District Competition in Japan’s 2014 Election: The Roles of Nominations, Incumbency, and Dual Listing

Abstract

Duverger’s Law expects two-party competition in single member districts (SMDs), but evidence from mixed member systems is less consistent with these theoretical expectations. Rather than simply focusing on whether Japan’s most recent House of Representatives election converges toward Duvergerian equilibrium, this article focuses on three factors within Japan. In particular, how do the roles of major party nominations, incumbency, and dual-listing shape district competition vis-à-vis Duverger? Empirical results find that the lack of a Democratic Party of Japan candidate decreases the effective number of candidates, while the lack of a Liberal Democratic Party candidate, multiple incumbents, and dual-listing correlates with an increased number of candidates. The results suggest that often ignored underlying effects of Japan’s mixed system influences its consistency with theoretical expectations.

DISCLOSURE STATEMENT

No potential conflict of interest was reported by the authors.

Notes

1. An additional legislator, independent Takahiro Inoue, was retroactively sponsored by the LDP.

2. The seat bonus jumps from 19% to 22.5% if the 2009 election, a landslide victory for the DPJ, is omitted.

3. The original district-level data, including incumbency and dual listing, come from Yuki Yanai’s website (see http://www2.kobe-u.ac.jp/~yyanai/jp/resources/).

4. Under a one-vote mixed system, district votes are later aggregated to determined PR seats. Under this format (e.g., Mexico, Lesotho), non-viable district candidates must run in order to boost the party’s chances for PR seats.

5. Parties may specifically assign constituency duties to list members with these future district elections in mind.

6. ENCs, a weighted measure of candidates based on vote share, simply modifies the standard measure of effective number of parties to account for independents (see Laakso and Taagepera 1979).

Additional information

Notes on contributors

Timothy S. Rich

Timothy S. Rich is an Assistant Professor of political science at Western Kentucky University. His research focuses on electoral reform, voting behaviour, and public opinion in East Asia (Taiwan, South Korea, and Japan).

Vasabjit Banerjee

Vasabjit Banerjee is an Assistant Professor of political science at Mississippi State University and a Research Associate in the Department of Sociology at the University of Pretoria. His research focuses on contentious politics, state formation, and domestic sources of foreign policy in developing societies in Latin America, South Asia, and Southern Africa.