District Population Size and Candidates’ Vote-seeking Strategies: Evidence from Japan

This paper examines whether candidates in Japanese local elections are more likely to declare affiliation with parties as the population size of districts increases, and thus the importance of party reputations and resources for mobilization increases. To test this hypothesis, we use data from Japanese municipal legislative elections between 1999 and 2010 where the vast majority of candidates run as independents. We exploit variations in the population size of districts before and after massive municipal mergers. We find that the percentage of candidates affiliated with political parties increased when the number of votes required for winning a seat increased as a result of municipal mergers. Our analysis also finds that candidates in municipalities that merged were more likely to join parties, compared to those in municipalities that did not experience mergers.