Comparison of electoral systemsComparison of electoral systems is the result of comparative politics for electoral systems. Electoral systems are the rules for conducting elections, a main component of which is the algorithm for determining the winner (or several winners) from the ballots cast. This article discusses methods and results of comparing different electoral systems, both those that elect a unique candidate in a 'single-winner' election and those that elect a group of representatives in a multiwinner election.
Proportional approval votingProportional approval voting (PAV) is a proportional electoral system for selecting committees. It is an extension of the D'Hondt method of apportionment that additionally allows for personal votes (voters vote for candidates, not for a party list). The voters vote via approval ballots where each voter marks those candidates that the voter finds acceptable. The system was first proposed by Thorvald N. Thiele. It was used in combination with ranked voting in the early 20th century in Sweden, for example between 1909 and 1921 for distributing seats within parties, and in local elections.
Multiwinner approval votingMultiwinner approval voting, also called approval-based committee voting, is a multi-winner electoral system that uses approval ballots. Each voter may select ("approve") any number of candidates, and multiple candidates are elected. The number of elected candidates is usually fixed in advance. For example, it can be the number of seats in a country's parliament, or the required number of members in a committee. Multiwinner approval voting is an adaptation of approval voting to multiwinner elections.
Cumulative votingCumulative voting (also accumulation voting, weighted voting or multi-voting) is a multiple-winner method intended to promote more proportional representation than winner-take-all elections such as block voting or first past the post. Cumulative voting is used frequently in corporate governance, where it is mandated by some (7) U.S. states (see e.g., Minn. Stat. Sec. 302A.111 subd. 2(d).). Cumulative voting was used to elect the Illinois House of Representatives from 1870 until its repeal in 1980 and used in England and Scotland in the late 19th century to elect some school boards.
Cardinal votingCardinal voting refers to any electoral system which allows the voter to give each candidate an independent evaluation, typically a rating or grade. These are also referred to as "rated" (ratings ballot), "evaluative", "graded", or "absolute" voting systems. Cardinal methods (based on cardinal utility) and ordinal methods (based on ordinal utility) are two main categories of modern voting systems, along with plurality voting. There are several voting systems that allow independent ratings of each candidate.
