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Mixed-member majoritarian representation (MMM) is type of amixed electoral system combiningwinner-take-all andproportional methods, where the disproportional results of the winner-take-all part are dominant over theproportional component. Mixed member majoritarian systems are therefore categorized undersemi-proportional representation, and are usually contrasted withmixed-memberproportional representation (MMP) which aims to provide proportional representation compensation ("top-up") seats.
The most common type of MMM system is thesupplementary member (SM) system (a form ofparallel voting), whereby representatives are voted into a chamber using at least two different systems independently of each other. Most commonly this combinesfirst-past-the-post (single member plurality) voting (FPTP/SMP) withparty-list proportional representation (list-PR). The system has been applied in the election of national parliaments as well as local governments in various places such asTaiwan,Lithuania,Russia andKazakhstan. While FPTP with list-PR is the most common pairing in parallel systems, any other combination is effectively possible. Therefore, not all parallel voting systems are mixed-member majoritarian (and not all MMM systems are strictly parallel -non-compensatory), however as most of them used in practice are, the terms are sometimes used interchangeably.
More unusual types of mixed-member majoritarian system are used inPakistan,Italy andHungary, and ade facto MMM system is used inSouth Korea.[a]
According to the academic typology of Massicotte & Blais (1999)[3], mixed-member majoritarian systems can come in the following forms:
Mixed-member majoritarian systems generally allow smaller parties that cannot win individual elections in awinner-take-all system to secure some representation in the legislature; however, unlike in a proportional system, they will have a substantially smaller delegation than their share of the total vote. Some articles argued that MMM does not lead to the degree ofpolitical fragmentation found in party systems under forms ofproportional representation with noelectoral threshold.[4] The two tiers interact through contamination effects to increase political fragmentation.[5]
A criticism of adding a proportional component to winner-take-all electoral systems is that the largest parties are more likely to rely on the support of smaller ones in order to form a government, compared to atwo-party system. However, smaller parties are still disadvantaged as the larger parties still predominate. In countries where there is one dominant party and a divided opposition, the proportional seats may be essential for allowing an effective opposition. Furthermore, the likelihood of no governing majority is dependent on many other factors, same as under first-past-the-post. In many democracies,coalition governments are not only the norm, but seen as desirable as the government is formed with wider (indirect) support of the electorate and via compromise between factions.
In parallel voting and other supplementary member systems, it is sometimes considered a negative, that there are two classes of representatives with one class beholden to their electorate seat, and the other concerned only with their party.
The major critique of MMM systems is that they have lower overallproportionality. Large parties can win very large majorities, disproportionate to their percentage vote. For example, in the2014 Hungarian election, the Fidesz/KDNP grouping won 133 of 199 Parliamentary seats with 44.87% of the overall vote.
Combined with a highelectoral threshold, small parties may still be shut out of representation entirely despite winning a substantial portion of the overall vote.[6] Mixed-member majoritarian representation incentivizesstrategic voting so thatvotes are not wasted. Voters of smaller parties might vote for a large party's constituency candidate, while voters of large parties may vote for allied smaller parties with their party list vote so as to help them over the threshold. An example of this being played out can be seen in the2014 Japanese election where the government's junior coalition partner,Komeito took only 1.5% in the local constituencies, but 13.7% on the PR list. Most of the Komeito votes came from the rulingLiberal Democratic Party[citation needed].
Mixed-member majoritarian (MMM) systems are often contrasted with mixed-Member proportional (MMP) systems. There are a unique set of advantages and disadvantages that apply to this specific comparison.
Under MMM a party that cangerrymander local districts can win more than its share of seats, so parallel systems need fair criteria to draw district boundaries. Normally, undermixed member proportional representation a gerrymander can help a local candidate, but it cannot raise a major party's share of seats, unless the compensatory link is effectively disentangled, for example using decoy lists and tactical voting.
