Electoral system – NZ 2014

New Zealand’s electoral system changed quite dramatically in 1996. Since that year, New Zealand’s Parliament has been elected by the Mixed Member Proportional (MMP) system.

Mixed Member Proportional is a system where a majority of MPs are elected by first-past-the-post to represent a local electorate, and the remainder of MPs are elected as a “top-up” on national party lists. A similar system is used for German elections, and elections to the Scottish Parliament, Greater London Assembly and Welsh Assembly.

New Zealand is divided into 64 ‘general electorates’ which cover the entire country: 48 seats on the North Island and 16 on the South Island. Each of these 64 electorates elects a single MP by a first-past-the-post vote. This is an increase of one seat compared to the 2011 election. Read more about the recent redistribution of electorates.

In addition, New Zealand is divided into seven Māori electorates, that also cover the entire country. Māori voters are given the choice (when they first enrol, and then once every five years) as to whether they wish to be enrolled on the “general” roll, or the “Māori” roll. Voters on the Māori roll vote in these Māori electorates, not in the local electorate where they live. These electorates were first created in 1868. For most of New Zealand history, these electorates were fixed at four, regardless of the number of voters enrolled in those electorates. Since 1996, the number of Māori electorates is determined to give them a similar population to the general electorates. This saw a fifth electorate created in 1996, a sixth in 1999, and a seventh in 2002.

These seventy-one electorates elect seventy-one MPs, and the remaining 49 are filled as “list seats”.

Each voter casts two votes: an “electorate vote” for a candidate in their own seat, and a “party vote” for one of the nationally-registered political parties.

Any party that wins at least one electorate, or wins 5% of the national party vote, qualifies to win list seats.

Parties that pass this “threshold” are then allocated a proportional share out of the total of 120 seats, according to the Sainte-Laguë formula.

The number of list seats that each party wins is calculated by subtracting the number of electorate seats that party won from the total number of seats a party was entitled to win.

For example, if a party wins enough of the party vote to be entitled to twelve seats, and the party has won two electorate seats, then the party would win ten list seats.

This system means that a party that passes the threshold will win a particular number of seats based on its national party vote, regardless of the number of electorate seats. Two parties that win the same number of party votes will win the same number of seats, even if one party has won a lot more electorates.

Elections NZ have produced a calculator that allows you to enter the number of votes for each party, and the number of electorate seats for each party, to determine what the overall result would be.

List seats are allocated to political party candidates according to the “party list”. Candidates may run for both electorates and on the party list, and most candidates do run on both lists. Candidates who are successful in winning an electorate are removed from the party list before seats are allocated. So if a party wins ten list seats, the seats go to the ten most highly-ranked candidates who have not already won an electorate.

If a vacancy arises for a list seat (such as due to death or resignation), the next eligible candidate on the party’s list from the last election fills the seat. Sometimes the person who is next on the list declines the opportunity, and so the seat continues to be offered to candidates in order until someone chooses to take the seat. This can often result in the unusual situation of an MP who lost their seat at the previous election returning to Parliament later in the term.

If a vacancy arises for an electorate seat, a by-election is triggered. In the last term, six list seat vacancies resulted in another candidate entering Parliament, and two by-elections were held.

Quirks and oddities of MMP

While MMP is a very fair system which results in more votes being critical to the election result, and results in parties being fairly represented in Parliament, it does have some strange features.

Party votes going to waste
Parties that do not clear the threshold do not win any seats at all. A party that narrowly passes the 5% threshold would normally win 6-7 seats, but a party that wins slightly less than that number wins nothing. This can make the arbitrary 5% barrier very important in deciding election results.

In the last German federal election, the centre-right won a majority of the vote, but two of the three main centre-right parties fell just short of the 5% barrier, polling 9.5% of the national vote between them. On the other hand, nearly all centre-left votes were cast for parties that cleared the threshold, so the centre-left won an overall majority in the Parliament.

