Proportional representation (PR) refers to any type of electoral system under which subgroups of an electorate are reflected proportionately in the elected body. The concept applies mainly to political divisions among voters. The essence of such systems is that all votes cast – or almost all votes cast – contribute to the result and are effectively used to help elect someone. Under other election systems, a bare plurality or a scant majority are all that are used to elect candidates. Further, a PR system is one that produces mixed and balanced representation, reflecting how votes are cast.
The additional member system (AMS) or is a two vote seat-linkage-based mixed electoral system used in the United Kingdom where most representatives are elected in single-member districts (SMDs), and a fixed number of other "additional members" are elected from a closed list to make the seat distribution in the chamber more proportional to the votes cast for party lists. It is distinct from using parallel voting for the list seats in that the "additional member" seats are awarded to parties taking into account seats won in SMDs - these are ignored under parallel voting.
Mixed-member proportional representation is a type of representation provided by some mixed electoral systems which combine local winner-take-all elections with a compensatory tier with party lists, in a way that produces proportional representation overall. Like proportional representation, MMP is not a single system, but a principle and goal of several similar systems. Some systems designed to achieve proportionality are still called mixed-member proportional, even if they generally fall short of full proportionality. In this case, they provide semi-proportional representation.
In political science, parallelvoting or superposition refers to the use of two or more electoral systems to elect different members of a legislature. More precisely, an electoral system is a superposition if it is a mixture of at least two tiers, which do not interact with each other in any way; one part of a legislature is elected using one method, while another part is elected using a different method, with all voters participating in both. Thus, the final results can be found by calculating the results for each system separately based on the votes alone, then adding them together. A system is called fusion or majority bonus, another independent mixture of two system but without two tiers. Superposition is also not the same as "coexistence", which when different districts in the same election use different systems. Superposition, fusion and coexistence are distinct from dependent mixed electoral systems like compensatory (corrective) and conditional systems.
Bolivia elects on national level a head of state – the president – and a legislature. The president and the vice-president are elected for a five-year term by the people. The National Congress has two chambers. The Chamber of Deputies has 130 members, elected for a five-year term using a two vote seat linkage compensatory system and in the case of seven indigenous seats by usos y costumbres. The Chamber of Senators has 36 members: each of the country's nine departments returns four senators allocated proportionally.
The majority bonus system (MBS), sometimes referred to as the reinforced proportionality electoral system is a semi-proportional method of election multiple representatives. The majority bonus is typically classified a mixed electoral system, as it integrates both the proportionality and winner-take-all principles to provide mixed-member majoritarian representation. An academic term for such a hybrid system is fusion, which means an independent combination of two systems in which the two formulas are mixed within the same district (the district in question may be a single, nationwide constituency). This makes it distinct from other mixed systems such as parallel voting (superposition) and coexistence. A majority bonus may also be one of the properties of a supermixed system.
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 are generally used as a compromise between complex and expensive but more-proportional systems and simple winner-take-all systems. Examples of semi-proportional systems include the single non-transferable vote, limited voting, and parallel voting.
An electoral or voting system is a set of rules used to determine the results of an election. Electoral systems are used in politics to elect governments, while non-political elections may take place in business, non-profit organisations and informal organisations. These rules govern all aspects of the voting process: when elections occur, who is allowed to vote, who can stand as a candidate, how ballots are marked and cast, how the ballots are counted, how votes translate into the election outcome, limits on campaign spending, and other factors that can affect the result. Political electoral systems are defined by constitutions and electoral laws, are typically conducted by election commissions, and can use multiple types of elections for different offices.
A winner-take-all electoral system is one where a voting bloc can win all seats in a legislature or electoral district, denying representation to any political minorities. Such systems are used in many major democracies. Such systems are sometimes called "majoritarian representation", though this term is a misnomer, as most such systems do not always elect majority preferred candidates and do not always produce winners who received majority of votes cast in the district, and they allow parties to take a majority of seats in the chamber with just a minority of the vote.