InJapan, an electoral system based on a single-seat constituency system was introduced in 1994 to facilitate a change of government and prevent corruption. It was decided that a portion of the seats would be elected through a proportional representation system to accommodate minority parties. In Japan's political culture, however, this system further reinforced thedominant-party system, and except for a brief period between 2009 and 2012, the opposition parties faced theLDP as a minority force, aided by the proportional representation system. And subsequentlyThailand andRussia adopted a parallel system to provide incentives for greater party cohesiveness.[citation needed]
The party is sure to elect the candidates at the top of its list, guaranteeing safe seats for the leadership. By contrast, under the MMP system a party that does well in the local seats might not need or receive any compensatory list seats, so the leadership has to run in the local seats. On the other hand, because of the low reputation of lawmakers elected by proportional representation in Japan, party leaders of major parties are implicitly expected to be elected in their electoral districts. Although political parties can designate the order of the list, it is customary for the order to change according to the percentage of close defeats.
Mixed-member majoritarian systems support the creation of single-party majorities more often than mixed proportional member systems. This may be a positive or a negative depending on the view of the voter.
| Lower (or only) house of legislature chambers | Upper house of legislature chambers (where applicable) |
|---|---|
 |  |
| Other | |
First past the post (FPTP/SMP) + PR seats in proportion to FPTP seats MixedParty block voting / General ticket (PBV) + FPTP/SMP or FPTP/SMP + majority jackpot (supermixed) Mixed-member majoritarian /parallel voting (FPTP/SMP + party-list PR) Mixed-member majoritarian / parallel voting (TRS + party-list PR) Mixed-member majoritarian / parallel voting (BV or PBV + party-list PR) Mixed-member majoritarian with compensation /scorporo (FPTP/SMP + party-list PR) Majority bonus system (MBS) / Majority jackpot system (PBV + party-list PR) | Varies by federal states or constituencies No direct election No information |
Mixed-member majoritarian systems are primarily used in Asian and some of the European states.[7]
| Country | Body/region | Last election | Type | (Seats per constituency) | Electoral system | Total seats | Constituencies | Governmental system | Notes | |
|---|---|---|---|---|---|---|---|---|---|---|
 Andorra | General Council | 2019 | Parallel voting /superposition | 2 (local districts) / 14 (nationwide constituency) | Party block voting (PBV) in 14 local districts +List PR in a single nationwide constituency | 28 | 7 parishes, 1 nationwide constituency | Parliamentary system | ||
 Argentina | Legislature of Córdoba Province | 2019 | Parallel voting /superposition | 1 (local districts), 44 (provincewide constituency) | First-past-the-post (FPTP/SMP) andList PR | 70 | Departments | |||
| San Juan Province | 2019 | Parallel voting /superposition | 1 (local districts), 17 (provincewide constituency) | First-past-the-post (FPTP/SMP) andList PR | 36 | Departments | ||||
| Santa Cruz Province | 2019 | Parallel voting /superposition | 1 (local districts), 10 (provincewide constituency) | First-past-the-post (FPTP/SMP) andList PR | 24 | Municipalities | ||||
 Cameroon | National Assembly | 2020 | Hybrid/Supermixed (Conditional+coexistence) | 1–7 | First-past-the-post (FPTP/SMP) in single-member constituencies, party with over 50% of vote gets all seats in multi-member constituencies (party block voting), otherwise highest party gets half, rest distributed bylargest remainder (Hare quota) | 180 | electoral districts[citation needed] | |||
 Chad | National Assembly | 2011 | Hybrid/Supermixed (Conditional+coexistence) | First-past-the-post (FPTP/SMP) party with over 50% of vote gets all seats in multi-member constituencies (party block voting), otherwiseList PR (largest remainder, closed list) | 188 | electoral districts[citation needed] | ||||
 Democratic Republic of the Congo | National Assembly | 2018 | Coexistence | 1–18 | First-past-the-post (FPTP/SMP) in single-member districts andopen list in multi-member districts | 500 | electoral districts[citation needed] | |||
 Djibouti | National Assembly | 2018 | Majority jackpot (MBS) /fusion | 3–28 | 80% of seats (rounded to the nearest integer) in each constituency are awarded to the party receiving the most votes (party block voting), remaining seats are allocated proportionally to other parties receiving over 10% (closed list,D'Hondt method) | 65 | regions | Presidential system | ||
