In the recent 2022 election, neither of the top two candidates — the Democratic Party’s Lee Jae-myung and People Power Party’s Yoon Suk-yeol — garnered majority support in most pre-election surveys. Both polled below 40 per cent support in the lead up to the ‘unlikeable election’ where corruption allegations and negative campaigning turned off many voters.

In mid-February, People’s Party candidate Ahn Cheol-soo wanted to establish a unified opposition candidate with Yoon, with a public opinion poll deciding which candidate would face-off against Lee. Although Ahn dropped the proposal to merge campaigns after Yoon rejected the public-opinion poll, Ahn agreed to drop out and endorse Yoon two weeks before the election. Yoon ultimately won with 48.56 per cent of the vote.

Runoff elections have had relatively little support from mainstream political parties in South Korea, perhaps because they expect to win a plurality and not benefit from reforms. Yet the Justice Party and the People’s Party supported runoff proposals in 2016, and some South Korean political parties use runoffs to determine their presidential nominees. A runoff system would have likely altered the outcome in 1987, 1997 and perhaps 2017.

Proponents argue that runoffs encourage candidates to build broader support and provide a clear mandate for the election winner. They also argue that runoff elections, as seen in the 2017 French presidential election, tend to produce broadly acceptable winners by marginalising fringe candidates. Empirical studies also find that countries with runoff elections are associated with respect for human rights.

Opponents say that runoff elections increase political tensions, especially in close elections. In 2021, Pedro Castillo narrowly defeated Keiko Fujimori in the Peruvian presidential runoff, with Fujimori supporters demanding the election results be nullified after claiming electoral fraud. South Korea’s free democratic status could help prevent the political instability unleashed by those kinds of runoff elections.

As part of a public opinion survey of conducted by the authors between 18–22 February, 945 South Koreans were asked: “Many countries require a runoff election if no presidential candidate receives an outright majority. Would you support changing the election law in South Korea to require a runoff election if no presidential candidate wins an outright majority?’ A majority of respondents (58.1 per cent) supported a runoff election system, as well as a majority of supporters in the Democratic Party (58.88 per cent), Justice Party (62.07 per cent), People’s Party (66.67 per cent) and those with no party preference (62.86 per cent). Only supporters of the People Power Party were more likely to oppose electoral reform (53.05 per cent).

There were similar results based on what candidate respondents intended to vote for in the election, where a majority of those planning to vote for Yoon did not support a runoff (54.85 per cent). Compared to supporters of Lee (57.61 per cent) and the Justice Party’s Sim Sang Jung (65 per cent), this suggests that Yoon supporters may have been confident about their candidate winning under the current rules.

The results are a departure from survey findings in Mexico in 2021, where majorities from all parties supported the implementation of a runoff system. The difference may be the product of timing, as the former was conducted before a legislative rather than presidential election. Yoon’s small but consistent lead in the polls might also have made the 2022 presidential election an exception, so it remains unclear whether conservatives would be more supportive of runoffs in the future.

Runoff elections are not a cure for all the problems facing democratic voting systems, and they require the support of major political parties. They do not always result in the most popular first round candidate winning the election, potentially causing voter confusion, nor do they necessarily make elections less contentious.

But South Korea could still benefit from runoff reforms if they ensure the winner has majority support, prevent smaller parties from playing a spoiler role, and give South Korean voters greater influence over the political process.

Timothy S Rich is Associate Professor of political science at Western Kentucky University and director of the International Public Opinion Lab (IPOL).

Ian Milden is a recent graduate of the Master’s in Public Administration program at Western Kentucky University.

Madelynn Einhorn is an honours undergraduate researcher at Western Kentucky University.