|
Schulze STV
Schulze STV is a draft single transferable vote (STV) ranked voting system designed to achieve proportional representation.Markus SchulzeFree Riding and Vote Management under Proportional Representation by Single Transferable Vote/ref> 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 not used in parliamentary elections. The system is based on Schulze's investigations into vote management and free riding.Markus SchulzeFree Riding ''Voting matters'', issue 18, pages 2–8, June 2004 When a voter prefers a popular candidate, there is a strategic 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). According to Schulze, vote management is party coordination of free riding. Although Schul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Single Transferable Vote
Single transferable vote (STV) is a multi-winner electoral system in which voters cast a single vote in the form of a ranked-choice ballot. Voters have the option to rank candidates, and their vote may be transferred according to alternate preferences if their preferred candidate is eliminated, 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. Under STV, no one party or voting bloc can take all the seats in a district unless the number of seats in the district is very small or almost all the votes cast are cast for one party's candidates (which is seldom the case). This makes it different from other district voting systems. In majoritarian/plurality systems such as first-past-the-post (FPTP), instant-runoff voting (IRV; also known as the alternative vote), block voting, and ranked-vote ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
First Past The Post
In a first-past-the-post electoral system (FPTP or FPP), formally called single-member plurality voting (SMP) when used in single-member districts or informally choose-one voting in contrast to ranked voting, or score voting, voters cast their vote for a candidate of their choice, and the candidate who receives the most votes wins even if the top candidate gets less than 50%, which can happen when there are more than two popular candidates. As a winner-take-all method, FPTP often produces disproportional results (when electing members of an assembly, such as a parliament) in the sense that political parties do not get representation according to their share of the popular vote. This usually favours the largest party and parties with strong regional support to the detriment of smaller parties without a geographically concentrated base. Supporters of electoral reform are generally highly critical of FPTP because of this and point out other flaws, such as FPTP's vulnerability t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Warren Method
The single transferable vote (STV) is a voting system based on proportional representation and ranked voting. Under STV, an elector's vote is initially allocated to his or her most-preferred candidate. After candidates have been either elected (''winners'') by reaching ''quota'' or eliminated (''losers''), ''surplus'' votes are transferred from winners to remaining candidates (''hopefuls'') according to the surplus ballots' ordered preferences. The system minimizes "wasted" votes and allows for approximately proportional representation without the use of party lists. A variety of algorithms (methods) carry out these transfers. Voting When using an STV ballot, the voter ranks the candidates on the ballot. For example: Some, but not all single transferable vote systems require a preference to be expressed for every candidate. Quota The quota (sometimes called the threshold) is the number of votes that ensure the election of a candidate. Some may be elected without quota but a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meek Method
The single transferable vote (STV) is a voting system based on proportional representation and ranked voting. Under STV, an elector's vote is initially allocated to his or her most-preferred candidate. After candidates have been either elected (''winners'') by reaching ''quota'' or eliminated (''losers''), ''surplus'' votes are transferred from winners to remaining candidates (''hopefuls'') according to the surplus ballots' ordered preferences. The system minimizes "wasted" votes and allows for approximately proportional representation without the use of party lists. A variety of algorithms (methods) carry out these transfers. Voting When using an STV ballot, the voter ranks the candidates on the ballot. For example: Some, but not all single transferable vote systems require a preference to be expressed for every candidate. Quota The quota (sometimes called the threshold) is the number of votes that ensure the election of a candidate. Some may be elected without quota but ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Voting System Criterion
Electoral systems are the rules for conducting elections, a main component of which is the algorithm for determining the winner (or several winners) from the ballots cast. This article discusses methods and results of comparing different electoral systems, both those which elect a unique candidate in a 'single-winner' election and those which elect a group of representatives in a multiwinner election. There are 4 main types of reasoning which have been used to try to determine the best voting method: # Argument by example # Adherence to logical criteria # Results of simulated elections # Results of real elections Expert opinions on single-winner voting methods In 2010, a panel of 22 experts on voting procedures were asked: "What is the best voting rule for your town to use to elect the mayor?". One member abstained. Approval voting was used to decide between 18 single-winner voting methods. The ranking (with number ''N'' of approvers from a maximum of 21) of the various syst ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Later-no-harm Criterion
The later-no-harm criterion is a voting system criterion formulated by Douglas Woodall. Woodall defined the criterion as " ding a later preference to a ballot should not harm any candidate already listed." For example, a ranked voting method in which a voter adding a 3rd preference could reduce the likelihood of their 1st preference being selected, fails later-no-harm. Voting systems that fail the later-no-harm criterion are vulnerable to the tactical voting strategies called bullet voting and burying, which can deny victory to a sincere Condorcet winner. However, the fact that all cardinal voting methods fail the later-no-harm criterion is essential to their favoring consensus options (broad, moderate support) over majoritarian options (narrow, strong support). Complying methods Two-round system, Single transferable vote, Instant Runoff Voting, Contingent vote, Minimax Condorcet (a pairwise opposition variant which does not satisfy the Condorcet Criterion), and Descending S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Participation Criterion
