Electoral reforms and the representativeness of turnout

Voters tend to be richer, more conservative, and more educated than non-voters. While many electoral reforms promise to increase political participation, these policy instruments may have multidimensional and differential effects that can increase or decrease the representativeness of turnout. We develop an approach that allows us to estimate these effects and assess the impact of postal voting on representational inequality in Swiss referendums using individual-level ($N = 79,\; 000$) and aggregate-level data from 1981 to 2009. We find that postal voting mobilizes equally across a wide range of political and sociodemographic groups but more strongly activates high earners, those with medium education levels, and less politically interested individuals. Yet, those who vote are not less politically knowledgeable and the effects on the composition of turnout remain limited. Our results inform research on the consequences of electoral reforms meant to increase political participation in large electorates.