates’ personal vote-earning attributes and list properties on the composition of bodies elected under open and semi-open list proportional representation systems. Previous research has focused heavily on individual electoral performance, overlooking the broader implications for descriptive representation. By identifying counterfactual electees and juxtaposing their numbers with those of factual electees, the proposed approach provides intuitive metrics of how specific factors alter the composition of elected bodies. Applied to the 2023 regional parliament election of Lucerne, Switzerland, the results suggest that the effect sizes identified in regression analyses of electoral performance do not always correspond to how strongly the respective variables subsequently influence the composition of elected bodies. The counterfactual-based approach thus provides valuable insights into the electoral consequences of candidate and list characteristics, and their role in shaping descriptive representation.