proportional representation

Electoral system in which share of party seats corresponds to their proportion of the total votes cast, and minority votes are not wasted (as opposed to a simple majority, or ‘first past the post’, system).

Forms of proportional representation include:

party list system (PLS) or additional member system (AMS). As recommended by the Hansard Society in 1976 for introduction in the UK, three-quarters of the members would be elected in single-member constituencies on the traditional majority-vote system, and the remaining seats be allocated according to the overall number of votes cast for each party (a variant of this, the additional member system, is used in Germany, where half the members are elected from lists by proportional representation, and half compete for single-member ‘first past the post’ constituencies). Proportional representation is used for the new Scottish Parliament and National Assembly for Wales, both first elected in 1999, and, also since 1999, for European Parliament elections in Britain. For the European Parliament elections, ‘closed’ regional party lists (in which voters cannot change the order of candidates on a party's list) are used and seats allocated in proportion to each party's regional vote. The system allowed the environmentalist Green Party and the anti-European Union UK Independence Party to win European Parliament seats for the first ever time, in June 1999. For the Scottish Parliament and Welsh National Assembly elections, more than half of the members are returned by first past the post from single-member constituencies, with the remainder being drawn, by means of ‘top-up’ proportional representation from regional party lists. This ‘additional member system’, which gives electors two votes, is similar to that used in German elections. It has also been used, since May 2000, for elections to the Greater London Assembly.

single transferable vote (STV). Candidates are numbered in order of preference by the voter, and any votes surplus to the minimum required for a candidate to win are transferred to second preferences, as are second-preference votes from the successive candidates at the bottom of the poll until the required number of elected candidates is achieved. This is in use in the Republic of Ireland and for European Parliament elections in Northern Ireland. It has also been used since June 1998 for elections to the Northern Ireland Assembly.

alternative vote (AV). Not strictly a form of proportional representation, since it cannot guarantee a close relationship between votes and seats, the AV is a system which is simple and can make the voting system fairer. It is based on single-member constituencies in which the elector receives two votes: a first vote, to be marked ‘1’, for the preferred candidate, and a second, to be marked ‘2’, for a second choice. If no one candidate collects more than 50% of the ‘first preference’ votes, the candidate with the fewest of first choice votes is eliminated and his or her ‘second preference’ votes are allocated among the remaining candidates. This process continues until one candidate emerges with at least 50%. The system is used in Australian House of Representatives elections. Termed the Supplementary Vote (SV), it has also been used since May 2000 to elect the Greater London mayor.