Estimating Partisan Effects of Voter Turnout in Japanese National Elections

Abstract

What, if any, impacts does voter turnout have on electoral outcomes? A widely held view in Japan regards organization and mobilization as major determinants of voter participation, stating that heavier turnout decreases vote shares of parties with organized support bases and benefits parties depending on independent and floating voters. This paper estimates partisan effects of turnout rate in the ten national elections held from 2001 to 2014. The results lend no support to the “common-sensical” view and suggest that organization and mobilization are at best a part of causal mechanisms of turnout effects. The findings include that turnout has different effects in upper- and lower-house elections. For instance, the effect on the Liberal Democratic Party’s vote share tends to be positive in the former and negative in the latter. This difference shows that turnout effects stem from a change in defection rate of partisans as well as a change in partisan composition of voters.