|Part of the Politics series|
Semi-proportional representation characterizes multi-winner electoral systems which allow representation of minorities, but are not intended to reflect the strength of the competing political forces in close proportion to the votes they receive. Semi-proportional voting systems can be regarded as compromises between forms of proportional representation such as party-list PR, and plurality/majoritarian systems such as first-past-the-post voting. Examples of semi-proportional systems include the single non-transferable vote, limited voting, and parallel voting.
Most proportional representation systems do not yield precisely proportional outcomes due to the use of election thresholds, small electoral regions, or other implementation details that vary from one elected body to another. This article deals primarily with systems inherently designed to produce moderately proportional election results.
The choice to use a semi-proportional electoral system may be a deliberate attempt to find a balance between single-party rule and proportional representation. Semi-proportional systems can allow for fairer representation of those parties that have difficulty gaining even a single seat while retaining the possibility of one party gaining an overall majority of seats even if it receives less than a majority of the votes; they can ensure that the two or three largest parties all have their due share of seats or more while not producing representation for the smallest parties.
Because there are many measures of proportionality, and because there is no objective threshold, opinions may differ on what constitutes a semi-proportional system as opposed to a non-proportional one or a fully proportional system.
Election systems in which a party can achieve its due share of seats (proportionality) only by coordinating itsr voters are usually considered to be semi-proportional. They are not non-proportional or majoritarian, since in the perfect case the outcome will be proportional, but they are not proportional either, since such a perfect case requires a very high degree of coordination. Such systems include the single non-transferable vote and limited voting, the latter of which becomes less proportional the more votes each voter has. (under limited voting, coordination of voters is often secured by limiting the size of the party slate to the number of votes each voter has.) The cumulative voting also allows minority representation, but only by concentrating votes on the number of candidates that a minor party thinks it can elect, often just one.
This group of non-partisan systems is, at least technically, non-partisan. Certainly, a group of candidates can coordinate their campaigns, and politically present themselves as party members, but there is no obligation for electors to respect those party links, and forms of panachage are usually possible.
Single transferable vote
Main article: Single transferable vote
Some consider STV to be a semi-proportional system. Others describe it as a proportional system. The degree of proportionality of the results in a district (and when combined with other district results, the proportionality of results across a country) depends on the number of seats elected in the district. In the 2011 Irish general election, Fine Gael came nine seats (4.8%) short of an overall majority with just 36.1% of the first preference votes. Ireland uses a range of sizes of districts, three to five. The election results were exceptional -- Fine Gael benefited from transfers from those who did not rank them first, from voters whose back-up preferences allowed their vote to cross party lines.
Under STV a party can win an overall majority with significantly fewer than 50% of the first preference votes. This usually happens when a party gains many vote transfers from those who did not give their first preference to that party. Ireland lacks any arbitrary nationwide election threshold, which can also produce dis-proportional results. In other countries where an electoral threshold is used, some parties are arbitrarily blocked off from taking seats. Thus even with Ireland's somewhat small 3 to 5 seat District Magnitude, the level of proportionality in Ireland does not veer too far from PR countries with electoral thresholds.
Other forms of semi-proportional representation are based on, or at least use, party lists to work. Looking to the electoral systems effectively in use around the world, there are three general methods to reinforce the majoritarian principle of representation (but not necessarily majoritarianism or majority rule, see electoral inversion and plurality) starting from basic PR mechanisms: parallel voting, the majority bonus system (MBS), and extremely reduced constituency magnitude.
In additional member systems (AMS) where the additional members are not sufficient to balance the disproportionality of the original system can produce less than proportional results, especially in the National Assembly for Wales where only 33.3% of members are compensatory. The electoral system commonly referred to in Britain as the "additional member system" is also used for the Scottish Parliament, and the London Assembly, with generally proportional results. Similarly, in vote transfer based mixed single vote systems the number of compensatory seats may be too low (or too high) to achieve proportionality, such a system is used in Hungary in local elections The "scorporo" system used for the Parliament of Italy from 1993 to 2005 and the electoral system for the National Assembly of Hungary since 1990 are also special cases, based on parallel voting, but also including compensatory mechanisms – which however are insufficient for providing proportional results.
A majority bonus system takes an otherwise proportional system based on multi-member constituencies, and introduces disproportionality by granting additional seats to the first party or alliance. Majority bonuses help produce landslide victories similar to those which occur in elections under plurality systems. The majority bonus system was first introduced by Benito Mussolini to win the election of 1924, then it was later used in Italy again, with additional democratic limits, and then again expanded in some neighboring countries like San Marino, Greece and France.
The simplest mechanism to reinforce major parties in PR system is a severely reduced constituency magnitude, so to reduce the possibility for minor national parties to gain seats. If the Spanish electoral system is still considered a form of proportional representation, the binomial voting system used in Chile effectively establishes by law a two-party rule over the country.
