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CPO-STV
CPO-STV, or the Comparison of Pairs of Outcomes by the Single Transferable Vote, is a ranked voting system designed to achieve proportional representation. It is a more sophisticated variant of the Single Transferable Vote (STV) system, designed to overcome some of that system's perceived shortcomings. It does this by incorporating some of the features of the Condorcet method, a voting system designed for single-winner elections, into STV. As in other forms of STV, in a CPO-STV election, more than one candidate is elected and voters must rank candidates in order of preference. As of February 2021, it has not been used for a public election. CPO-STV aims to overcome the problems of tactical voting in traditional forms of STV, where a candidate can be eliminated at an early stage in the process that might have gone on to be elected later had they been allowed to remain in the contest. CPO-STV works by an exhaustive comparison of the various possible outcomes of an election, in acc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Schulze STV
Schulze STV is a proposed multi-winner ranked voting system designed to achieve proportional representation. It was invented by Markus Schulze, who developed the Schulze method for resolving ties using a Condorcet method. Schulze STV is similar to CPO-STV in that it compares possible winning candidate pairs and selects the Condorcet winner. It is named in analogy to the single transferable vote (STV), but only shares its aim of proportional representation, and is otherwise based on unrelated principles. The system is based on Schulze's investigations into vote management and Freeriding (voting), free riding. When a voter prefers a popular candidate, there is an advantage to first choosing a candidate who is unlikely to win ("Woodall free riding") or omitting his preferred candidate from his rankings ("Hylland free riding"). Schulze STV is designed to be as resistant to free riding as possible, without giving up the Droop proportionality criterion. Example Each voter ranks candi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Single Transferable Vote
The single transferable vote (STV) or proportional-ranked choice voting (P-RCV) is a multi-winner electoral system in which each voter casts a single vote in the form of a ranked ballot. Voters have the option to rank candidates, and their vote may be transferred according to alternative preferences if their preferred candidate is eliminated or elected with surplus votes, so that their vote is used to elect someone they prefer over others in the running. STV aims to approach proportional representation based on votes cast in the district where it is used, so that each vote is worth about the same as another. STV is a family of multi-winner proportional representation electoral systems. The proportionality of its results and the proportion of votes actually used to elect someone are equivalent to those produced by proportional representation election systems based on lists. STV systems can be thought of as a variation on the largest remainders method that uses candidate-based so ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Condorcet Method
A Condorcet method (; ) is an election method that elects the candidate who wins a majority of the vote in every head-to-head election against each of the other candidates, whenever there is such a candidate. A candidate with this property, the ''pairwise champion'' or ''beats-all winner'', is formally called the ''Condorcet winner'' or ''Pairwise Majority Rule Winner'' (PMRW). The head-to-head elections need not be done separately; a voter's choice within any given pair can be determined from the ranking. Some elections may not yield a Condorcet winner because voter preferences may be cyclic—that is, it is possible that every candidate has an opponent that defeats them in a two-candidate contest. The possibility of such cyclic preferences is known as the Condorcet paradox. However, a smallest group of candidates that beat all candidates not in the group, known as the Smith set, always exists. The Smith set is guaranteed to have the Condorcet winner in it should one exist. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nicolaus Tideman
Thorwald Nicolaus Tideman (, not ; born August 11, 1943, in Chicago, Illinois) is a Georgist economist and professor at Virginia Tech. He received his Bachelor of Arts in economics and mathematics from Reed College in 1965 and his PhD in economics from the University of Chicago in 1969. Tideman was an assistant professor of economics at Harvard University from 1969 to 1973, during which time from 1970 to 1971 he was a Senior Staff Economist for the President's Council of Economic Advisors. Since 1973, he has been at Virginia Tech, with various visiting positions at Harvard Kennedy School (1979–1980), University of Buckingham (1985–1986), and the American Institute for Economic Research (1999–2000). Research Tideman's academic interests include taxation of land, voting theory, and political philosophy. Ranked Pairs In 1987, he devised the voting system called " ranked pairs" (or the "Tideman method" or simply "RP"), which is a type of Condorcet method. It selects a sin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ranked Voting Systems
Ranked voting is any voting system that uses voters' Ordinal utility, rankings of candidates to choose a single winner or multiple winners. More formally, a ranked vote system depends only on voters' total order, order of preference of the candidates. Ranked voting systems vary dramatically in how preferences are tabulated and counted, which gives them Comparison of voting rules, very different properties. In instant-runoff voting (IRV) and the single transferable vote system (STV), lower preferences are used as contingencies (back-up preferences) and are only applied when all higher-ranked preferences on a ballot have been eliminated or when the vote has been cast for a candidate who has been elected and surplus votes need to be transferred. Ranked votes of this type do not suffer the problem that a marked lower preference may be used against a voter's higher marked preference. Some ranked vote systems use ranks as weights; these systems are called positional voting. In the B ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Counting Single Transferable Votes
