Proportional representation is the idea that seats in parliament should be allocated so that they are in proportion to the votes cast.
Voting systems can be more or less proportional. Those that are described as Proportional Representation (PR), such as Party List Proportional Representation, the Single Transferable Vote and the Additional Member System, have been designed with the aim of being more proportional.
Other systems, known as ‘majoritarian’, such as First Past the Post, the Alternative Vote and Supplementary Vote can be reasonably proportional in the right circumstances, but will usually be very disproportionate.
Different systems of proportional representation have different ways of electing candidates. With some it is possible to vote only for a party, with others directly for candidates.
Rather than the winner-take all approach of other systems, proportional representation ensures that votes carry equal weight. To do this, a single area elects more than one representative. The size of this area can vary according to the system, ranging from the size of the whole country to a county or local area.