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Socially Optimal Winner
Social utility efficiency (SUE) or voter satisfaction efficiency (VSE) is a metric for comparing Electoral system, voting methods which compares them based on the average well-being of voters. Definition Social utility efficiency is defined as the ratio between the social utility of the candidate who is actually elected by a given voting method and that of the candidate who would maximize social utility, where E[] is the expected value over many iterations of the sum of all voter utilities for a given candidate: \operatorname= \frac A voting method with 100% efficiency would always pick the candidate that maximizes voter utility. A method that chooses a winner randomly would have efficiency of 0%, and a (pathological) method that did worse than a random pick would have less than 0% efficiency. SUE is not only affected by the voting method, but is a function of the number of voters, number of candidates, and of any strategies used by the voters. History The concept was origi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Merrill 1984 Figure 3 Social-Utility Efficiency For A Random Society
Merrill may refer to: Places in the United States *Merrill Field, Anchorage, Alaska *Merrill, Iowa *Merrill, Maine *Merrill, Michigan *Merrill, Mississippi, an unincorporated community near Lucedale in George County *Merrill, Oregon *Merrill, Wisconsin *Merrill (town), Wisconsin *Merrill Township, Michigan *Merrill Township, North Dakota *Merrill College at the University of California, Santa Cruz People *Merrill (given name) *Merrill (surname) Other uses *Merrill (company), a division of Bank of America *Skidmore, Owings and Merrill, architectural firm *USS Merrill (DD-976), USS ''Merrill'' (DD-976) *Nine men's morris, a strategy board game also called ''Merrills'' * Merrill (crater) * Merrill, Characters_of_Dragon_Age_II#Merrill, a companion character in ''Dragon Age II'' See also * Merril * Marill, a Pokémon * Merrell (other) {{disambig, geo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Two-round System
The two-round system (TRS or 2RS), sometimes called ballotage, top-two runoff, or two-round plurality, is a single-winner electoral system which aims to elect a member who has support of the majority of voters. The two-round system involves one or two rounds of choose-one voting, where the voter marks a single favorite candidate in each round. If no one has a majority of votes in the first round, the two candidates with the most votes in the first round move on to a second election (a second round of voting). The two-round system is in the family of plurality voting systems that also includes single-round plurality (FPP). Like instant-runoff (ranked-choice) voting and first past the post, it elects one winner. The two-round system first emerged in France and has since become the most common single-winner electoral system worldwide. Despite this, runoff-based rules like the two-round system and RCV have faced criticism from social choice theorists as a result of their suscep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Condorcet Efficiency
Condorcet efficiency is a measurement of the performance of voting methods. It is defined as the percentage of elections for which the Condorcet winner (the candidate who is preferred over all others in head-to-head races) is elected, provided there is one. A voting method with 100% efficiency would always pick the Condorcet winner, when one exists, and a method that never chose the Condorcet winner would have 0% efficiency. Efficiency is not only affected by the voting method, but is a function of the number of voters, number of candidates, and of any strategies used by the voters. It was initially developed in 1984 by Samuel Merrill III, along with social utility efficiency. A related, generalized measure is Smith efficiency, which measures how often a voting method elects a candidate in the Smith set. Smith efficiency can be used to differentiate between voting methods across ''all'' elections, because unlike the Condorcet winner, the Smith set always exists. A 100% Sm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Random Ballot
A random ballot or random dictatorship is a randomized electoral system where the election is decided on the basis of a single randomly-selected ballot. A closely-related variant is called random serial (or sequential) dictatorship, which repeats the procedure and draws another ballot if multiple candidates are tied on the first ballot. Random dictatorship was first described in 1977 by Allan Gibbard, who showed it to be the unique social choice rule that treats all voters equally while still being strategyproof in all situations. Its application to elections was first described in 1984 by Akhil Reed Amar. The rule is rarely, if ever, proposed as a genuine electoral system, as such a method (in Gibbard's words) "leaves too much to chance". However, the rule is often used as a tiebreaker to encourage voters to cast honest ballots, and is sometimes discussed as a thought experiment. Random dictatorship and random serial dictatorship The dictatorship rule is obviously unfair, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bayesian Regret
