Types of Electoral Systems

Types of Electoral Systems

A country’s electoral system is the method used to calculate the number of elected positions in government that individuals and parties are awarded after elections. In other words, it is the way that votes are translated into seats in parliament or in other areas of government (such as the presidency).

There are many different types of electoral systems in use around the world, and even within individual countries, different electoral systems may be found in different regions and at different levels of government (e.g., for elections to school boards, city councils, state legislatures, governorships, etc.). Electoral systems can be divided into three general types:

1. Plurality Systems:

Also called “first-past-the-post” or “winner-take-all” systems, plurality systems simply award a seat to the individual candidate who receives the most votes in an election. The candidate need not get a majority (50%+) of the vote to win; so long as he has a larger number of votes than all other candidates, he is declared the winner. Plurality systems normally depend on single-member constituencies, and allow voters to indicate only one vote on their ballot (by pulling a single lever, punching a hole in the ballot, making an X, etc.) Plurality electoral systems also tend to encourage the growth of relatively stable political systems dominated by two major parties.

Such an electoral system, though, clearly does not represent the interests of all (or even most) voters. In fact, since a candidate need have only a plurality of votes to be elected, most voters may actually have voted against the winner (although their votes are split among several candidates).

Elections for the House and Senate in the United States and for the House of Commons in the United Kingdom use the plurality system. The US presidential election is also generally considered a plurality system, but the existence of the Electoral College actually makes it a strange hybrid of plurality and majority systems.

2. Majoritarian Systems:

Also called “second ballot” systems, majority electoral systems attempt to provide for a greater degree of representativeness by requiring that candidates achieve a majority of votes in order to win. “Majority” is normally defined as 50%-plus-one-vote. If no candidate gets a majority of votes, then a second round of voting is held (often a week or so after the initial ballot). In the second round of voting, only a select number of candidates from the first round are allowed to participate. In some countries, such as Russia, the top two vote-getters in the first round move on to the second round. In other countries, such as France, all candidates with a minimum threshold percentage of votes (in the French case, 12.5% of all registered voters) move on to the second round. Like plurality systems, majority systems usually rely on single-member constituencies, and allow voters to indicate only one preference on their ballot.

Presidential elections in Austria, Finland, Portugal, Russia and other east European states, as well as presidential and National Assembly elections in France, make use of various forms of majority electoral systems. The US Electoral College also has components of a majority system, because a presidential candidate must get 50%-plus-one electoral votes (270 out of 538) in order to win. If no candidate reaches the 270 mark, the election is decided by the House of Representatives. In determining who votes for whom in the Electoral College, though, the US presidential race is a strict plurality system: The candidate who gets a plurality of the popular vote in a state gets all that state’s electoral votes.

3. Proportional Systems:

Also known as “PR”, proportional representation is the general name for a class of voting systems that attempt to make the percentage of offices awarded to candidates reflect as closely as possible the percentage of votes that they received in the election. It is the most widely used set of electoral systems in the world, and its variants can be found at some level of government in almost every country (including the United States, where some city councils are elected using forms of PR).

The most straightforward version of PR is simply to award a party the same percentage of seats in parliament as it gets votes at the polls. Thus, if a party won 40% of the vote it would receive 40% of the seats. However, there are clear problems with such a system: Should parties that receive only 0.001% of the vote also be represented? What happens if the voting percentages do not translate evenly into seats? How do you award a party 19.5 seats if it got 19.5% of the vote? More sophisticated PR systems attempt to get around these problems. The most widely used families of PR electoral systems are party list PR, the single transferable vote (STV), and mixed member proportional representation (MMP).

With party list PR, political parties define candidate lists and voters vote for a list. The relative vote for each list determines how many candidates from each list are actually elected. Lists can be "closed" or "open"; open lists allow voters to indicate individual candidate preferences and vote for independent candidates. Voting districts can be small (as few as three seats in some districts in Chile or Ireland) or as large as a province or an entire nation.

Mixed member proportional representation (MMP), also called the additional member system (AMS), is a two-tier mixed electoral system combining a non-proportional plurality/majoritarian election and a compensatory regional or national party list PR election. Voters typically have two votes, one for their single-member district and one for the party list, the party list vote determining the balance of the parties in the elected body.