Plurality

An electoral system in which the first place candidate - even short of an absolute majority - is elected. Most commonly applied in systems with only one seat per electoral district, although in some cases multiple seats may be awarded as a block to the first place party. Also known as 'relative majority,' or 'first-past-the-post.'

Absolute Majority

Proportional representation (PR)

An electoral system that attempts to match the percentage of seats received in a legislature to the percentage of the vote won by each party. Proportional representation systems have multi-member districts and parties are awarded a percentage of those seats based on their electoral results. Many different variations of the basic proportional representation principle exist, which have the effect of making systems relatively more or less proportional.

Closed list PR

A system of proportional representation voting in which the party determines the order of candidates on an electoral list for a multi-member district. Voters choose the party, but the party chooses which candidates have high-ranking positions on the list (and are therefore more likely to be elected within the percentage of seats the party wins).

Open list PR

A system of proportional representation voting in which voters can influence the order of candidates on the party's electoral list. The candidates who receive the most votes rank higher and are elected first within the party's percentage of seats.

District magnitude

A term referring to the total number of seats available in a given electoral district. May range from one (for example, in plurality systems) to the entire legislature (if there is only one national district).

Threshold

In proportional representation systems, the percentage of the vote that a party must earn in order to be eligible for seats under proportional representation rules. Typically used to reduce the number of very small parties in the legislature.

First minority principle

An electoral rule which awards one or more to the party finishing second. Typically combined with plurality elections in which a larger number of seats go to the first place party.

Quotas

Any of a number of systems that require reserving a certain number or percentage of seats for candidates from demographic groups considered to be under-represented in national legislatures (for example, women and minorities).

Concurrent elections

National elections are concurrent when elections for the executive and the legislature take place on the same day. Some systems are only partially concurrent, if part or all of the legislature is renewed before the end of a presidential term.