MMP is classified as a proportional representation voting system. This is because the overall result closely mirrors the party vote.
The share of seats a political party wins in Parliament is about the same as its share of the party vote. This applies both to big parties and to small parties if they qualify for a share of the seats in Parliament by achieving one of the two thresholds.
The main features of MMP are illustrated in the results of the 2005 and 2008 Parliamentary elections in New Zealand.
In 2005, all the parties that qualified for seats in Parliament won a share of the seats that was about the same as their share of the party votes. For example, the Labour Party won 41.1% of the party votes and 41.3% of the seats in Parliament. Likewise, the New Zealand First party won 5.7% of the party votes in 2005 and 5.8% of the seats in Parliament.
In 2008, many of the parties represented in Parliament had a slightly higher share of the seats than their share of the nation-wide party votes. This was partly because the party that won the fourth-highest share of the party votes (New Zealand First) failed to reach either the 5% party-vote threshold or the one-seat threshold and thus won no seats in Parliament. In 2008 the Green Party did not win any electorates seats. However, because the Green Party (with 6.7% of the party votes) had cleared the 5% party-vote threshold, it was entitled to 9 List seats – 7.4% of all the seats in Parliament.
What type of government is usually formed?
Under MMP, coalitions or agreements between political parties are usually needed before Governments can be formed.
For example, after the 2005 election in New Zealand, the largest party in Parliament – Labour – formed a government after signing a coalition agreement with the Progressive Party and signing "confidence and supply" agreements with the New Zealand First and United Future parties. Similarly, after the 2008 election the largest party in Parliament – National – formed a government after negotiating "confidence and supply" agreements with the ACT, Māori and United Future parties.