Mixed electoral system

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A mixed electoral system or mixed-member electoral system combines methods of majoritarian and proportional representation (PR).^[1][2][3] The majoritarian component is usually first-past-the-post voting (FPTP/SMP),^[4] whereas the proportional component is most often based on party-list PR. The results of the combination may be mixed-member proportional (MMP), where the overall results of the elections are proportional,^[2] or mixed-member majoritarian, in which case the overall results are semi-proportional, retaining disproportionalities from the majoritarian component.

Mixed-member systems also often combine local representation^[5] (most often single-member constituencies) with regional or national (multi-member constituencies) representation, having multiple tiers.^[6] This also means voters often elect different types of representatives who might have different types constituencies. Some representatives may be elected by personal elections where voters vote for candidates, and some by list elections where voter vote primarily for electoral lists of parties.

In most mixed systems, every voter can influence both the district-based and PR aspects of an election,^[7] such as under parallel voting; in others, the voter casts just one vote (mixed single vote), which is used to contribute to both a personal (usually district) election and to the filling of seats through list system.^[8] Most mixed systems have all the voters contributing to the election of both groups of members.