Recent polling suggests that New Zealand First is on the verge of falling under the threshold, and the result could look quite different depending on whether New Zealand First wins 4.5% or 5.5%.

Since a vote for a party that does not cross the threshold is a wasted vote, many voters may choose to not vote for a party that was in danger of falling short of the threshold, which can make it even harder for the party to meet the mark.

Electorate “coat-tails”
Since a party that wins a single electorate is exempt from the 5% threshold, parties can decide to target electorates for that express purpose. A party that is holding an electorate can take more risks, and while a lower vote will still result in seats being lost, it won’t result in the party being excluded from Parliament entirely. It can also give voters confidence that their vote will not go to waste.

So a small political party that either cannot meet the 5% threshold, or is in danger of falling below the threshold, can devote most of its time, money and attention to a single electorate. This, therefore, makes that one electorate more important than other electorates. It can also result in some parties winning a number of seats despite winning less votes than a party that does not make it into Parliament.

A major political party can also decide to (subtly, or not so subtly) help a smaller ally win an electorate seat to increase the pool of potential allies within the Parliament. If a party is polling enough votes to win four seats, it may be worth it for the major party who is expecting to win that minor party’s support to sacrifice one electorate seat to increase their allies.

All of these factors can be seen in Epsom. A natural National Party seat, the ACT party won the seat in 2005 as a lifeline to stop the party from being eliminated from Parliament. At the last three elections, ACT has entered Parliament thanks to winning Epsom, after not winning over 5% of the party vote.

In 2008 and 2011, the National Party encouraged their voters to cast an electorate vote for ACT, and ensured that the local National candidate was highly placed on the party’s list and would thus win a seat regardless. This produced a strange result in 2011, where a majority of National party voters cast an electorate vote for ACT, while many Labour and Green voters voted for the National candidate to try to block ACT from returning to Parliament.

A review of the MMP electoral system prior to the 2011 election recommended that this loophole be abolished – by lowering the threshold from 5% to 4%, and by giving list seats only to parties that poll over 4%, regardless of electorate results.


What happens if a party wins more electorates than their total seat entitlement? If this happens, an extra seat (an ‘overhang’) is created in the Parliament for that party.

The Māori Party has caused an overhang at the last three elections. In 2011, the party was entitled to two seats, but actually won three electorates. So the Parliament was increased from 120 seats to 121. In 2008, the Māori Party won five electorates but was only entitled to three seats, so the Parliament consisted of a record number of 122 seats.

There is a danger that a party could win an electorate seat but win such a low party vote that they are not entitled to any seats at all. Polling suggests this is a possibility for ACT and United Future, if they win their electorate but very few party votes.

Spoilers in electorate races

As long as a party is definitely going to qualify for list seats, there is not a significant problem with “spoilers” for the national party vote. A vote for any electable party will help strengthen that political position in the Parliament.

However the use of first-past-the-post for electorates means that spoilers can be a problem in local elections. A strong third-party candidate can draw votes away from the candidate closest to them, and result in a less friendly candidate winning.

In recent elections, the National Party has dominated the centre-right vote while Labour has taken a smaller part of the centre-left vote, in part due to the strong vote for the Green Party. There are a number of electorates held by the National Party where the combined Labour-Green vote is higher than the National vote.

This phenomenon means that the Greens focus their campaigns specifically on winning party votes, and local candidates do not actively seek electorate votes for themselves.

This effect is not as significant as it could be, because of the next factor.

Most local electorate races don’t matter to the national result

Unless you live in an electorate that is relied upon by a party to enter Parliament, your local electorate vote will have no impact on the number of seats each party holds in Parliament. Of course, the local candidates will care, and it can result in different people holding a party’s seats in Parliament, but it will not affect whether Labour or National leads the government, or who becomes Prime Minister.

In one way, this is a good thing – it doesn’t matter if you live in a marginal seat or a safe seat, it’s the party vote that matters, and everyone’s vote counts equally to that result. But it does make local races for particular electorates more low-stakes, and in a way a bit of a distraction from the main game.