Small time costs matter: Reform-induced polling station congestion reduces turnout in a high-turnout PR system

Long waiting times at polling stations may reduce voter turnout and potentially undermine democratic legitimacy and, if unevenly distributed, democratic equality. Yet their effects on turnout remain poorly understood and have been studied mainly in majoritarian contexts. We provide the first evidence from a proportional parliamentary democracy by examining Sweden’s 2022 general election, when a reform to strengthen ballot secrecy unexpectedly produced congestion at many polling places. We estimate the turnout effect of congestion, using administrative records on precincts’ closing times together with original assessments from poll workers and local election authorities. Across several independent measures and estimation techniques, precincts experiencing problematic lines exhibit turnout about 1 to 1.5 percentage points lower than comparable precincts without congestion. The fact that congestion was induced by an exogenous legislative change and that Swedish voters were unaccustomed to polling station waiting times facilitates causal inference. Our results align with the few existing studies examining the impact of additional waiting times in majoritarian and presidential systems (the US and Kenya), suggesting that voters in a high-turnout PR system react similarly to voters in other contexts to an increased cost of voting. This underscores the policy importance of preventing congestion. Furthermore, our findings highlight a trade-off in electoral management between efficiency and ballot secrecy that warrants more attention in research as well as in electoral reform.