Woojin Moon, "Decomposition of Regional Voting in South Korea: Ideological Conflicts and Regional Interests," Party Politics, 11 (September, 2005), 579-599.

First Paragraph:
According to modernization theory, urbanization, universal education and development of transportation and communication lead to the integration of ethnic, linguistic and regional divisions in a country (Almond and Verba, 1963; Deutsch, 1961). Recent political development in South Korea, however, has unfolded in the opposite direction: two parties have dominated each of two southern regions since the 1987 democratic reform. In the 16th National Assembly election (NA election, hereafter) in 2000, the ruling New Millennium Democratic Party won 66.8 percent of the vote in the southwestern region (Honam) occupying 25 of the 29 seats. The opposing Grand National Party won 56 percent of the vote in the southeastern region (Youngnam) and swept into 64 of the 65 seats..

Figures and Tables:
Table 1. Proportions of the natives and immigrants in each region
Table 2. Voting decisions of a voter facing the two regional parties
Figure 1. The effect of regional benefits on voters' voting decision
Table 3. Ideological and regional components of electoral support of regional candidates
Table 4. Ideological and regional components in extra regional support
Table 5. Probability of supporting the ruling party in Honam and Youngnam
Table 6. OLS estimates predicting regional voting
Table 7. OLS estimates predicting regional voting without IDEOLOGY

Last Paragraph:
The electoral mechanism that I offer in this article offers an answer: the impeachment of President Roh before the 17th NA election made the difference between the GNP and the two liberal parties more salient than the difference between the GNP and the NMDP.12 Thus, liberal voters who had seen little ideological difference between the GNP and the NMDP had voted for their regional party (the GNP) in the 16th NA election, but now voted for the UP or the DLP in the 17th NA election because they found the ideological positions of these two liberal parties more congruent with their ideology than the NMDP. That is, liberal voters who had been swayed by regional interests due to little ideological difference between the GNP and NMDP in the 16th NA election now voted for the UP or the DLP based on ideology. In sum, the more salient the ideological differences between parties, the more ideological voting is encouraged.