 Egypt | House of Representatives | 2020 | Parallel voting /superposition | 1 (local districts), 42–100 (list districts) | Two-round system (TRS) andparty block voting (PBV/General ticket)[citation needed] | 596 (568 directly elected + 28 appointed) | electoral districts[citation needed] | Semi-presidential system | ||
| Senate | Semi-presidential system | |||||||||
 Georgia | Parliament | 2020 | Parallel voting /superposition | 1 (local districts), 120 (national constituency) | Party-list PR (closed list) +First-past-the-post (FPTP/SMP) | 150 | electoral districts[citation needed] | Parliamentary system | Georgia's Parliament has 150 members, known as deputies, from which 120 members are proportional representatives and 30 are elected through a single-member district plurality system to represent their constituencies. Five parties and electoral blocs had representatives elected to the parliament in the 2008 elections: the United National Movement (governing party), The Joint Opposition, the Christian-Democrats, the Labour Party and Republican Party. Due to the large amount of support given to the ruling party the disproportionality of the 2008 election was very low (1.32 on theGallagher Index). | |
 Greece | Hellenic Parliament | 2019 | Majority bonus (MBS) /fusion | |||||||
 Guinea | National Assembly | 2020 | Parallel voting /superposition | 1 (local districts), 76 (national constituency) | Party-list PR (Hare quota) for 76 seats +First-past-the-post (FPTP/SMP) for 38 seats | 114 | single-member constituencies based on the 33prefectures and five communes ofConakry | |||
 Hungary | National Assembly (Országgyűlés) | 2022 | Hybrid/Supermixed (superposition+correction) | 1 (local districts), 93 (national constituency) | First-past-the-post (FPTP/SMP) for 106 seats + nationalList PR for 93 seats (combination ofparallel andpositive vote transfer) | 199 | local electoral districts within country/capital borders and a single nationwide constituency that includes non-resident with Hungarian citizenship as well | Parliamentary system | Hungary'sNational Assembly uses a system where the parallel voting component shares a pool of seats (93) with the compensatory vote transfer system and with the minority list seats with a reduced entry threshold. This means, the number of seats effectively assigned proportionally based on the parallel party list votes is unknown/unknowable before the election takes place.[8] Before the 2014, a different mixed system was used with a two-round system in single-member districts. | |
 Italy | Chamber of Deputies | 2018 | Superposition | 1 (local districts), 12 (Italians abroad constituency), ?-? (multi-member districts)[citation needed] | List PR +First-past-the-post (FPTP/SMP) - mixed single vote | 630 | electoral districts[citation needed] | Parliamentary system | Starting with the2018 election, both houses of theItalian parliament are elected using a system similar to parallel voting. 62.5% of the seats are assigned proportionally to party lists; party lists are also linked in coalitions supporting constituency candidates running for the remaining 37.5% of the available seats, who are elected by means of a first-past-the-post system. Electors have a single vote with two-fold proportional effects for a party list and its associated coalition candidate (split-ticket voting is not allowed). Between 1993 and 2005scorporo,parallel voting with modifications (negative vote transfer compensation) was used. | |
| Senate | 2018 | 1 (local districts), 6 (Italians abroad constituency), ?-? (multi-member districts)[citation needed] | List PR +First-past-the-post (FPTP/SMP) - mixed single vote | 315 | electoral districts[citation needed] | Parliamentary system | ||||
 Japan | House of Representatives | 2024 | Parallel voting /superposition | 1 (local districts), 11 (multi-member districts) | Party-list PR (open list) for 176 seats +First-past-the-post (FPTP/SMP) for 289 seats | 465 | electoral districts | Parliamentary system | ||
 Republic of Korea (South Korea) | National Assembly | 2024 | Parallel voting /superposition (de facto) | 1 (local districts), 46 (nationwide constituency) | First-past-the-post (FPTP/SMP) for 254 seats +List PR (closed list) for 46 seats (de facto)[1][2] | 300 | electoral districts[citation needed] | Presidential system | South Korea'sNational Assembly used mixed single voting from 1988 to 2001 and parallel voting from 2001 to 2019. Between 2019 and 2024, it nominally used a hybrid system of parallel voting and semi-mixed-member proportional, with both compensatory seats (30) and supplementary seats (17) but this system wasde facto nullified because of the usage ofdecoy lists by major parties. Since 2024, it has used semi-mixed-member proportional, with 46 compensatory seats but this has beende facto nullified again via decoy list usage by major parties.[9] | |
