Measuring the Malapportioned Effects of Redistricting in Korea

Abstract

This study measures the effects of malapportionment in the 17th (2004) and the 18th (2008) National Assembly elections in Korea, using the unequal weighted index (UWI) and the Loosemore-Hanby (L-H) index. The ratio between the most-populous district (MPD) and the least-populous district (LPD) increased from 2.80:1 in the 17th election to 2.96:1 in the 18th election. The number of districts close to the national average population decreased in the 18th election in terms of the UWI. The L-H index of the single-member district (SMD) system increased from 3.68 to 4.10. Changes in these figures indicate that the effects of malapportionment became worse in the 18th than in the 17th election. But an observation was made of the fact that the adoption of the proportional representation (PR) system slightly mitigated the malapportioned effects caused by the SMD system alone. In order to decrease malapportionment in Korea, revision of redistricting mechanisms should include establishing an independent Electoral Redistricting Commission (ERC), setting the population criterion below 2:1 between the MPD and the LPD, adopting redistricting technologies to increase compactness of districts, and enhancing the roles of judicial institutions and social civic groups.