On Elections

How people elect parliaments

Double-header weekend for MMP voting system

This weekend sees a unique alignment of the world’s two nations that elect their parliaments by the MMP voting system, with elections in both New Zealand and Germany.

Post-war Germany developed the mixed member-proportional (MMP) voting system in the late 1940s.

New Zealand also adopted the system in the 1990s.

The MMP system – or variants of it – is also used to elect the state assemblies on 13 of the 16 German state parliaments, and the devolved assemblies in Scotland, Wales and London. A system similar to MMP is also currently used to elect the national parliament of Lesotho.

MMP has also previously been used in parliamentary elections in Albania, Hungary, Italy, Romania and Venezuela, but each of these nations abandoned the system at various points between 2005 and 2014.

MMP remains popular with some political scientists, and is a frequently-supported option with electoral reform advocates in the UK and Canada.

At the original home of the voting system, the German Bundestag is filled by 299 members elected in single-member divisions by plurality voting, just as in the first-past-the-post voting system.

The MMP system then doubles that number, by adding additional members to make up a parliament where the number of seats each significant political party wins is equal to its share of the total national voter support.

Voters cast two separate votes, one to establish the national party vote totals, and another to elect the plurality member in the local division.

grapgic - Bundestag ballot paper


A German MMP voting system ballot paper, showing the parallel voting options for the local division elected member (Erststimme, in the left column) and for the national party support tally (Zweitstimme)


In MMP systems, just as in party list systems, the second group of MPs are named from lists submitted by the political parties. MMP systems are typically closed list systems, in which the political parties specify the order of names on the lists, so voters have no direct input into who is appointed to this half of the parliament.

After a few decades using the system, the Germans began to experience an anomaly in which their two major political parties (the CDU and the SPD) would win too many seats.

Where minor parties win a substantial share of the national party-support votes, but the larger parties continue to win the plurality votes in virtually all the local division seats, the total number of local seat MPs can add up to more that the party’s ideal national share.

The German solution was to allow all local seat wins to stand – termed ‘overhang’ places – but increase the number of additional party-list seats to ensure that the ratios of seats of all the parties in the Bundestag were correctly matched to the national party support totals.

As the number of successful minor parties has increased in the past few decades, further refinements to the seat compensation rules have been required by the nation’s constitutional court, to maintain the principle that no group of voters has disproportionally high or low influence on the election results.

These mathematical complications have meant that instead of 299 additional party seats being allocated, the number has had to be increased (it was 331 additional seats at the last German elections in 2013).

The same phenomenon of additional party-allocated seats in parliament occurs in New Zealand and the 15 German states which use MMP.

The British AMS variant of MMP – used in Scotland, Wales and London – applies a different solution, strictly maintaining the intended total number of MPs, but sacrificing where necessary the last few seats in the proportional distribution – seats which are relatively more likely to have gone to a smaller minor party.

In Lesotho the electoral rules simply prevent overhang results by not awarding any additional list seats to parties which have done well in local electoral division wins, in doing so mildly disrupting the proportionality goal of the system.

The calculations for MMP can operate on a whole-of-jurisdiction scale (as in New Zealand and London), or alternatively by using internal state boundaries or other electoral divisions (as is done in Germany and its states, and in Scotland and Wales).

The MMP systems typically use a threshold for parties to get any of the additional allocated seats: they must win 5% of the national votes, or else win one of more of the local districts outright. (The calculations for the British AMS systems, however, do not actually require any strict threshold.)


New Zealand – House of Representatives election Saturday September 23

image - New Zealand Parliament building

The Parliament Building in Wellington (image: wikipedia)

The New Zealand House of Representatives, elected at least every three years, shifted to using the MMP system in 1993.

The change came after a 1992 public referendum in which voters first confirmed that they wanted to abandon single-division plurality voting (84% wishing to do so), and then chose between four options for an alternative voting system (won by MMP – the option supported heavily by the leading Electoral Reform Coalition group – with 70% of the vote).

Despite the overwhelming public support for electoral reform in 1992, the New Zealand government at the time then delayed implementing the reform and insisted on a second referendum vote at the 1993 elections (which were thus conducted under the rejected plurality approach) between just the plurality system and the MMP option. Despite a strenuous defence of plurality voting by the major parties and the business lobby, the MMP option won again more narrowly, with 53% support, and finally went on to be implemented at the following elections.

In 2011 the National Party government attempted the rare move of reversing electoral reform and returning to plurality voting though another referendum, but 58% of voters rejected the proposal.

The New Zealand House of Representatives has 70 divisional seats – 63 general and 7 special Māori seats – supplemented by 50 additional seats allocated to nominees on the party lists.

All polls for the today’s election are consistent in showing that four parties will pass the 5% national support threshold to win seats: the governing conservative National Party and the opposition Labour Party as well as the Green Party and the New Zealand First Party.