 Kazakhstan | Mäjilis | 2023 | Parallel voting /superposition | 1 (local districts), 69 (national constituency) | Party-list PR (closed list) for 69 seats +First-past-the-post (FPTP/SMP) for 29 seats | 98 | electoral districts[citation needed] | Semi-presidential system | TheKazakhstan Parliament has two chambers: the Assembly and the Senate. The Assembly (Mäjilis) has 98 seats, 29 of these are constituency seats and 69 list seats determined by proportional representation. | |
 Kyrgyzstan | Supreme Council | 2021 | Parallel voting /superposition | 1 (local districts), 54 (nationwide constituency) | Party-list PR (open list) for 54 seats +First-past-the-post (FPTP/SMP) for 36 seats | 90 | electoral districts[citation needed] | Presidential system | ||
 Lithuania | Seimas | 2020 | Parallel voting /superposition | 1 (local districts), 70 (nationwide constituency) | Two-round system (TRS) for 71 seats +List PR (Largest remainder) for 70 seats | 141 | electoral districts[citation needed] | Semi-presidential system | ||
 Madagascar | National Assembly | 2019 | Coexistence | 1–2 | First-past-the-post (FPTP/SMP) in 87 single-member districts,party-list PR (Closed list,highest averages method) in 32 two-member districts (64 seats inbinomial system) | 151 | electoral districts[citation needed] | Semi-presidential system | ||
 Mauritania | National Assembly | 2018 | Hybrid/Supermixed (coexistense+superposition) | 1–3 (local districts), 40 (nationwide constituency) | Two-round system (TRS) in single-member districts,two-round block voting (BV) in dual-member districts, andList PR (simple quota largest remainder; closed-list) in larger districts + twice 20 nationallyList PR (one set of 20 reserved for women) | 157 | electoral districts[citation needed] | Semi-presidential system | ||
 Mexico | Chamber of Deputies | 2024 | Parallel voting /superposition | 1 (local districts), 40 (multi-member districts) | First-past-the-post (FPTP/SMP) +Party-list PR (Largest remainder:Hare quota) | 500 | the local (single-member) districts are calledfederal electoral districts (with eachstate divided into at least two districts), and the remaining seats are assigned through rules ofproportional representation in 5 multi-state, 40-seatconstituencies. | Presidential system | Since 1996, a party cannot win more seats overall than 8% above its national result (i.e., to win 50% of the legislative seats, a party must win at least 42% of the vote nationwide). There are three exceptions to this rule: first, a party can only lose PR seats due to this rule (and no plurality seats); second, a party can never get more than 300 seats overall (even if it has more than 52% of the vote nationally); and third, a party can exceed this 8% rule if it wins the seats in the single-member districts. | |
| Senate of the Republic | 2024 | Superposition | 3 (local districts), 32 (multi-member districts) | Superposition using a single party vote:Limited (party) block voting locally (2 seats from each constituency to largest party, 1 to the second largest party) +Party-list PR nationwide | 128 | three-seatconstituencies corresponding to the nation's 31states and Mexico City (the former Federal District, which is the national capital) and a nationwide electoral district | Presidential system | |||
 Monaco | National Council | 2018 | Superposition | 24 (nationwide constituency) | Mixed-member majoritarian (MMM) using a single (panachage) ballot: Plurality block voting (BV) in single nationwide constituency for 16 seats;D'Hondt method (8 seats) | 24 | single nationwide constituency | Parliamentary system[citation needed] | ||
 Nepal | House of Representatives | 2022 | Parallel voting /superposition | 1 (local districts), 110 (multi-member districts) | First-past-the-post (FPTP/SMP) for 165 seats +Party-list PR (closed lists) for 110 seats | 275 | electoral districts and a single nationwide constituency | Parliamentary system | ||
 Panama | National Assembly | 2019 | Coexistence | First-past-the-post (FPTP/SMP) in single-member districts, Saripolo or Sartori method (Largest remainder, but remainders only for those with no seats) in multi-member districts | 71 | electoral districts[citation needed] | Presidential system | |||
 Pakistan | National Assembly | 2018 | Superposition | 1 (local districts), 60 (seats reserved for women), 10 (seats reserved for religious minorities) | First-past-the-post (FPTP/SMP) for 272 seats + 70 members appointed by parties proportional with seats already won | 342 | electoral districts[citation needed] | Parliamentary system | ||
