Electoral system

An electoral system is a set of rules used to decide the results of an election. These rules help choose leaders in governments, businesses, nonprofit organizations, and clubs.

The rules cover things like when elections happen, who is allowed to vote, who can stand as a candidate, and how votes are given and counted.

Some elections choose one winner, like a president, while others pick many winners, such as members of a parliament. When picking a group of leaders, areas might be split into smaller parts called constituencies, each with its own representative, or everyone might vote together to choose all representatives at once. Voters can choose a person directly or pick a list of candidates from a political party or alliance.

People who study voting rules come from many areas, like economics, political science, computer science, and mathematics. They have found important ideas about how voting systems work.

Types

Main articles: List of electoral systems and List of electoral systems by country

Electoral systems are the rules we use to decide who wins an election. There are different types of these systems. Some choose one winner, while others choose many winners at once. Some systems make sure that the number of seats a party gets matches how many votes they received, which is called proportional representation. Others give all the seats to the party or person with the most votes, called winner-take-all.

Single-winner and winner-take-all systems

When only one person is chosen as the winner, the system is called winner-take-all. This also applies when one person is chosen from each area, or district. If many people are chosen from one district, sometimes only one party’s candidates win, which is also a kind of winner-take-all.

Plurality voting - first past the post and block voting

Plurality voting is when the person or people with the most votes win, even if they don’t get more than half of all votes. When there is only one position to fill, this is called first-past-the-post. It is commonly used for choosing leaders of countries and for some local elections. In some places, voters can choose many candidates at once, and the ones with the most votes win, whether they have a majority or not.

Runoff systems

A runoff system makes sure that the winner gets more than half of the votes. This can happen in a second round of voting if no one gets a majority in the first round. Sometimes, voters rank candidates, and if no one wins in the first round, the lowest-ranked candidate is removed, and their votes go to the next choice. This continues until someone has a majority. Another way is to hold a second round of voting with only the top two candidates from the first round.

Positional systems

Positional systems give points to candidates based on how voters rank them. One common system is called first-preference plurality, where the candidate with the most first-place votes wins. This is used in some places to choose representatives for smaller groups.

Multi-winner systems

Multi-winner systems are used when more than one person needs to be chosen. Some of these systems make sure that the number of seats a party gets matches how many votes they received. Others do not always match exactly.

Proportional systems

Proportional representation is when the number of seats a party gets is close to the percentage of votes they received. This is used in many countries to choose members of their parliaments. In some systems, voters choose a party and also a specific candidate. In others, voters only choose a party.

Mixed systems

Some countries use mixed systems, where part of the group is chosen by one method and part by another. This can help make sure that the number of seats a party gets matches their share of votes more closely. In some places, if a party wins more seats in one way than they should based on votes, extra seats are added for other parties to balance it out.

Primary elections

Primary elections are when political parties choose their candidates before the main election. This helps make sure that each party has only one candidate running for a position.

Indirect elections

Some elections do not have a direct vote by the public. Instead, another group chooses the leader. For example, in some countries, the leaders are chosen by lawmakers. In the United States, people vote for members of an electoral college, who then choose the president.

Rules and regulations

Electoral systems have rules that help decide how elections are run. These rules are often in a country's constitution or electoral law. They cover who can join the race, who can vote, and what kind of voting tools are used like paper ballots or machine voting.

Some rules decide who can vote and who can be candidates. Most places let almost everyone vote, but the age to vote can change. Some places require voting by law. There are also rules about how areas are divided for voting.

History

Pre-democratic

In ancient Greece and Italy, people had simple ways to share their ideas a long time ago. In early monarchies, kings asked their people for their thoughts on big decisions. People showed their opinions by clapping, shouting, or hitting spears on shields.

Early democracy

Voting became part of democracy around the 6th century BCE in Athenian democracy. But voting was not the main way to pick leaders. Athenians thought talking in groups and picking leaders by chance worked better. They mostly voted by raising their hands, except for serious issues like lawsuits or deciding who to exile for ten years. These were decided by secret ballot. In Rome, people voted in groups, but this could be unfair. Laws were made to use written votes instead.

Development of new systems

In 1770, Jean-Charles de Borda suggested a new way to count votes called the Borda count. Another thinker, the Marquis de Condorcet, suggested a different method. Later, many new ways to count votes were invented. In the 18th century, rules for sharing seats in governments were created because of the United States Constitution.

The single transferable vote (STV) was created in the 1800s in Denmark and the United Kingdom. It was first used in Denmark in 1856 and later in other places.

Single-winner innovations

New ideas for picking one winner appeared in the late 1800s. One of these was instant-runoff voting (IRV). Later, more methods were invented based on old ideas. Ranked voting began to be used in some places like Australia.

Recent reform efforts

In the 1990s and 2000s, many places tried new voting systems. New Zealand changed its system in 1996. Some cities in the United States tried IRV, and St. Louis voted to use approval voting in 2020. However, not all changes stayed. Some places went back to older voting methods because they thought the new ones were too hard to understand. In 2024, many U.S. states voted against changing their voting systems.

Comparison

Main article: Comparison of electoral systems

Electoral systems can be compared in different ways. One way is to use math rules to see if a system works well, but this might not always be practical. Another way is to pretend to hold many elections and see how often a system does not work as hoped. This helps us understand real problems.

We can also look at real elections to see how well different systems work. Things we can check include how easy it is to count votes, how many people vote, and how new groups can get started in politics.

Experts who study voting systems have their favorite ways of voting. Their top choices include mixed systems where some votes help pick many leaders at once, and others help pick one leader each.

Systems by elected body

Main article: List of electoral systems by country

Countries and groups have different ways to choose their leaders or team members. These rules decide who can vote, how votes are counted, and what the results mean. These systems help make fair choices, whether it's picking a country leader or a team captain.