New Zealand’s MMP electoral system: how does it work?

Doug Cowan, Head of Digital

Posted on the 14th October 2020

New Zealand actor Jack Buchanan explains how MMP works in this music video created in partnership with the New Zealand Electoral Commission.

Politics in New Zealand can look to outsiders to be much like politics in the UK. For the 2020 election on the 17 October they have two major parties, the left-wing Labour Party and the conservative National Party and a number of minor parties. New Zealand’s 120 representatives are called MPs – although they sit in the House of Representatives rather than a House of Commons. Until 1996 these MPs were elected under First Past the Post – like our MPs – when they ditched the system in favour of Mixed Member Proportional (MMP).

Mixed Member Proportional

Under MMP voters still elect MPs for their local area – called electorates rather than constituencies – but they also have a second vote for a party to use too. It’s this party vote that helps make the parliament representative and proportional so the division of seats accurately reflects the votes cast in the election.

All the MPs that won electorates take their seats first. Then if parties need more MPs to get them up to the level their party’s vote share the MPs come from a list of candidates the party published before the election.

If this sounds similar, it’s because it is like the systems we use in London, Scotland and Wales. In Scotland and Wales though, the proportionality is worked out in regions, rather than nationally.

With 120 seats, a party would need 0.8% of the vote to win a seat. But to prevent having lots of tiny parties, they apply a national threshold of 5%. There is a loophole though where parties that win an electorate can get their MPs into parliament even if the party at a whole is on under 5%.

64 MPs come from electorate seats and 49 are selected from the party lists. This leaves seven MPs who are elected from special Māori electorates. These seven seats overlap with the general electorates and voters of Māori descent can choose whether they will vote in the general electorate they live in or the Māori electorate they live in. Māori voters have the same party-list vote as everyone else and can swap between the general and Māori electoral roll every 5 years if they wish.

While in the UK tiny swings in marginal seats decide the result, in New Zealand the way people vote across the board does.

The Road to Reform

New Zealand adopted MMP after a series of spectacular failures of their old, Westminster style electoral system. The birth of a new Social Credit party in the 1970s started showing the weakness of the old system: they got 16% of the vote in 1978 and won just one seat. In 1981 they increased their vote share to 21% but took just two seats in parliament. In the 1984 election, the New Zealand Party won 12% but failed to win a single electorate.

In 1978 and 1981, the Labour Party won more votes than the National Party, but the National Party won most seats and formed the government – making a nonsense of the idea that First Past the Post lets voters kick out the government.

When the public finally got the Labour government they wanted in 1984, Labour created a Royal Commission to investigate the electoral system. The commission recommended New Zealand adopt a German-style Mixed Member Proportional system (MMP, known as the Additional Member System in the UK).

But, many in the government quite liked the power that the artificial majorities of First Past the Post gave them. Sensing an opportunity, the National Party promised a referendum on electoral reform, leading to both parties offering a referendum in the 1990 election.

In 1992, the National Party held a non-binding referendum where 85% voted to change the system, and 70% picked MMP as the replacement. A second, binding referendum was held in 1993 which saw New Zealand vote to bury First Past the Post and adopt MMP.

In 2011, New Zealand held a follow-up referendum and found that support for the MMP system had grown showing clearly that when voters have experienced a fair voting system they aren’t in a hurry to hand back the power.

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