proportional representation

proportional representation(PR), an electoral system designed to ensure that the composition of collective bodies reflects accurately the composition of those electing them, especially in terms of their party political make‐up. In its original and simplest form, as it emerged in continental Europe in the 19th century, PR was based on voting for discrete lists of candidates proposed by political parties; seats were allocated to parties by means of a simple mathematical formula in proportion to their share of votes.

An alternative system devised by Thomas Hare in Britain achieved, in adapted form, widespread influence in territories of British influence, beginning with Tasmania (1896) and extending to Ireland for local elections (1919–20) and general elections (1921). This is based on the single transferable vote in multi‐member constituencies; voters rank candidates in order of preference, and seats are allocated to candidates winning an electoral quota on the basis of complex rules for the counting of votes and transfer of lower preferences. The aggregate effect of this system is proportional, in that the political composition of elected bodies tends to reflect closely that of the electors.

This system of PR set down deep roots in independent Ireland. It was incorporated in the constitutions of 1922 and 1937, and survived government‐sponsored attempts in 1959 and 1968 to replace it by the British plurality system, which tends to favour larger parties. In Northern Ireland it was abolished for local elections in 1922 and for elections to the House of Commons in 1929; but it was restored at both of these levels in 1973.

John Coakley