The Italian electoral law of 2015, also known as Italicum, was an Italian electoral law passed in 2015. The law, which came into force on 1 July 2016, regulated only the election of the Chamber of Deputies, replacing the Italian electoral law of 2005, which had been ruled partly unconstitutional by the Constitutional Court of Italy in December 2013. It provided for a two-round system based on party-list proportional representation, including a majority bonus and a 3% election threshold. Candidates would have run in 100 multi-member constituencies using open lists. The largest party which won over 40% of the vote would automatically win a majority of seats; if no party won 40% of seats, a second round of voting would be held between the two largest parties, with the winner of the second round winning a majority of seats. The name "Italicum" was coined in 2014 by Democratic Party secretary and later Prime Minister of Italy, Matteo Renzi, who was one of the legislation's main proponent.
A mixed electoral system is one that uses different electoral systems to elect different seats in a legislature. Most often, this involves a winner-take-all component combined with a proportional component. The results of the combination may be mixed-member proportional (MMP), where the overall results of the elections are proportional, or mixed-member majoritarian, in which case the overall results are semi-proportional, retaining disproportionalities from the majoritarian component. Systems that mix more than two components are sometimes called supermixed.
The Italian electoral law of 2017, colloquially known by the nickname Rosatellum after Ettore Rosato, the Democratic Party (PD) leader in the Chamber of Deputies who first proposed the new law, is a parallel voting system, which acts as a mixed electoral system, with 37% of seats allocated using a first-past-the-post electoral system and 63% using a proportional method, with one round of voting. The Chamber and Senate of the Republic did not differ in the way they allocated the proportional seats, both using the largest remainder method of allocating seats.
Ettore Rosato is an Italian politician, member of the Chamber of Deputies, and formerly leader of the Democratic Party in the Chamber.
The Legislature XIV of Italy started on 30 May 2001 and ended on 27 April 2006. Its composition resulted from the general election of 13 May 2001. The election was called by President Ciampi, after he dissolved the houses of Parliament on 8 March 2001. The legislature ended after its natural course of five years, soon after the houses were dissolved again by Ciampi on 11 February 2006.
A mixed single vote (MSV) is a type of ballot in mixed-member electoral systems, where voters cast a single vote in an election, which used both for electing a local candidate and as a vote for a party affiliated with that candidate according to the rules of the electoral system. Unlike most mixed proportional and mixed majoritarian systems where voters cast two votes, split-ticket voting is not possible under MSV. This significantly reduces the possibility of manipulating compensatory mixed systems, at the price of reducing voter choice. An alternative based on the mixed single vote that still allows for indicating different preferences on different levels is the mixed ballot, which functions as a preferential (mixed) single vote.
The mixed ballot transferable vote (MBTV) refers to a type of vote linkage-based mixed-member electoral system where a group of members are elected on local (lower) tier, for example in single-member districts (SMDs). Other members are elected on a compensatory national (upper) tier from a list and voters cast a single ballot where they may indicate their preferences separately.
Mixed-member majoritarian representation (MMM) is type of a mixed electoral system combining winner-take-all and proportional methods, where the disproportional results of the winner-take-all part are dominant over the proportional component. Mixed member majoritarian systems are therefore categorized under semi-proportional representation, and are usually contrasted with mixed-member proportional representation (MMP) which aims to provide proportional representation compensation ("top-up") seats.
The next Italian general election will occur no later than 22 December 2027, although it may be called earlier as a snap election.
Compensation or correction is an optional mechanism of electoral systems, which corrects the results of one part of the system based on some criterion to achieve a certain result, usually to make it more proportional. There are in general two forms of compensation: vote linkage and seat linkage.
The vote linkage or (multi-tier) vote transfer system is type of compensatory mixed electoral system, where votes may be transferred across multiple tiers of an electoral system, in order to avoid wasted votes - in contrast to the more common seat linkage compensatory system. It often presupposes and is related to the concept of the mixed single vote, which means that the same vote can be use in multiple tiers of an electoral system and that a vote for a local candidate may automatically count as a vote for the candidate's party or the other way around. Voters usually cast their single vote for a local candidate in a single-member district (SMD) and then all the wasted votes from this lower tier are added to distribute seats between upper tier candidates, typically national party lists.
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