The
Additional Member System (AMS) is a branch of
voting systemA voting system or voting theory, allows voters to choose between options, often in an election where candidates are selected for public office. Voting can be also used to award prizes, to select between different plans of action, or by a computer program to find a solution to a problem...
s in which some representatives are elected from geographic constituencies and others are elected under
proportional representationProportional representation , sometimes referred to as full representation, is a category of electoral formula aimed at securing a close match between the percentage of votes that groups of candidates obtain in elections and the percentage of seats they receive...
from a wider area, usually by
party listsParty-list proportional representation systems are a family of voting systems emphasizing proportional representation in elections returning multiple candidates...
. Voters have two votes, one for the party and the second for the candidate in a constituency. The constituency representatives are generally elected under the first-past-the-post voting system. The party representatives are elected by a party vote, where the electors vote for a political party, and usually not directly for an individual.
The
Additional Member System (AMS) is a branch of
voting systemA voting system or voting theory, allows voters to choose between options, often in an election where candidates are selected for public office. Voting can be also used to award prizes, to select between different plans of action, or by a computer program to find a solution to a problem...
s in which some representatives are elected from geographic constituencies and others are elected under
proportional representationProportional representation , sometimes referred to as full representation, is a category of electoral formula aimed at securing a close match between the percentage of votes that groups of candidates obtain in elections and the percentage of seats they receive...
from a wider area, usually by
party listsParty-list proportional representation systems are a family of voting systems emphasizing proportional representation in elections returning multiple candidates...
. Voters have two votes, one for the party and the second for the candidate in a constituency. The constituency representatives are generally elected under the first-past-the-post voting system. The party representatives are elected by a party vote, where the electors vote for a political party, and usually not directly for an individual. The particular individuals selected come from lists drawn up by the political parties before the election, at a national or regional level.
Variations of the AMS have different ways of determining how many party representatives each party is entitled to. The main difference between systems is whether the constituency representatives are counted when party representatives are allocated.
- Under the Mixed Member Proportional
Mixed member proportional representation, also termed mixed-member proportional voting and commonly abbreviated to MMP, is an 'additional member' voting system used to elect representatives to numerous legislatures around the world...
(MMP) or Top-Up (compensatory) system, the aim is either for the party's total number of representatives, including constituency representatives, to be proportional to its percentage of the party vote, or for the allocation of additional party seats to offset some or all of the disproportionate result in the constituencies. The party vote largely determines the number of representatives the party has in the assembly.
- Under the Parallel Voting
Parallel voting describes a mixed voting system where voters in effect participate in two separate elections using different systems, and where the results in one election have little or no impact on the results of the other...
or Supplementary Member (SUP or SM) system, the party seats are allocated proportionally within themselves, without consideration of any constituency seats the party may have won.
- Under the French proportional system designed to produce a strong majority, half the seats are given proportionally between party lists and the other half given to the list with a plurality, thus ensuring that a single list wins well over half the seats.
Parallel Voting is among the most common variation among
voting systems of the worldThis table deals with voting to select candidates for office, not for the passing of legislation.- Voting systems by country :-Key:Seats per district : Most elections are split into a number of districts . In some elections, there is one person elected per district...
. Small parties will generally win more seats under
MMP than
SUP unless there is a threshold of exclusion, such as the 5% or 3 constituencies threshold in Germany, or the 5% or 1 constituency seat threshold in New Zealand.
Criticisms
Since smaller parties are likely, in compensatory systems, to win a larger number of proportional seats, such additional member systems hand additional political power to the leaders of these parties at the expense of regional directly elected representatives, unless the additional members are elected on an open regional list as in Bavaria or a closed regional list as in Scotland. With closed lists, "Party List" candidates may become puppets for the party leadership, or may add diversity to the party's elected members. The largest party in an election is likely to win a smaller number of proportional seats, so that governing parties are less likely to have such figureheads. However, the majority party may lose diversity, unless the members elected from the party list when it was in opposition then win local seats when the party gains enough support to form the government.
In Parallel systems even the largest party will elect members from the party list, so the top list positions are guaranteed seats. This system is found in emerging democracies like post-communist Russia, where new national parties were evolving, and the voting system was intended to foster them, while allowing local independent members to win local seats, many of whom then joined the winning party. It retains the plurality principle but has another paper to allow voting for a party rather than a candidate.
See also
- Leveling seat
Leveling seats are a mechanism employed in Norwegian elections to the national legislature, the Storting, and in Swedish elections to national and regional assemblies, to ensure proportional representation both by county and political party...
- List of democracy and elections-related topics
- Voting system
A voting system or voting theory, allows voters to choose between options, often in an election where candidates are selected for public office. Voting can be also used to award prizes, to select between different plans of action, or by a computer program to find a solution to a problem...