Election 2011 Referendum
Referendum on the electoral system
On 26 November, you'll be asked two questions on the system used to elect Members of Parliament.
- Should New Zealand keep the Mixed Member Proportional (MMP) voting system?
- If New Zealand were to change to another voting system, which voting system [of four other options] would you choose?
You can answer both questions, regardless of your vote in the first question.
What happens as a result
If a majority of voters choose to keep MMP, the Electoral Commission would in 2012 carry out an independent review of most aspects of the system, other than the number of seats in Parliament and the future of the Māori seats. Matters it would consider include the thresholds parties must meet to be eligible for list seats, whether voters should have the ability to alter the rankings of candidates on a party list and whether candidates can stand in both an electorate and on the party list.
If voters reject MMP, Parliament would then decide whether to hold a further referendum in 2014 to choose between MMP and the most popular alternative system identified by voters in the second question.
The voting systems: what they have in common
While all five systems vary in design and effect, two major features are the same in each one. All elect a Parliament of 120 MPs and each system includes Māori electorates.
Insight hosts a public debate on MMP, moderated by Philippa Tolley and Julian Robins.
A forum exploring the issues involved with the Electoral Referendum, hosted by Dr Claudia Orange.
What are the options?
Mixed Member Proportional (MMP)
This is the present system and has been in place since the 1996 election. It is a system of proportional representation. Under MMP it is unusual for a single party to win a majority of seats in Parliament and coalitions or support deals between parties are usually needed to form a government.
Each voter gets two votes: one for a political party and one for their local electorate MP.
The party vote largely decides the overall make-up of Parliament, and how many MPs each party will get. The second vote determines the local electorate MP and the candidate who gets the most votes wins.
Under current rules, political parties make it into Parliament if they get 5% of the party vote or win at least one electorate seat. The seats in Parliament are distributed such that each party gets roughly the same share of seats as its share of the party vote. For example, if a party gets 40% of the party vote it will get roughly 40% of the seats in Parliament - or 48 seats. If that party had won, say, 30 electorate seats it would then be allocated 18 list MPs.
Under the present MMP system there are 70 electorate MPs and 50 list MPs.
First Past the Post (FPP)
This was the electoral system used in New Zealand up until the switch to MMP in 1996. First Past the Post tends to result in a single party being able to form a majority Government. It usually delivers the winning party a greater share of seats in Parliament than its proportion of overall votes across the country. Smaller parties usually receive a smaller share of seats than their proportion of the votes.
Each voter gets one vote, to pick their local Member of Parliament. The candidate who gets the most votes wins. The candidate is not required to win more than half the votes to be elected. Parliament is made up of 120 electorate MPs.
Preferential Voting (PV)
Preferential Voting usually delivers single-party majority Governments. Like First Past the Post, it tends to give the winning party a greater share of the seats in Parliament than its share of votes across the country. Smaller parties usually receive fewer seats than if they were distributed according to the share votes.
There are 120 local electorates, each electing one MP. Voters rank the candidates (1, 2, 3 etc) in the order they prefer them. To win, a candidate must get more than half of the votes cast. If no-one gets a majority of first preference votes, the candidate with the fewest number "1" votes drops out of the running and their votes are distributed to other candidates based on voter rankings. This process is repeated until one candidate secures more than half the votes.
Single Transferable Vote (STV)
STV is a form of proportional representation and coalitions or support deals between political parties are usually needed before governments can be formed.
This is an electorate-based system but instead of electing a single local MP voters in each seat will elect between 3 and 7 MPs. There would be between 24 and 30 multi-member seats across the country. Parties would be allowed to stand more than one candidate in each seat.
Voters get a single vote, however that vote is transferable. Voters either rank the individual candidates in their preferred order, or they can vote for a ranking published in advance by a political party.
MPs are elected by receiving a minimum number of votes, known as the quota. This is calculated based on the number of votes in an electorate and the number of MPs to be elected in that electorate.
Candidates who get enough first preference votes to reach the quota are elected. If there are still electorate seats to fill, votes over and above the quota received by candidates already elected are transferred to other candidates, according to voter rankings. Then, if there are still electorate seats to fill, the lowest polling candidate is eliminated and their votes are transferred to other candidates, according to voters' rankings.
This process is repeated until all MPs (3 to 7 per electorate) are decided.
Supplementary Member (SM)
Supplementary Member is what is known as a parallel voting system, having a mix of electorate MPs and party list MPs elected by separate votes. It is not a fully proportional system and usually results in single party governments, although coalitions or agreements between parties may sometimes be needed.
Like MMP, voters under Supplementary Member get two votes. There would be 90 electorate MPs chosen by First Past the Post (the candidate who gets the most votes wins but does not need to get a majority of votes cast).
The second vote is for a political party and is used to decide what share of the 30 list MPs each party will receive. Unlike MMP, the party vote does not decide the overall shape of the Parliament as it only applies to the 30 list seats. For example, if a party gets 20% of the party vote it is entitled to 6 list MPs in addition to any electorate seats that it wins, while under MMP the total number of list and electorate MPs for a 20% party vote would be about 24.
Videos from ReferendumNZ - the Electoral Commission on YouTube