 Philippines | House of Representatives | 2025 | Parallel voting /superposition | 1 (local districts), 63 (nationwide constituency) | First-past-the-post (FPTP/SMP) in single-member districts for 254 seats +List PR (closed lists; modifiedHare quota with 3-seat cap and no remainders) for 63 seats | 317 | electoral districts[citation needed] | Presidential system | The Philippines' electoral system for Congress is an exceptional case on this list. Political parties running for party-list seats are legally required to be completely separate from those running in constituency seats. Furthermore, political parties are capped at 3 seats (out of 61). As a result, the mixed-member system utilized in the Philippines is not representative at all of the share of the vote that "normal" political parties obtain (even amongst mixed-member majoritarian systems), let alone for those in full proportional representation systems. | |
 Russian Federation | State Duma | 2021 | Parallel voting /superposition | First-past-the-post (FPTP/SMP) for 225 seats +Party-list PR for 225 seats | 450 | electoral districts[citation needed] | Semi-presidential system | |||
 San Marino | Grand and General Council | 2019 | Majority jackpot /fusion | Majority jackpot system (35 seat jackpot) | ||||||
 Senegal | National Assembly | 2017 | Parallel voting /superposition | 1-? (local districts), 60 (nationwide constituency) | First-past-the-post (FPTP/SMP) in single-member districts andPlurality block voting (BV) in two-seat districts for 115 seats in total (including overseas) +List PR for 60 seats (largest remainder method) | 165 | single- or multi-member constituencies based on the 35departments, with an additional 15 elected by overseas voters and a single nationwide constituency | Presidential system | ||
 Seychelles | National Assembly | 2025 | Superposition | 1 (local districts), up to 10 (nationwide constituency) | First-past-the-post (FPTP/SMP) for 26 seats + up to a further ten are elected based on the percentage of votes received by each party; for each 10% of the total national vote received, a party gets one additional sea (List PR) for 8 seats | 34 (currently, may vary based on election results) | single member constituencies and a single nationwide constituency | Presidential system | ||
 South Ossetia | Parliament | 2024 | Parallel voting /superposition | 1 (local districts), up to 17 (nationwide constituency) | First-past-the-post (FPTP/SMP) for 17 seats +List PR for 17 seats | 34 | single member constituencies and a single nationwide constituency | |||
 Sudan | National Assembly | 2015 | Parallel voting /superposition | 1–26 (local districts), 128 (seats reserved for women), 85 (unreserved seats) | Plurality block voting (BV) in multi-member districts for 213 seats in total +List PR for 213 seats (?[citation needed] method,closed list) | 426 | 18states and a single nationwide constituency | |||
 Taiwan(Republic of China) | Legislative Yuan | 2024 | Parallel voting /superposition | 1 (local districts), 6 (seats reserved for indigenous), 34 (nationwide constituency) | First-past-the-post (FPTP/SMP) for 73 seats,single non-transferable vote for 6 seats reserved for indigenous +List PR for 34 seats | 113 | electoral districts[citation needed] and a single nationwide constituency | Semi-presidential system | ||
 Tajikistan | Assembly of Representatives | 2025 | Parallel voting /superposition | 1 (local districts), 22 (nationwide constituency) | Two-round system (TRS) for 41 seats +List PR for 22 seats | 63 | electoral districts[citation needed] and a single nationwide constituency | Presidential system | ||
 Tanzania | National Assembly | 2020 | Parallel voting /superposition | 1 (local districts), 75 (nationwide constituency) | First-past-the-post (FPTP/SMP) for 264 seats +List PR for 113 seats reserved for women[10] | 393 (377 directly elected) | ||||
 Thailand | House of Representatives | 2023 | Parallel voting /superposition | 1 (local districts), 400 (nationwide constituency) | First-past-the-post (FPTP/SMP) for 400 seats +List PR for 100 seats | 500 | electoral districts[citation needed] and a single nationwide constituency | Parliamentary system | The next election is scheduled to be held under parallel voting again, after one election (2019) held using a single vote MMP system | |
 Venezuela | National Assembly | 2025 | Parallel voting /superposition | First-past-the-post (FPTP/SMP) for 136 seats +list PR for 149 seats | 285 | electoral districts[citation needed] | Presidential system | |||
 Zimbabwe | National Assembly | 2023 | Superposition | 1 (local districts), 10 (proportional constituencies) | 210 seats byfirst-past-the-post (FPTP/SMP) in local districts + 60 seats reserved for women byParty-list PR + 10 seats reserved for youths byParty-list PR | 280 | electoral districts[citation needed] | Presidential system | Voters cast a single vote | |
Countries that replaced majoritarian representation before 1990 are not (yet) included.
