Malapportionment and Voter Turnout: Evidence from Japan

Malapportionment, disparities in the value of a vote between voters, is one of the most serious problems in elections and representation around the world. While representation and policy bias caused by malapportionment have received considerable scholarly attention, its impact on political participation has been neglected. This study argues that malapportionment discourages underrepresented voters to participate in politics. Using an original data set on six elections for Japan’s upper house from 2001 to 2016, the study finds that voter turnout is lower in underrepresented districts (i.e., districts with relatively more population per legislative seat) than in overrepresented districts (i.e., districts with relatively less population per seat). Furthermore, it examines the impact of reapportionment on political participation. It finds that an increase in the number of seats leads to an increase in voter turnout but a decrease in it has no significant effect on voter turnout.