The single transferable vote (STV) is a proportional representation system and ranked voting rule that elects multiple winners. Under STV, an elector's vote is initially allocated to their first-ranked candidate. Candidates are elected (''winners'') if their vote tally exceeds the electoral quota''.'' Any surplus votes (those exceeding quota) are transferred from winners to the remaining candidates (''hopefuls'') according to the surplus ballots' next usable back-up preference. The system attempts to ensure factions are represented proportionally, without the need for official party lists, by having each winner elected with roughly the same number of votes. There are several variants of the Single Transferable Vote, each with different properties. Voting When using an STV ballot, the voter ranks candidates on the ballot. For example: Some, but not all single transferable vote systems require a preference to be expressed for every candidate, or for the voter to express at l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monotonicity Criterion
Electoral system criteria In social choice, the negative response, perversity, or additional support paradox is a pathological behavior of some voting rules where a candidate loses as a result of having too much support (or wins because of increased opposition). In other words, increasing (decreasing) a candidate's ranking or rating causes that candidate to lose (win), respectively. Electoral systems that do not exhibit perversity are sometimes said to satisfy the monotonicity criterion.D R Woodall"Monotonicity and Single-Seat Election Rules" '' Voting matters'', Issue 6, 1996 Perversity is often described by social choice theorists as an exceptionally severe kind of electoral pathology, as such rules can have "backwards" responses to voters' opinions, where popularity causes defeat while unpopularity leads to a win. Similar rules treat the well-being of some voters as "less than worthless". These issues have led to constitutional prohibitions on such systems as violating ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
First-past-the-post
First-past-the-post (FPTP)—also called choose-one, first-preference plurality (FPP), or simply plurality—is a single-winner voting rule. Voters mark one candidate as their favorite, or First-preference votes, first-preference, and the candidate with more first-preference votes than any other candidate (a Plurality (voting), ''plurality'') is elected, even if they do not have more than half of votes (a ''majority''). FPP has been used to elect part of the House of Commons of the United Kingdom, British House of Commons since the Middle Ages before spreading throughout the British Empire. Throughout the 20th century, many countries that previously used FPP have abandoned it in favor of other electoral systems, including the former British colonies of Australia and New Zealand. FPP is still De jure, officially used in the majority of U.S. state, US states for most elections. However, the combination of Partisan primary, partisan primaries and a two-party system in these jurisd ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sequential STV
In mathematics, a sequence is an enumerated collection of objects in which repetitions are allowed and order matters. Like a set, it contains members (also called ''elements'', or ''terms''). The number of elements (possibly infinite) is called the ''length'' of the sequence. Unlike a set, the same elements can appear multiple times at different positions in a sequence, and unlike a set, the order does matter. Formally, a sequence can be defined as a function from natural numbers (the positions of elements in the sequence) to the elements at each position. The notion of a sequence can be generalized to an indexed family, defined as a function from an ''arbitrary'' index set. For example, (M, A, R, Y) is a sequence of letters with the letter "M" first and "Y" last. This sequence differs from (A, R, M, Y). Also, the sequence (1, 1, 2, 3, 5, 8), which contains the number 1 at two different positions, is a valid sequence. Sequences can be ''finite'', as in these examples, or '' in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Droop Quota
In the study of Electoral system, electoral systems, the Droop quota (sometimes called the Eduard Hagenbach-Bischoff, Hagenbach-Bischoff, Britton, or Newland-Britton quota) is the Infimum, minimum number of votes a party or candidate needs to receive in a district to guarantee they will win at least one seat. Reprinted in ''Voting matters Issue 24'' (October 2007) pp. 7–46. The Droop quota is used to extend the concept of a majority to multiwinner elections, taking the place of the 50% bar in single-winner elections. Just as any candidate with more than half of all votes is guaranteed to be declared the winner in single-seat election, any candidate with more than a Droop quota's worth of votes is guaranteed to win a seat in a Multiwinner voting, multiwinner election. Besides establishing winners, the Droop quota is used to define the number of excess votes, i.e. votes not needed by a candidate who has been declared elected. In proportional electoral quota, quota-based syste ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Schulze Method
Articles with example pseudocode Debian Electoral systems Monotonic Condorcet methods Single-winner electoral systems The Schulze method (), also known as the beatpath method, is a single winner ranked-choice voting rule developed by Markus Schulze. The Schulze method is a Condorcet completion method, which means it will elect a majority-preferred candidate if one exists. In other words, if most people rank ''A'' above ''B'', ''A'' will defeat ''B'' (whenever this is possible). Schulze's method breaks cyclic ties by using indirect victories. The idea is that if Alice beats Bob, and Bob beats Charlie, then Alice (indirectly) beats Charlie; this kind of indirect win is called a "beatpath". For proportional representation, a single transferable vote (STV) variant known as Schulze STV also exists. The Schulze method is used by several organizations including Debian, Ubuntu, Gentoo, Pirate Party political parties and many others. It was also used by Wikimedia prior to th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
