Electoral Systems and Electoral Integrity: A Cross-National and Cross-Temporal Analysis With Policy Implications

This study examines the relationship between electoral systems and electoral integrity across a panel of 1,641 elections held in 141 countries over the period 1832–2024. Employing a correlated random-effects framework, which simultaneously recovers within-country estimates equivalent to fixed effects and between-country estimates capturing stable structural differences, the analysis reveals that proportional representation is associated with short-run reductions in electoral integrity within countries over time, reflecting administrative complexity, diffuse accountability costs, and the institutional turbulence that typically accompanies electoral system transitions. Yet countries with persistently proportional electoral systems exhibit substantially higher electoral integrity in cross-national comparison, reflecting the long-run co-evolution between proportional representation institutions and integrity-sustaining democratic infrastructure. These divergent effects cannot be recovered by cross-sectional or pooled analyses, which conflate two opposing mechanisms. The study shows that while proportional representation ultimately benefits electoral integrity when its full range of benefits is materialized in the process of co-evolution with democracy, the short-term transitional effects should not be overlooked.