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Duggan–Schwartz Theorem
The Duggan–Schwartz theorem (named after John Duggan and Thomas Schwartz) is a result about voting systems designed to choose a nonempty set of winners from the preferences of certain individuals, where each individual ranks all candidates in order of preference. It states that for three or more candidates, at least one of the following must hold: #The system is not anonymous (some voters are treated differently from others). #The system is imposed (some candidates can never win). #Every voter's top preference is in the set of winners. #The system can be manipulated by either an optimistic voter, one who can cast a ballot that would elect some candidate to a higher rank than all of those candidates who would have been elected if that voter had voted honestly; or by a pessimistic voter, one who can cast a ballot that would exclude some candidate to a lower rank than all of those candidates who were elected due that voter voting strategically. The first two conditions are consider ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Duggan (political Scientist)
John Duggan may refer to: * John Duggan (rugby, born 1929) (1929–2022), English former rugby union and rugby league footballer * John Duggan (rugby union, born 1948), Irish former Leicester Tigers winger * John Duggan (bishop) (1918–2000), Bishop of Tuam, Killala, and Achonry, 1970–1985 * Jack Duggan (politician) (1910–1993), Australian politician for Electoral district of Toowoomba West * Johnny Duggan (jockey), on racehorse Gold and Black * John Duggan, main character in the TV series '' Duggan'' * John Duggan, character in the TV series ''The Thick of It'' * Jack Duggan (ice hockey) (1897–1977), ice hockey player * Jack Duggan (politician) (1910–1993), member of the Queensland Legislative Assembly * John Duggan (political scientist) of the Duggan–Schwartz theorem The Duggan–Schwartz theorem (named after John Duggan and Thomas Schwartz) is a result about voting systems designed to choose a nonempty set of winners from the preferences of certain individuals ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thomas Schwartz (political Scientist)
Thomas Allen Schwartz (born March 7, 1945) is a retired United States Army four-star general who commanded the United States Army Forces Command from 1998 to 1999 and United States Forces Korea from 1999 to 2002. Education Schwartz attended Cretin High School (now Cretin-Derham Hall High School) in Saint Paul, Minnesota. Military career Schwartz was born on March 7, 1945, in St. Paul, Minnesota. He was commissioned in the infantry following graduation from the United States Military Academy in 1967. He served as a platoon leader and company commander with the 2nd Battalion, 505th Infantry in Vietnam from August 1968 to October 1969, earning both a Silver Star and a Purple Heart. In addition to Forces Command and United States Forces Korea, Schwartz also commanded III Corps and the 4th Infantry Division from October 1993 to November 1995. Schwartz holds master's degrees from Duke University and the Naval War College. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Voting System
An electoral system or voting system is a set of rules that determine how elections and referendums are conducted and how their results are determined. Electoral systems are used in politics to elect governments, while non-political elections may take place in business, non-profit organisations 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 memb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gibbard–Satterthwaite Theorem
In social choice theory, the Gibbard–Satterthwaite theorem is a result published independently by philosopher Allan Gibbard in 1973 and economist Mark Satterthwaite in 1975. It deals with deterministic ordinal electoral systems that choose a single winner. It states that for every voting rule, one of the following three things must hold: # The rule is dictatorial, i.e. there exists a distinguished voter who can choose the winner; or # The rule limits the possible outcomes to two alternatives only; or # The rule is susceptible to tactical voting: in certain conditions, a voter's sincere ballot may not best defend their opinion. While the scope of this theorem is limited to ordinal voting, Gibbard's theorem is more general, in that it deals with processes of collective decision that may not be ordinal: for example, voting systems where voters assign grades to candidates. Gibbard's 1978 theorem and Hylland's theorem are even more general and extend these results to non-determini ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arrow's Impossibility Theorem
Arrow's impossibility theorem, the general possibility theorem or Arrow's paradox is an impossibility theorem in social choice theory that states that when voters have three or more distinct alternatives (options), no ranked voting electoral system can convert the ranked preferences of individuals into a community-wide (complete and transitive) ranking while also meeting the specified set of criteria: '' unrestricted domain'', '' non-dictatorship'', ''Pareto efficiency'', and ''independence of irrelevant alternatives''. The theorem is often cited in discussions of voting theory as it is further interpreted by the Gibbard–Satterthwaite theorem. The theorem is named after economist and Nobel laureate Kenneth Arrow, who demonstrated the theorem in his doctoral thesis and popularized it in his 1951 book ''Social Choice and Individual Values''. The original paper was titled "A Difficulty in the Concept of Social Welfare". In short, the theorem states that no rank-order electoral syst ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Voting Theory
Social choice theory or social choice is a theoretical framework for analysis of combining individual opinions, preferences, interests, or welfares to reach a ''collective decision'' or ''social welfare'' in some sense.Amartya Sen (2008). "Social Choice,". ''The New Palgrave Dictionary of Economics'', 2nd EditionAbstract & TOC./ref> Whereas choice theory is concerned with individuals making choices based on their preferences, social choice theory is concerned with how to translate the preferences of individuals into the preferences of a group. A non-theoretical example of a collective decision is enacting a law or set of laws under a constitution. Another example is voting, where individual preferences over candidates are collected to elect a person that best represents the group's preferences. Social choice blends elements of welfare economics and public choice theory. It is methodologically individualistic, in that it aggregates preferences and behaviors of individual member ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
