[Constitutional Amendment, Connecting the Future] Among OECD Countries, 6 Including Korea Adopt the Presidential System

Turkey, Chile, and Colombia Use Runoff Voting System
Mexico Elects Winner by Plurality, Same as South Korea

Among the 38 countries in the Organisation for Economic Co-operation and Development (OECD), only six countries, including South Korea, the United States, Mexico, Chile, Colombia, and T?rkiye (Turkey), have adopted the presidential system. The rest of the countries, classified as so-called advanced nations, operate under parliamentary systems or semi-presidential systems, which are power-dispersed systems.

Even among presidential systems, there are differences in how each country operates. In the United States, the four-year renewable term and the bicameral legislature are generally regarded as functioning relatively organically. On the other hand, countries like South Korea, Mexico, Chile, Colombia, and Turkey have shown more drawbacks of the presidential system. South Korea, which has adopted a single five-year term, has deeply rooted a winner-takes-all structure, leading to political conflicts escalating into extreme confrontations becoming commonplace. Other countries have experienced political instability due to coups, dictatorships, and armed conflicts. German constitutional scholar Karl Loewenstein described this by saying, "The presidential system becomes a 'kiss of death' for democracy the moment it crosses the borders of the United States."

The electoral systems for electing presidents also vary. South Korea uses a direct election system where the people vote directly, but the United States uses an indirect election system where electors, directly elected by each state, choose the president. The number of electors varies by state, and the candidate who wins the most votes in a state takes all of that state's electoral votes in a winner-takes-all manner. The U.S. Electoral College consists of 538 members, and securing a majority of 270 or more is considered the "magic number" for victory. This is a unique system that is hard to find elsewhere in the world.

Most presidential system countries, except South Korea and the United States, implement a runoff voting system. If no candidate wins a majority in the first round, a runoff election is held between the top two candidates to elect the president. Turkey, Chile, and Colombia elect their presidents this way. Semi-presidential countries like France and Poland also hold runoff elections between the two candidates with the highest votes if no candidate achieves a majority.

Some countries, such as Argentina, conduct runoff elections even if a candidate receives less than or more than half of the votes, which is called a modified runoff system. South Korea also saw the introduction of a runoff voting system become an issue before the last presidential election, but it failed to pass. Mexico, where the president serves a single six-year term, elects the candidate with the most votes without a runoff system, similar to South Korea.

The parliamentary system is a system where the leader of the majority party in the legislature becomes the prime minister and forms the executive branch. Except for Japan, countries with parliamentary systems generally have active multi-party systems, and coalition governments are essential. The executive and legislative branches cooperate with each other, which is the most contrasting feature compared to the presidential system. However, if government formation is delayed, there is a risk of prolonged anarchy. Also, since the majority party controls the executive branch, it is difficult to check the executive.

The semi-presidential system is a hybrid of the presidential and parliamentary systems. In this system, executive power is divided between a president elected by direct vote and a prime minister elected by the legislature. Depending on the characteristics of the country, the semi-presidential system may exhibit more presidential or parliamentary features. Depending on which system's characteristics are more prominent, it is classified as a "decentralized presidential system (anti-presidential system, semi-presidential system)" or a "semi-parliamentary system." For example, France is a decentralized presidential system country with strong presidential powers. In contrast, Austria's national system is classified as a semi-parliamentary semi-presidential system because the president's actual powers are very weak.