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Mutual Majority
The mutual majority criterion is a criterion for evaluating electoral systems. It is also known as the majority criterion for solid coalitions and the generalized majority criterion. This criterion requires that whenever a majority of voters prefer a group of candidates above all others, then the winner must be a candidate from that group. The mutual majority criterion may also be thought of as the single-winner case of Droop- Proportionality for Solid Coalitions. Formal definition Let L be a subset of candidates. A solid coalition in support of L is a group of voters who strictly prefer all members of L to all candidates outside of L. In other words, each member of the solid coalition ranks their least-favorite member of L higher than their favorite member outside L. Note that the members of the solid coalition may rank the members of L differently. The mutual majority criterion says that if there is a solid coalition of voters in support of L, and this solid coalition consist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electoral System
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, nonprofit organizations and informal organisations. These rules govern all aspects of the voting process: when elections occur, Suffrage, who is allowed to vote, Nomination rules, who can stand as a candidate, Voting method, how ballots are marked and cast, how the ballots are counted, how votes translate into the election outcome, limits on Campaign finance, 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. Some electoral systems elect a single winner to a unique position, such as prime minister, president or governor, while others elect multiple winners, such as membe ... [...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] |
Voting System
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, nonprofit organizations 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. Some electoral systems elect a single winner to a unique position, such as prime minister, president or governor, while others elect multiple winners, such as members of parliament or boards of directors. When electing a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Majority Loser Criterion
The majority loser criterion is a criterion to evaluate single-winner voting systems. The criterion states that if a majority of voters give a candidate no support, i.e. do not list that candidate on their ballot, that candidate must lose (unless no candidate is accepted by a majority of voters). Either of the Condorcet loser criterion or the mutual majority criterion implies the majority loser criterion. However, the Condorcet criterion does not imply the majority loser criterion, since the minimax method satisfies the Condorcet but not the majority loser criterion. Also, the majority criterion is logically independent from the majority loser criterion, since the plurality rule satisfies the majority but not the majority loser criterion, and the anti-plurality rule satisfies the majority loser but not the majority criterion. There is no positional scoring rule which satisfies both the majority and the majority loser criterion, but several non-positional rules, including ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Majority Winner Criterion
The majority criterion is a voting system criterion applicable to voting rules over ordinal preferences required that if only one candidate is ranked first by over 50% of voters, that candidate must win. Some methods that comply with this criterion include any Condorcet method, instant-runoff voting, Bucklin voting, plurality voting, and approval voting. The mutual majority criterion is a generalized form of the criterion meant to account for when the majority prefers multiple candidates above all others; voting methods which pass majority but fail mutual majority can encourage all but one of the majority's preferred candidates to drop out in order to ensure one of the majority-preferred candidates wins, creating a spoiler effect. Difference from the Condorcet criterion By the majority criterion, a candidate ''C'' should win if a majority of voters answers affirmatively to the question "Do you (strictly) prefer ''C'' to every other candidate?" The Condorcet criterion gives ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bucklin Voting
Bucklin voting is a class of voting methods that can be used for single-member and multi-member districts. As in highest median rules like the majority judgment, the Bucklin winner will be one of the candidates with the highest median ranking or rating. It is named after its original promoter, the Georgist politician James W. Bucklin of Grand Junction, Colorado, and is also known as the Grand Junction system. Voting process Bucklin rules varied, but here is a typical example: Voters are allowed rank preference ballots (first, second, third, etc.). First choice votes are first counted. If one candidate has a majority, that candidate wins. Otherwise the second choices are added to the first choices. Again, if a candidate with a majority vote is found, the winner is the candidate with the most votes accumulated. Lower rankings are added as needed. A majority is determined based on the number of valid ballots. Since, after the first round, there may be more votes cast than vot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nanson's Method
The Borda count electoral system can be combined with an instant-runoff procedure to create hybrid election methods that are called Nanson method and Baldwin method (also called Total Vote Runoff or TVR). Both methods are designed to satisfy the Condorcet criterion, and allow for incomplete ballots and equal rankings. Nanson method The Nanson method is based on the original work of the mathematician Edward J. Nanson in 1882. Nanson's method eliminates those choices from a Borda count tally that are at or below the average Borda count score, then the ballots are retallied as if the remaining candidates were exclusively on the ballot. This process is repeated if necessary until a single winner remains. If a Condorcet winner exists, they will be elected. If not, (there is a Condorcet cycle) then the preference with the smallest majority will be eliminated. Nanson's method can be adapted to handle incomplete ballots (including " plumping") and equal rankings ("bracketing") ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Instant-runoff Voting
Instant-runoff voting (IRV; ranked-choice voting (RCV), preferential voting, alternative vote) is a single-winner ranked voting election system where Sequential loser method, one or more eliminations are used to simulate Runoff (election), runoff elections. When no candidate has a majority of the votes in the first round of counting, each following round eliminates the candidate with the fewest First-preference votes, first-preferences (among the remaining candidates) and transfers their votes if possible. This continues until one candidate accumulates a majority of the votes still in play. Instant-runoff voting falls under the plurality-based voting-rule family, in that under certain conditions the candidate with the least votes is eliminated, making use of secondary rankings as contingency votes. Thus it is related to the Runoff election, two-round runoff system and the exhaustive ballot. IRV could also be seen as a single-winner equivalent of Single transferable vote, sin ... [...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] |
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] |
Contingent Vote
The contingent vote is a two-stage electoral system that elects a single representative, in which the winner receives a majority of votes. It uses ranked voting. The voter ranks the candidates in order of preference, and when the votes are first counted, only first preferences are counted. If no candidate has a majority (more than half) of the votes cast, then all but the two leading candidates are eliminated and the votes that had been received by the eliminated candidates are transferred to whichever of the two remaining candidates are marked as the next preference. The contingent vote can be considered a compressed or "instant" form of the two-round system (runoff system), in which the second "round" is conducted without the need for voters to go to the polls a second time. For this reason, the term ''instant-runoff voting'' has been used for this system, though this conflicts with the more common use of that term. The contingent vote election system also has similariti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
