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Participation Criterion
The participation criterion is a voting system criterion that says candidates should never lose an election as a result of receiving too many votes in support. More formally, it says that adding more voters who prefer ''Alice'' to ''Bob'' should not cause ''Alice'' to lose the election to ''Bob''. Voting systems that fail the participation criterion exhibit the no-show paradox, where a voter is effectively disenfranchised by the electoral system because turning out to vote could make the result worse for them; such voters are sometimes referred to as having negative vote weights, particularly in the context of German constitutional law, where courts have ruled such a possibility violates the principle of one man, one vote. Positional methods and score voting satisfy the participation criterion. All deterministic voting rules that satisfy pairwise majority-rule can fail in situations involving four-way cyclic ties, though such scenarios are empirically rare, and the random ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Positional Voting
Positional voting is a ranked voting electoral system in which the options or candidates receive points based on their rank position on each ballot and the one with the most points overall wins. The lower-ranked preference in any adjacent pair is generally of less value than the higher-ranked one. Although it may sometimes be weighted the same, it is never worth more. A valid progression of points or weightings may be chosen at will (Voting at the Eurovision Song Contest, Eurovision Song Contest) or it may form a mathematical sequence such as an arithmetic progression (Borda count), a geometric one (Positional notation, positional number system) or a harmonic one (Borda count#Dowdall system (Nauru), Nauru/Dowdall method). The set of weightings employed in an election heavily influences the rank ordering of the candidates. The steeper the initial decline in preference values with descending rank, the more polarised and less consensual the positional voting system becomes. Position ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Comparison Of Electoral Systems
This article discusses the methods and results of comparing different electoral system, electoral systems. There are two broad methods to compare voting systems: # Metrics of voter satisfaction, either through simulation or survey. # #Logical criteria for single-winner elections, Adherence to logical criteria. Evaluation by metrics Models of the electoral process Voting methods can be evaluated by measuring their accuracy under random simulated elections aiming to be faithful to the properties of elections in real life. The first such evaluation was conducted by Chamberlin and Cohen in 1978, who measured the frequency with which certain non-Condorcet systems elected Condorcet winners. Condorcet jury model The Marquis de Condorcet viewed elections as analogous to jury votes where each member expresses an independent judgement on the quality of candidates. Candidates differ in terms of their objective merit, but voters have imperfect information about the relative merits of the cand ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ranked-choice Voting In The United States
Ranked-choice voting (RCV) can refer to one of several ranked voting methods used in some cities and states in the United States. The term is not strictly defined, but most often refers to instant-runoff voting (IRV) or single transferable vote (STV), the main difference being whether only one winner or multiple winners are elected. At the federal and state level, instant runoff voting is used for congressional and presidential elections in Maine; state, congressional, and presidential general elections in Alaska; and special election, special congressional elections in Hawaii. Starting in 2025, it will also be used for all elections in the District of Columbia. Single transferable voting, only possible in multi-winner contests, is not currently used in state or congressional elections. It is used to elect city councillors in Portland, Oregon, Cambridge, Mass., and several other cities. As of April 2025, RCV is used for local elections in 47 US cities including Salt Lake City and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Largest Remainder Method
Party-list proportional representation Apportionment methods The quota or divide-and-rank methods make up a category of apportionment rules, i.e. algorithms for allocating seats in a legislative body among multiple groups (e.g. parties or federal states). The quota methods begin by calculating an entitlement (basic number of seats) for each party, by dividing their vote totals by an electoral quota (a fixed number of votes needed to win a seat, as a unit). Then, leftover seats, if any are allocated by rounding up the apportionment for some parties. These rules are typically contrasted with the more popular highest averages methods (also called divisor methods). By far the most common quota method are the largest remainders or quota-shift methods, which assign any leftover seats to the "plurality" winners (the parties with the largest remainders, i.e. most leftover votes). When using the Hare quota, this rule is called Hamilton's method, and is the third-most common ap ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proportional Representation
Proportional representation (PR) refers to any electoral system under which subgroups of an electorate are reflected proportionately in the elected body. The concept applies mainly to political divisions (Political party, political parties) among voters. The aim of such systems is that all votes cast contribute to the result so that each representative in an assembly is mandated by a roughly equal number of voters, and therefore all votes have equal weight. Under other election systems, a bare Plurality (voting), plurality or a scant majority in a district are all that are used to elect a member or group of members. PR systems provide balanced representation to different factions, usually defined by parties, reflecting how votes were cast. Where only a choice of parties is allowed, the seats are allocated to parties in proportion to the vote tally or ''vote share'' each party receives. Exact proportionality is never achieved under PR systems, except by chance. The use of elector ... [...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] |
Resolvability Criterion
A voting system is called decisive, resolvable, or resolute if it ensures a low probability of tied elections. There are two different criterion that formalize this. * In Nicolaus Tideman's version of the criterion, adding one extra vote (with no tied ranks) should make the winner unique. * Douglas R. Woodall's version requires that the probability of a tied vote under an impartial culture model gives a tie approaches zero as the number of voters increases toward infinity. A non-resolvable social choice function is often only considered to be a ''partial'' electoral method, sometimes called a voting correspondence or set-valued voting rule. Such methods frequently require tiebreakers that can substantially affect the result. However, non-resolute methods can be used as a first stage to eliminate candidates before ties are broken with some other method. Methods that have been used this way include the Copeland set, the Smith set, and the Landau set. References {{voting syst ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hervé Moulin
Hervé Moulin (born 1950 in Paris) is a French mathematician who is the Donald J. Robertson Chair of Economics at the Adam Smith Business School at the University of Glasgow. He is known for his research contributions in mathematical economics, in particular in the fields of mechanism design, social choice, game theory and fair division. He has written five books and over 100 peer-reviewed articles. Moulin was the George A. Peterkin Professor of Economics at Rice University (from 1999 to 2013):, the James B. Duke Professor of Economics at Duke University (from 1989 to 1999), the University Distinguished Professor at Virginia Tech (from 1987 to 1989), and Academic Supervisor at Higher School of Economics in St. Petersburg, Russia (from 2015 to 2022). He is a fellow of the Econometric Society since 1983, and the president of the Game Theory Society for the term 2016 - 2018. He also served as president of the Society for Social Choice and Welfare for the period of 1998 t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Schulze's 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 voting, ranked-choice voting rule developed by Markus Schulze. The Schulze method is a Condorcet method, 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 tie, cyclic ties by using indirect victories. The idea is that if Alice and Bob, 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 (operating system), Ubuntu, Gentoo Linux, Gentoo, Pira ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Minimax Condorcet
In voting systems, the Minimax Condorcet method is a single-winner ranked-choice voting method that always elects the majority (Condorcet) winner. Minimax compares all candidates against each other in a round-robin tournament, then ranks candidates by their worst election result (the result where they would receive the fewest votes). The candidate with the ''largest'' (maximum) number of votes in their ''worst'' (minimum) matchup is declared the winner. Description of the method The Minimax Condorcet method selects the candidate for whom the greatest pairwise score for another candidate against him or her is the least such score among all candidates. Football analogy Imagine politicians compete like football teams in a round-robin tournament, where every team plays against every other team once. In each matchup, a candidate's score is equal to the number of voters who support them over their opponent. Minimax finds each team's (or candidate's) worst game – the one wher ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
