Matter of Opinion
MMP at 30: Promise, performance and the unfinished reform agenda
There is something fitting about the fact that, thirty years after New Zealand's first Mixed Member Proportional (MMP) election, voters will be deciding the fate of the country's first three-party coalition government. MMP was heralded as providing fairer representation, broader participation and more collaborative government. For most New Zealanders, MMP's first three decades would have to be judged a success. Indeed, as messy as it may seem at times, it is hard to imagine a better expression of the system's core promise than a government built on cooperation between three parties. In an age of international populism, MMP also seems to let off some steam before the pot boils over.
But anniversaries are for more than celebration. They are also an opportunity to take stock of what MMP has delivered, what it has changed and where its unfinished business lies.
The rocky road to MMP
The road to MMP was not a smooth one. Although it was the culmination of decades of debate about the fairness and representativeness of New Zealand's electoral system, finally getting MMP was driven as much by political accident as by deliberate design.
The decisive moment for MMP came during a televised leaders' debate before the 1987 election, when then Prime Minister David Lange inadvertently committed Labour to holding a referendum on electoral reform. While Lange's unexpected commitment was never fully embraced by the Labour caucus and was not ultimately delivered by Labour, the genie was out of the bottle. An issue that had long simmered in the background was now impossible to ignore.
Dissatisfaction with the First Past the Post (FPP) system had been growing since the 1970s and 1980s and in 1986, the Royal Commission on the Electoral System concluded that its features had produced increasingly distorted electoral outcomes and recommended adopting MMP.
Seizing on Labour's broken promise, in 1990 National went into the election committed to its own MMP referendum process. Referendums in 1992 and 1993 followed, with 53.9% of voters ultimately backing MMP and setting New Zealand on the path to its first MMP election in 1996.
What MMP has delivered
After three decades and ten elections, three key themes stand out:
- Representativeness: Parliament today is far more representative of New Zealand than it was under FPP, with greater representation of women, Māori, Pasifika and Asian peoples. That was one of the Royal Commission's central objectives, and one MMP has largely achieved.
- Government formation and stability: MMP has proved more stable than many critics feared. Constitutional conventions governing government formation, caretaker government, and confidence arrangements have adapted to accommodate multi-party government and are now well established. Coalition negotiations have also become a regular post-election feature, with governments commonly formed through agreements between parties with different mandates and priorities. These arrangements have not always been frictionless, but they have proved durable: no MMP government has fallen on a confidence vote or failed to pass a Budget.
- Proportionality of influence versus proportionality of representation: MMP ensures that seats in Parliament broadly reflect votes cast, but this does not necessarily translate to influence in government. Under FPP, concerns centred on the ability of major parties to exercise majority power without majority support. MMP has prompted a different concern: whether coalition bargaining can allow minor parties to exercise influence that exceeds their electoral support. Under MMP, a party with a small share of the vote may hold the balance of power and secure significant concessions in coalition negotiations. MMP has therefore altered, rather than resolved, the longstanding tension between electoral support and political influence, shifting it from major party dominance to minor party influence.
The unresolved reform agenda
While MMP has become a settled feature of New Zealand's constitutional landscape and has delivered on many of its objectives, it has not delivered on all its promises. Two subsequent independent reviews of the MMP system have identified several reforms to improve MMP's proportionality. These areas for improvement include:
- The 5% threshold: The 5% party vote threshold to enter Parliament reflects a tension between proportionality and avoiding excessive parliamentary fragmentation. Its impact on representation has been evident in recent elections, when approximately 160,000 votes in 2023 and 250,000 votes in 2020 were cast for parties that failed to cross the threshold. Both the 2012 Electoral Commission and 2023 Independent Electoral reviews recommended lowering the threshold to 4% and 3.5% respectively. Despite these recommendations, no political party has lowered the threshold.
- The one-electorate seat threshold (or "coat-tail provision"): The ability for a party winning an electorate seat to bring additional list MPs into Parliament, even without reaching the 5% party vote threshold, has been widely criticised. Both independent reviews recommended abolishing this rule, which departs from proportional logic by allowing two parties with identical party vote support to receive markedly different parliamentary representation depending on whether one happens to win an electorate. The classic example is the 2008 election, where ACT gained four list MPs after winning the Epsom electorate, while New Zealand First received a higher party vote but no parliamentary representation. Again, this recommendation has not yet resulted in any legislative reform.
- The ratio of electorate to list seats: MMP relies on list seats to ensure Parliament's composition reflects the party vote. Because Parliament ordinarily comprises 120 seats, increases in the number of electorates to reflect population growth have correspondingly reduced the pool of list seats available to restore proportionality. If left unchecked, this risks undermining MMP's ability to deliver proportional outcomes. The reviews recommended fixing the electorate-to-list seat ratio at 60:40, with Parliament increasing in size as needed to preserve that ratio and avoid an even number of MPs.
MMP's next challenges
This election is bringing some of these issues into sharp focus. In particular, the 5% threshold has returned to public attention with The Opportunity Party polling close to, or over, the 5% threshold in recent polls.
As MMP enters its fourth decade, the question is no longer whether the system works. By most measures, it does. The question is whether its settings will continue to evolve so that it can deliver the proportionality and representation it was designed to achieve, or whether those objectives will gradually be eroded by institutional inertia and political reluctance.
If we can learn anything from the path to MMP, it is that electoral reform tends to occur when political incentives and constitutional principle briefly align. Thirty years on, the next phase of MMP's evolution may be waiting for precisely that moment.