the single transferable vote

   The Single Transferable Vote (STV) How electoral systems work Single Transferable Vote   Where is STV used?

• All elections in the Republic of Ireland, except elections for the presidency and by-elections which are both conducted using the Alternative Vote.
• Assembly, European and local government elections in Northern Ireland.
• Local elections in Scotland, from 2007.
• The Australian Senate.
• The Tasmanian House of Assembly.
• The indirect elections to the Rajya Sabha, the upper house of India's federal Parliament.
• All elections in Malta.
• Various local authorities in New Zealand.
• Many UK student unions (it is promoted by the National Union of Students as the fairest electoral system), the Church of England and many other private organisations.

      How does the Single Transferable Vote work? The Single Transferable Vote (STV) is a form of proportional representation which uses preferential voting in multi-member constituencies. Candidates don't need a majority of votes to be elected, just a known 'quota', or share of the votes, determined by the size of the electorate and the number of positions to be filled. Each voter gets one vote, which can transfer from their first-preference to their second-preference, so if your preferred candidate has no chance of being elected or has enough votes already, your vote is transferred to another candidate in accordance with your instructions. STV thus ensures that very few votes are wasted, unlike other systems, especially First Past the Post, where only a small number of votes actually contribute to the result.

Pros and cons of the Single Transferable Vote

http://www.electoral-reform.org.uk/?PageID=483