proportional representation (PR)

Proportional representation refers to a family of electoral systems which stress the importance of ensuring that the proportion of seats won by a party in a representative assembly reflects as closely as possible the proportion of votes won by the party.  These systems often use more complicated procedures than other electoral systems for counting votes and allocating seats, but the basic principle on which they are based is straightforward—a representative assembly should reflect the distribution of opinion in the political community as closely as possible.  There are two broad ways in which proportional representation can be achieved: the list system and the single transferable vote (STV) system.  Proportional outcomes can also be achieved by mixing proportional representation with a non-proportional system; see mixed member proportional (MMP) systems.  See also mixed systems ; seat share ; vote share .

Some of systems of proportional representation can be called quota preferential systems because they use quotas for working out which candidates are to be elected (see threshold ).  All systems of proportional representation require multimember districts or at large elections.