In stochastic game theory, Bayesian regret is the expected difference ("regret") between the utility of a given strategy and the utility of the best possible strategy in hindsight—i.e., the strategy that would have maximized expected payoff if the true underlying model or distribution were known. This notion of regret measures how much is lost, on average, due to uncertainty or imperfect information. Etymology The term ''Bayesian'' refers to Thomas Bayes (1702–1761), who proved a special case of what is now called Bayes' theorem, who provided the first mathematical treatment of a non-trivial problem of statistical data analysis using what is now known as Bayesian inference. Economics This term has been used to compare a random buy-and-hold strategy to professional traders' records. This same concept has received numerous different names, as the New York Times notes: "In 1957, for example, a statistician named James Hanna called his theorem Bayesian Regret. He had been pre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Score Voting
Score voting, sometimes called range voting, is an electoral system for single-seat elections. Voters give each candidate a numerical score, and the candidate with the highest average score is elected. Score voting includes the well-known approval voting (used to calculate approval ratings), but also lets voters give partial (in-between) approval ratings to candidates. Usage Political use Historical A crude form of score voting was used in some elections in ancient Sparta, by measuring how loudly the crowd shouted for different candidates. This has a modern-day analog of using clapometers in some television shows and the judging processes of some athletic competitions. Beginning in the 13th century, the Republic of Venice elected the Doge of Venice using a multi-stage process with multiple rounds of score voting. This may have contributed to the Republic's longevity, being partly responsible for its status as the longest-lived democracy in world history. Score voting w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
STAR Voting
STAR voting is an electoral system for single-seat elections. The name (an allusion to Star (classification), star ratings) stands for "Score Then Automatic Runoff", referring to the fact that this system is a combination of score voting, to pick two finalists with the highest total scores, followed by an "automatic runoff" in which the finalist who is preferred on more ballots wins. It is a type of cardinal voting electoral system. Method In STAR, voters are given a score ballot (or ratings ballot) on which each voter scores candidates with a number from 0 up to 5, with 0 representing "worst" and 5 representing "best". The scores for each candidate are then summed, and the two highest-scored candidates are selected as finalists. In the automatic runoff round, the finalist who was given a higher score on a greater number of ballots is selected as the winner. Usage The concept was first proposed in October 2014 by Mark Frohnmayer, and was initially called score runoff voting ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hierarchical Clustering
In data mining and statistics, hierarchical clustering (also called hierarchical cluster analysis or HCA) is a method of cluster analysis that seeks to build a hierarchy of clusters. Strategies for hierarchical clustering generally fall into two categories: * Agglomerative: Agglomerative: Agglomerative clustering, often referred to as a "bottom-up" approach, begins with each data point as an individual cluster. At each step, the algorithm merges the two most similar clusters based on a chosen distance metric (e.g., Euclidean distance) and linkage criterion (e.g., single-linkage, complete-linkage). This process continues until all data points are combined into a single cluster or a stopping criterion is met. Agglomerative methods are more commonly used due to their simplicity and computational efficiency for small to medium-sized datasets . * Divisive: Divisive clustering, known as a "top-down" approach, starts with all data points in a single cluster and recursively splits the clu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Black's Method
Black's method is an election method proposed by Duncan Black in 1958 as a compromise between the Condorcet method and the Borda count. This method selects a Condorcet winner. If a Condorcet winner does not exist, then the candidate with the highest Borda score is selected. Properties Among methods satisfying the majority criterion, Black's method gives the minimum power to the majority and hence the method is best at protecting minorities. Satisfied criteria Black's method satisfies the following criteria: * Unrestricted domain * Non-imposition ( a.k.a. citizen sovereignty) * Non-dictatorship * Homogeneity * Condorcet criterion * Majority criterion * Pareto criterion ( a.k.a. unanimity) * Monotonicity criterion * Majority loser criterion * Condorcet loser criterion * Reversal symmetry * Resolvability criterion * Polynomial time Failed criteria Black's method does not satisfy the following criteria: * Mutual majority criterion * Smith criterion * Participation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coombs' Method
Coombs' method is a ranked voting system. Like instant-runoff (IRV-RCV), Coombs' method is a sequential-loser method, where the last-place finisher according to one method is eliminated in each round. However, unlike in instant-runoff, each round has electors voting against their least-favorite candidate; the candidate ranked last by the most voters is eliminated. The method fails several voting system criteria, including Condorcet's majority criterion, monotonicity, participation, and clone-independence. However, it does satisfy Black's single-peaked median voter criterion. History The method was popularized by Clyde Coombs. It was described by Edward J. Nanson as the "Venetian method" (which should not be confused with the Republic of Venice's use of score voting in elections for Doge). Procedures Each voter rank-orders all of the candidates on their ballot. Otherwise, the candidate ranked last by the largest number ( plurality) of voters is eliminated, making eac ... [...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] |