The last main group usually considered semi-proportional consists of parallel voting models. The system used for the Chamber of Deputies of Mexico since 1996 is considered a parallel voting system, modified by a list-seat ceiling (8%) for over-representation of parties.
|Country||Legislative body||Latest election (year)||Type of majoritarian system||(Seats per
|Electoral system||Total seats||Constituencies||Governmental system||Notes|
|Andorra||General Council||2018||Mixed-member majoritarian||2 (local districts) / 14 (nationwide constituency)||Parallel voting / superposition (MMM):||28||7 parishes,
1 nationwide constituency
|Democratic Republic of the Congo||National Assembly||2018||Mixed-member majoritarian||1–17||Coexistence mixed majoritarian (MMM):||500||Electoral districts|
|Djibouti||National Assembly||2018||Mixed-member majoritarian||3–28||Fusion / majority jackpot (MBS):
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)
|France||French Polynesia Assembly||2018||Mixed-member majoritarian||4–17||Two-round majority bonus system (MBS) in multi-member constituencies||57||Electoral districts|
|Georgia||Parliament||2020||Mixed-member majoritarian||1 (local districts),
120 (national constituency)
|Parallel voting / superposition (MMM):||150||Electoral districts||Parliamentary system|
|Greece||Mixed-member majoritarian||Majority bonus system (MBS)|
|Guinea||National Assembly||2020||Mixed-member majoritarian||1 (local districts),
76 (national constituency)
|Parallel voting / superposition (MMM):||114||Single-member constituencies based on the 33 prefectures and five communes of Conakry|
|Hungary||National Assembly (Országgyűlés)||2018||Mixed-member majoritarian||1 (local districts), 93 (national constituency)||Supermixed / Mixed-member majoritarian (MMM):||199||Local electoral districts within country/capital borders and a single nationwide constituency that includes non-resident with Hungarian citizenship as well||Parliamentary system||Before the 2014, a different mixed system was used with a two-round system in single-member districts|
|Iraq||Single non-transferable vote (SNTV)|
|Italy||Chamber of Deputies||2018||Mixed-member majoritarian||1 (local districts), 12 (Italians abroad constituency), ?-? (multi-member districts)||Superposition / Mixed-member majoritarian (MMM) using a single vote||630||Electoral districts||Parliamentary system|
|Senate||2018||Mixed-member majoritarian||1 (local districts), 6 (Italians abroad constituency), ?-? (multi-member districts)||Superposition / Mixed-member majoritarian (MMM) using a single vote||315||Electoral districts||Parliamentary system|
|Republic of Korea (South Korea)||National Assembly||2020||Mixed-member majoritarian||1 (local districts), 17 supplementary seats (parallel voting), 30 additional seats (AMS),||Supermixed / Mixed-member majoritarian (MMM):||300||Electoral districts||Presidential system|
|Kuwait||Single non-transferable vote (SNTV)|
|Kyrgyzstan||Supreme Council||2021||Mixed-member majoritarian||1 (local districts), 54 (nationwide constituency)||Parallel voting / superposition (MMM):||90||Electoral districts||Presidential system|
|Lithuania||Seimas||2020||Mixed-member majoritarian||1 (local districts), 70 (nationwide constituency)||Parallel voting / superposition (MMM):||141||Electoral districts||Semi-presidential system|
|Madagascar||National Assembly||2019||Mixed-member majoritarian||1–2||Coexistence: 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 in binomial system)||151||Electoral districts||Semi-presidential system|
|Mauritania||National Assembly||2018||Mixed-member majoritarian||1–3 (local districts), 40 (nationwide constituency)||Coexistence+superposition (parallel) supermixed/hybrid:
Two-round system (TRS) in single-member districts, two-round block voting (BV) in dual-member districts, and List PR (simple quota largest remainder; closed-list) in larger districts + twice 20 nationally List PR (one set of 20 reserved for women)
|157||Electoral districts||Semi-presidential system|
|Monaco||National Council||2018||Mixed-member majoritarian||24 (nationwide constituency)||Superposition / Mixed-member majoritarian (MMM) using a single (panachage) ballot:||24||Single nationwide constituency||Parliamentary system|
|Palestine||Legislative Council||2006||Mixed-member majoritarian||1–9 (local districts), 66 (nationwide constituency)||Parallel voting / superposition (MMM):||132||Local electoral districts and a single nationwide constituency||Semi-presidential system||In the 1996 elections, 88 PLC members were chosen from several multi-member constituencies via block voting|
|Panama||National Assembly||2019||Mixed-member majoritarian||Coexistence mixed majoritarian (MMM):||71||Electoral districts||Presidential system|
|Philippines||House of Representatives||2019||Mixed-member majoritarian||1 (local districts), 61 (nationwide constituency)||Parallel voting / superposition (MMM):||304||Electoral districts||Presidential system|
|Russian Federation||State Duma||2021||Mixed-member majoritarian||||Parallel voting / superposition (MMM):||450||Electoral districts||Semi-presidential system|
|San Marino||Majority bonus system (MBS)|
|Senegal||2017||Mixed-member majoritarian||Parallel||165||Presidential system|
|Seychelles||2020||Mixed-member majoritarian||Parallel||35||Presidential system|
|Singapore||2020||Mixed-member majoritarian||First-past-the-post (FPTP/SMP) and party block voting (PBV)||104 (93 directly elected)|
|Switzerland||Council of States
|2||Single non-transferable vote (SNTV)||46|
|Thailand||2019 (using MMP)||Mixed-member majoritarian||Parallel||500||The next election is scheduled to be held under parallel voting again, after one election (2019) held using a single vote MMP system|
|British Overseas Territories (United Kingdom)||Gibraltar||Limited voting (LV)|
|Pitcairn Islands||Single non-transferable vote (SNTV)|
|Vanuatu||Single non-transferable vote (SNTV)|
|Venezuela||National Assembly||2020||Mixed-member majoritarian||Parallel voting (MMM):||280 (277 directly elected)||Electoral districts||Presidential system|
|Zimbabwe||National Assembly||2018||Mixed-member majoritarian||1 (local districts),
10 (proportional constituencies)
|Mixed-member majoritarian (MMM):
210 seats by first-past-the-post (FPTP/SMP) in local districts
60 seats reserved for women by list PR
|270||Electoral districts||Presidential system||Voters cast a single vote|