The participation criterion is a voting system criterion. Voting systems that fail the participation criterion are said to exhibit the no show paradox and allow a particularly unusual strategy of tactical voting: abstaining from an election can help a voter's preferred choice win. The criterion has been defined as follows: * In a deterministic framework, the participation criterion says that the addition of a ballot, where candidate A is strictly preferred to candidate B, to an existing tally of votes should not change the winner from candidate A to candidate B. * In a probabilistic framework, the participation criterion says that the addition of a ballot, where each candidate of the set X is strictly preferred to each other candidate, to an existing tally of votes should not reduce the probability that the winner is chosen from the set X. Plurality voting, approval voting, range voting, and the Borda count all satisfy the participation criterion. All Condorcet methods, Bucklin vo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monotonicity Criterion
The monotonicity criterion is a voting system criterion used to evaluate both single and multiple winner ranked voting systems. A ranked voting system is monotonic if it is neither possible to prevent the election of a candidate by ranking them higher on some of the ballots, nor possible to elect an otherwise unelected candidate by ranking them lower on some of the ballots (while nothing else is altered on any ballot).D R Woodall"Monotonicity and Single-Seat Election Rules" ''Voting matters'', Issue 6, 1996 That is to say, in single winner elections no winner is harmed by up-ranking and no loser is helped by down-ranking. Douglas Woodall called the criterion mono-raise. Raising a candidate on some ballots ''while changing'' the orders of other candidates does ''not'' constitute a failure of monotonicity. E.g., harming candidate by changing some ballots from to would violate the monotonicity criterion, while harming candidate by changing some ballots from to would not. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Instant-runoff Voting
Instant-runoff voting (IRV) is a type of ranked preferential voting method. It uses a majority voting rule in single-winner elections where there are more than two candidates. It is commonly referred to as ranked-choice voting (RCV) in the United States (although there are other forms of ranked voting), preferential voting in Australia, where it has seen the widest adoption; in the United Kingdom, it is generally called alternative vote (AV), whereas in some other countries it is referred to as the single transferable vote, which usually means only its multi-winner variant. All these names are often used inconsistently. Voters in IRV elections rank the candidates in order of preference. Ballots are initially counted for each voter's top choice. If a candidate has more than half of the first-choice votes, that candidate wins. If not, then the candidate with the fewest votes is eliminated, and the voters who selected the defeated candidate as a first choice then have their vot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Droop Quota
The Droop quota is the quota most commonly used in elections held under the single transferable vote (STV) system. It is also sometimes used in elections held under the largest remainder method of party-list proportional representation (list PR). In an STV election the quota is the minimum number of votes a candidate must receive in order to be elected. Any votes a candidate receives above the quota are transferred to another candidate. The Droop quota was devised in 1868 by the English lawyer and mathematician Henry Richmond Droop (1831–1884) as a replacement for the earlier Hare quota. Today the Droop quota is used in almost all STV elections, including the forms of STV used in India, the Republic of Ireland, Northern Ireland, Malta and Australia, among other places, and is also used to allocate seats via the largest remainder model in South Africa. The Droop quota is very similar to the simpler Hagenbach-Bischoff quota, which is also sometimes loosely referred to as the 'Dro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ranked Voting
The term ranked voting (also known as preferential voting or ranked choice voting) refers to any voting system in which voters ranking, rank their candidates (or options) in a sequence of first or second (or third, etc.) on their respective ballots. Ranked voting systems differ on the basis of how the ballots are marked, how the preferences are tabulated and counted, how many seats are filled, and whether voters are allowed to rank candidates equally. An electoral system that uses ranked voting uses one of the many available counting methods to select the winning candidate or candidates. There is also variation among ranked voting electoral systems in that in some ranked voting systems, officials require voters to rank a set number of candidates, sometimes all of them; in others, citizens may rank as many candidates as they see fit. Election of single members using ranked votes is often instant-runoff voting. Election of multiple members using ranked votes is usually single tr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Single Transferable Vote
Single transferable vote (STV) is a multi-winner electoral system in which voters cast a single vote in the form of a ranked-choice ballot. Voters have the option to rank candidates, and their vote may be transferred according to alternate preferences if their preferred candidate is eliminated, 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. Under STV, no one party or voting bloc can take all the seats in a district unless the number of seats in the district is very small or almost all the votes cast are cast for one party's candidates (which is seldom the case). This makes it different from other district voting systems. In majoritarian/plurality systems such as first-past-the-post (FPTP), instant-runoff voting (IRV; also known as the alternative vote), block voting, and ranked-vote ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
