Voters are often wealthier, more conservative, and better educated.

Postal Ballot Expansion & Political Participation:

Swiss referendums saw increased turnout following postal voting reforms.

• Target Audience: All voters across political spectrums benefited equally from expanded postal voting access.

But the composition of those who voted changed in unexpected ways:

• Increased Representation? No, high-income earners, medium-educated citizens, and casual voters were disproportionately mobilized by this reform.

This suggests that while participation may rise overall,

the diversity of voices at the ballot box remains limited.

Our findings using $N=79k$ individual-level data from 1981-2009 highlight how even seemingly universal reforms can subtly reshape democratic engagement.