The 2011 referendum on MMP will ask voters to choose from four voting systems in the event that there is a change from the current MMP system.
The voting systems listed are based on those put to voters in the 1992 referendum on voting systems.
The voting systems were chosen in 1992 after careful consideration of the report of the Royal Commission of Inquiry on the Electoral System, Towards a Better Democracy.
Descriptions of the new voting systems:
First-Past-the-Post (FPP)
Under First-Past-the-Post, voters have one vote for an electorate candidate. Each electorate elects one candidate to represent them in parliament. The winning candidate in each electorate is the one who gains the most votes, that is, a simple majority.
Preferential Vote (PV)
Under Preferential Vote, voters rank the candidates in their electorate in their order of preference. Each electorate elects one candidate to represent them in parliament. The winning candidate in each electorate must have over 50% of the votes cast, that is, an absolute majority. If no candidate has an absolute majority then the candidate with the lowest number of first preference votes is eliminated and that candidates second preference votes are redistributed. This redistribution continues until a candidate has an absolute majority.
Single Transferable Vote (STV)
Under Single Transferable Vote, voters rank the candidates in their electorate in their order of preference. Each electorate elects a number of candidates to represent them in parliament. The winning candidate in each electorate must have over a certain percentage of the votes cast, depending on the number of candidates to be elected. Any candidate who has over the required percentage is elected. If there are vacancies, the first preference votes of the elected candidates above the required percentage are redistributed according to voters' second preferences. If there are still vacancies after redistributing the excess votes, then the votes of the candidate with the lowest number of first preference votes are redistributed according to the second preferences of the voters for that candidate. This redistribution continues until enough candidates have reached the required percentage.
Supplementary Member (SM)
Under Supplementary Member, voters may have either one or two votes. The first vote is for an electorate candidate, who is elected in the same way as First-Past-the-Post. There are also supplementary seats, which may be allocated through either a second vote for a party list, or allocated in proportion to the total number of votes received nationwide by that party's electorate candidates. Only the supplementary seats are allocated in proportion to the number of votes received through the party vote or the nationwide electorate vote. Therefore, the total number of electorate seats and supplementary seats held by a party might not be in proportion to the total number of votes received by that party.