| Country | Legislative body | Last use | Type of majoritarian system | Mixed majoritarian electoral system (old system) | Replaced by (new system) | Governmental system | Notes |
|---|---|---|---|---|---|---|---|
 Albania | Parallel voting | Albania used parallel voting in the 1996 and 1997 elections (before switching tomixed-member proportional representation from 2001 to2005).[11][12] | |||||
 Armenia | 2012 | Parallel voting | First-past-the-post (FPTP/SMP) andlist PR | Party-list proportional representation (List PR) | |||
 Azerbaijan | Parallel voting | Azerbaijan'sNational Assembly used an SM system in which 100 members were elected for five-year terms in single-seat constituencies and 25 were members were elected by proportional representation. Since 2020 it usesFPTP. | |||||
 Bulgaria | 1990, 2009 | Parallel voting | Party-list proportional representation (List PR) | ||||
 Croatia | 1995 | Parallel voting | Party-list proportional representation (List PR) | Used between 1993 and 2001 | |||
| Egypt | 2020 | ||||||
 Jordan | 2013 | Parallel voting | Party-list proportional representation (List PR) | ||||
 Moldova | 2018 | Parallel voting | Party-list proportional representation (List PR) | ||||
 North Macedonia | 1994[citation needed] | Parallel voting | Party-list proportional representation (List PR) | ||||
 Palestine | Legislative Council | 2006 | Parallel voting | Party-list proportional representation (List PR) | For thenext election (which is still yet to be held) the system was changed toparty-list proportional representation. | ||
 Timor-Leste (in former East Timor) | 2001 | Parallel voting | Party-list proportional representation (List PR) | ||||
 Tunisia | 2009 | Parallel voting | Party-list proportional representation (List PR) | ||||
 Ukraine | 2019 | Parallel voting | Party-list proportional representation (List PR) | According to the election law that became valid on 1 January 2020 the2023 Ukrainian parliamentary election will be held under a proportional scheme. | |||
| 2002 | Parallel voting | Party-list proportional representation (List PR) | 1994 election was held under a two-round system |
InNew Zealand, theRoyal Commission on the Electoral System reviewed the electoral system in 1985–86 and considered SM to be a possible replacement forplurality voting, which was in use at the time. They suggested the supplementary member system could be implemented in New Zealand with the following features: each elector would have 2 votes, 1 for a constituency candidate and the other for a party list; there would be a total of 120 seats, with 90 seats determined by votes in constituencies and the remaining 30 from party lists; a modifiedSainte-Laguë method would be used to allocate list seats proportionate to a party's total share of votes, a threshold of 5% was suggested before parties could be allocated seats.[13]
The commission came to the conclusion that SM would be unable to overcome the shortcomings of New Zealand's previous plurality electoral system (FPP). The total seats won by a party would likely remain out of proportion to its share of votes—there would be a “considerable imbalance between share of the votes and share of the total seats”—and would be unfair to minor parties (who struggle to win constituency seats).[13] In theindicative 1992 electoral referendum, SM was one of the four choices of alternative electoral system (alongsideMMP,AV andSTV), but came last with only 5.5 percent of the vote. By clear majority, a change to MMP was favoured, as recommended by the Royal Commission, and was subsequently adopted after the1993 electoral referendum.
Inanother referendum in 2011, 57.77% of voters elected to keep current the MMP system. Among the 42.23% that voted to change to another system, a plurality (46.66%) preferred a return to the pre-1994 plurality electoral system (also known asFirst-past-the-post, FPTP). Supplementary member was the second-most popular choice, with 24.14% of the vote.
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