All 300 seats in South Korea's unicameral National Assembly are up for election on 14 April. 246 members are elected in single-member, first-past-the-post (FPP) districts, while the remaining 54 seats are elected on a separate ballot via proportional representation (PR). The vote comes amid a tense security situation on the peninsula. North Korea's many provocations this year, including a fourth nuclear test in January, have made national security much more salient than normal. Elsewhere, Korea's export-driven growth continues to stumble amid a cooling-off period in Chinese development and a weaker yen. Youth unemployment remains high.

South Korea's electoral law

Despite the tough situation on the ground, the ruling Saenuri Party (새누리당, or 'New Frontier Party') is in good shape heading into the elections. Korean President Park Geun-hye has enjoyed steady approval ratings around 40%, despite a number of scandals at home and an unpopular comfort women deal signed with Japan late last year. Within her own Saenuri Party, her approval rating is an impressive 78%. 

Saenuri currently holds a 152-127 majority in the National Assembly. Like its President, the party has also remained popular. Saenuri is up 5% since January, polling at 41.5% approval. It has maintained an average favorable opinion lead of 14.6% over the main opposition Minjoo Party of Korea (더민주, or 'Together Democratic Party'), currently polling at 28.6%. Korea's voting system for the National Assembly is similar to the German Bundestag. It is a mix of proportional representation (PR) and first past the post (FPP) single-member districts. The FPP seats dominate the Assembly and, following Duverger's Law, have created a mostly two big-tent party system between Saenuri and Minjoo.

However, the existence of a handful (18%) of PR seats routinely tempts outsiders and malcontents to form mini-parties nipping at the heels of the two majors. In 2012, a total of 25 parties were registered with the national election commission right before the election. That number shrank to seven right after the 2012 general election. As of the time of writing, there are 23 parties registered in Korea, up from 16 a year ago. The PR seats offer the only realistic representation chance for these small outfits. 

The upshot is what one might call a 2+ party system, in which the PR seats regularly seduce political entrepreneurs to break with the main parties in personalistic efforts to build their own parties. The formal requirement for representation is not that high — one FFP victory plus 3% of the PR vote (by contrast, Germany requires 5% of PR and Turkey a punishing 10% to enter the legislature). And in this cycle, this is precisely what has happened; left-wing entrepreneur Ahn Chul Soo has broken from Minjoo after a lengthy high profile leadership struggle, to form his own Goookmin Party (국민의당 – literally the 'People's Party'). 

The South Korean left and Duverger's Law

PR-driven factionalism has plagued Korean political parties for decades; Korea always seems on the cusp of an American-style two-party system but never quite gets there. Notably though in recent years, the left has suffered from this much more than the right, particularly since its crushing defeat in 2008. Ahn and Minjoo barely submerged their differences for the 2012 Korean presidential election, and nearly two dozen Minjoo politicians have recently defected to Gookmin, including party co-founder Kim Han-gill. Ahn has also strictly ruled out coalitions between Minjoo and Gookmin. This will threaten Minjoo's ability to win FPP seats, because the left's vote will now split. Nevertheless, Ahn's party should cross the low representation threshold to enter parliament. This prediction in turn raises the biggest issue of the election: factionalisation on the left may 'throw' perhaps a dozen or more FPP Assembly seats, which the left should otherwise win, to the right. If Ahn does not change course soon, I predict a large Saenuri victory.

The logic of Duverger's Law is very clear and powerful here: splitting ideologically similar voters across multiple similar parties allows the other side, if it stays concentrated in one big tent party, to win an FPP race. The most famous example of this is the 2000 US presidential race in Florida. There the combined left of Ralph Nader (Green Party) and Al Gore outpolled George Bush. Bush took the state anyway, because Nader drew voters from Gore, thereby giving Bush the most votes and 'throwing' the election to the right.

This logic repeats itself regularly in Korea too, where conservatives have a better record of realising that the large predominance of FPP seats in the Assembly incentivises party discipline and punishes factionalisation. Korea does not have a formal party primary system, but Saenuri's internal losers for leadership and the presidential candidacy have notably not exited in recent years, creating threats to otherwise safe Saenuri districts (minor, short-lived exception here). Ahn promises to do exactly that this year to the left, a dynamic that has plagued the (not)unified left for many years already. In the past, schisms on Minjoo's left were a routine problem, as 'progressive' voters flirted with an openly pro-North Korean party. That party, the Unified Progressive Party, received 10% in the last legislative election, before it was broken up as unconstitutional by the Korean high court in 2014.

Why the left especially?

The inability of the Korean left to get its act together, its constant drama of division and infighting, is a recurrent theme in Korean politics. Why is a great question for any  graduate student working on Korean domestic politics. Here are my own two hypotheses:

  1. The Korean left intensely dislikes authoritarianism, and that reduces the party discipline FPP races requires. The Korean left has a long, admirable history fighting right-wing authoritarians in the Republic of Korea's history. In the democratic period since 1987, it has continued to fight for important liberal causes such as the expansion of press freedom and limits on domestic surveillance where the right's record has been often embarrassingly bad (under Korea's last two conservative presidents, the ROK's press freedom score from Freedom House has slipped badly). Perhaps this undercuts the ability of left-wing leaders to tell others to get in line; that rings of the bad old days.
  2. Saenuri is unified around issues as the left is not, and that undercuts right-wing entrepreneurship, because the entrepreneur would not add anything which the main candidate is not already saying. As the chart below suggests, Saenuri voters are tightly clustered around hawkish foreign policy beliefs and character, while President Park's opponents are all over the place on preferred issues.

Other hypotheses welcome!

Photo by Chung Sung-Jun/Getty Images