MMP is the type of electoral system we have in New Zealand. It is the system by which members of parliament (MPs) are voted in by the people.
Under MMP you get two votes. With one you select a local electorate MP. With the second vote, you choose a political party.
About half the MPs in parliament are electorate MPs from 60 electorates. The other half are chosen from political party lists published before each election. Once the electorate seats are elected, list seats are allocated so that the overall number of seats each party gets reflects the percentage of the vote that party got.
How did we get MMP?
In 1986, a Royal Commission on Electoral Reform was set up to review the system, after several very unfair election results particularly in the 1980s and early 1990s and widespread dissatisfaction with the voting system. The Royal Commission recommended MMP was the best system for New Zealand.
In 1992, New Zealand voters chose MMP as their preferred alternative in a referendum. In 1993 in a binding referendum New Zealanders chose MMP to be our voting system, rejecting the earlier system, First Past the Past (FPP). The first MMP election was in 1996.
MMP: A Royal Commission chose MMP for New Zealand. Here's why. A short, clearly written booklet written by David Hay back in 1993 (revised in 2004) explaining how and why the Royal Commission on Electoral Reform chose MMP for New Zealand in 1986. Goes through the 10 criteria used to choose the best system, comparing First Past the Post to MMP.