In past elections conservative minor parties the Association of Consumers and Taxpayers (ACT) and United Future have also won seats despite falling below the 5% threshold by winning the vote plurality in one local electoral district. The ACT party has repeatedly won the electoral division of Epsom, in Auckland, usually with the National Party running dead deliberately to allow that result.

This tactic has helped maximize the number of conservative MPs entering Parliament, providing the National Party with allies on the floor of the House.

However in recent years public support for both the minor right-wing parties has waned, possibly leaving the National Party without either of its micro-allies after today’s poll.

graphic - New Zealand election map 2014

New Zealand’s House of Representatives: the 70 local division election results (including 7 Māori divisions) at the 2014 elections (graphic: Wikipedia)

One additional feature of the New Zealand Parliament is that seven seats are reserved for special Māori voting lists. Under the system – established in 1867 – New Zealanders of Māori heritage are allowed to select whether they are registered on the general elector lists or the special Māori lists, and seven large electoral divisions are created on top of the 63 primary electoral divisions.

These Māori electorates – also filled by plurality voting – are almost always shared between the Labour party and the Māori Party.

In the past few weeks polling has seen a surge in support for the opposition Labour Party under new leader Jacinda Ardern, but the surge now appears to have eased back in the last week of the campaign.

Polling suggests that the incumbent National Party will win between 54 and 56 of the nominal 120 seats in the House, down from their previous holding of 60 seats.

Labour looks set to increase its seat numbers from 32 at the 2014 election to around 47 today.

Some of Labour’s gains will be at the expense of the Green Party, predicted to fall from 13 seats to 9 or 10.

The New Zealand First Party is expected to fall from 11 seats to between 7 and 9. But despite losing sets, New Zealand First will likely become the balance of power party.

The ACT party is still expected to win its one local seat, but earn no bonus seat allocation, while the Māori Party is picked to win just one of the seven separate divisional seats.

Since New Zealand First will be unwilling to favour a Labour alliance involving the Greens, the overall political result for forming a government is either a National-New Zealand First coalition, or else a minority National government generally requiring New Zealand First support.

At moments during the campaign the surge of support for Labour at the Green Party’s expense threatened to drop Green support below the crucial 5% threshold.

Such an outcome would have been a disaster for Labour as well as the Greens. Under MMP the worst possible electoral outcome for a minor party is polling 4.9%, effectively wasting the votes of all the voters concerned. But any major party that hoped to have allies in parliament from such a party is also severely affected when this happens.

Election results will be available from the NZ Electoral Commission and from media outlets.


Germany – Bundestag election Sunday September 24

image - german Reichstag building

The historic Reichstag building in Berlin (image: Wikipedia)

All opinion polls in Germany are consistently predicting that six parties will safely exceed the 5% national voter support threshold, up from four parties at the last elections in 2013.

Three-term Chancellor Angela Merkel’s Christian Democrat party (CDU-CSU*) is universally expected to be the largest party in the Bundestag, and there is little doubt that Merkel will be able to form some new coalition to remain as Chancellor.

(*The CSU is the centre-right party in the state of Bavaria, while in all other states the CDU is the major centre-right party. Despite some policy differences, for example on immigration matters, the two parties are essentially a unified entity for national political purposes.)

image - German Opinion Polls 2017 Election.png

The highly stable German opinion polls saw an abrupt surge of national support for the SPD (red) earlier in the year, but it has subsided; all four of the minor parties are consistently polling above the 5% threshold (graphic: Wikipedia)

The current German government is in fact a coalition of the two largest national parties, a regular occurrence when neither the CDU-CSU or the centre-left Social Democrat Party (SPD) wish to form coalitions with the more politically ‘extreme’ (by German standards) minor parties, der Linke and AfD.

In addition to the Greens and the Die Linke (Left) parties serving in the outgoing parliament, the new Bundestag is expected to see members from the traditionally centre-right Free Democrat Party (FDP) and the newer, nationalist and ‘populist right’ Alternative for Germany (AfD) party.

Since neither major party would consider coalition with the AfD, Merkel’s options will range between a coalition with the FDP, one with both the FDP and the Greens (known as a Jamaica coalition in Germany after the three party colours resembling the Jamaican flag), or a continuation of the grand coalition with the SPD. Which option the Chancellor negotiates will depend on the exact numbers in the Bundestag.

In 2013 the FDP polled a disastrous 4.8% of the national vote, falling out of the Bundestag for the first time in decades and depriving Chancellor Merkel of her preferred coalition partner. On Sunday all indications are that the FDP will safely return.

The CDU has performed well earlier in 2017 in länd (state) elections in Saarland, Schleswig-Holstein and North Rhine-Westphalia.

Results of Sunday’s Bundestag election should be available (in English) from the Federal Returning Officer.

One comment on “Double-header weekend for MMP voting system

  1. Pingback: Dutch, Germans, Kiwis edge towards governments | On Elections

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This entry was posted on September 23, 2017 by in Germany, MMP/British AMS, New Zealand.
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