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Избирателна система Избирателната система или системата на гласуване е метод, чрез който избирателите могат да направят своя избор между различни варианти, често на избори или на политически референдум. Системата на гласуване се състои от правила, определящи валидността на гласуването и също как да бъдат преброени и обобщени гласовете за да се получи крайният резултат. Тъй като гласуването включва преброяване, то е алгоритмично по своя характер. По-разпространени избирателни системи са пропорционалната и мажоритарната, като са възможни различни техни варианти като например преференциалната и смесената избирателни системи. В зависимост от търсеният резултат от изборите, може да се разграничат едномандатни избирателни системи (когато резултатът е единствен вариант) и многомандатни избирателни системи. В зависимост от избрания алгоритъм, обичайните "мажоритарни" системи могат да имат резултати, които не се подкрепят от мнозинството. Ако се избира само между два варианта, победителят може да се определи по правилото за мнозинство. Обаче, ако имаме три или повече варианта, може да няма вариант, който да се предпочита от мнозинството. Простият избор между варианти не позволява на избирателите да изразят подредбата или величината на техните предпочитания. Различните избирателни системи могат да имат твърде различаващи се резултати, особено когато няма ясно предпочитан от мнозинството вариант. Съдържание - 1 Елементи - 2 Многомандатни системи - 3 Едномандатни системи - 4 Външни препратки Елементи[редактиране | edit source] Избирателната система определя формата на бюлетината, множеството от позволените варианти и алгоритъмът за изчисление на резултатите. Резултатът може да бъде от единствен избран или да има множество от избрани варианти. Избирателната система може да определя как се разпределя тежестта на избирателната сила сред избирателите и как избирателите се разпределят по подгрупи (избирателни райони), в които гласовете се броят отделно. Обикновено се счита, че конкретният начин на провеждане на избори не е част от избирателната система. Например избирателната система може да определя бюлетината абстрактно, но да не казва дали тя трябва физически да изглежда като лист хартия, цветна топка или компютърен екран. Избирателната система не определя как да се запази тайната на гласуването, как да се преброят точно гласовете и кой има право да гласува. Това са елементи, конкретизирани за самите избори. Бюлетина[редактиране | edit source] Различните избирателни системи предлагат различни форми за изразяване на волята на избирателя. При някои избирателни системи избирателите трябва да маркират вариантите, при други подреждат списъкът от вариантите по реда на своето предпочитание, а при трети оценяват отделно всеки от вариантите. Също така избирателните системи, при които се маркира вариант, могат да се разделят на такива, при които избирателите могат да маркират само един вариант, и такива, при които избирателите могат да маркират произволен брой варианти. Някои системи дори позволяват маркирането на един и същ вариант няколко пъти. Като особени случаи могат да се посочат системи, при които има допълнителни специални варианти, като възможност за вписване на допълнителен вариант, вариант "никой от посочените" или посочване на недоверие към варианта. Варианти[редактиране | edit source] При някои системи може да се извърши предварително гласуване за да се определи кои варианти да останат в бюлетината. Тежест на вота[редактиране | edit source] Повечето избори се правят на принципа "един избирател, един глас", т.е. всички избиратели имат равна тежест при гласуване. Това, обаче, не е вярно за всички избори. При гласуването на Общо събрание на Акционерно дружество обикновено гласовете се претеглят според количеството акции, притежавани от гласувалите, което променя принципа на "една акция, един глас". Възможно е да има и други причини за различия в тежестта на вота, например увеличаване на тежестта на вота за по-висшестоящите членове на дадената организация. Тежестта на вота не трябва да се бърка с избирателната сила. В някои ситуации определени групи от избиратели гласуват по организиран начин (например когато са от една партия), за да постигнат обща цел на резултата. Избирателната сила измерва способността на групата да повлияе на резултата. Отделни групи могат да създават коалиции, с цел увеличаване на избирателната си сила. Статукво[редактиране | edit source] Някои избирателни системи поставят минимални изисквания към резултатите, така че да се избегнат честите промени в установеното състояние (статукво). Пример за такова изискване е наличието на мнозинство за да се приеме резултата. Крайният вариант на това изискване е единодушието, когато е нужно всеки гласувал да подкрепя крайният резултат. Един друг механизъм за запазване на статуквото е изискването за кворум, което поставя минимум върху броя на участниците в гласуването спрямо общия брой на имащите право да гласуват. Това може да предизвика използването на стратегии за обезкуражаване на гласоподавателите с цел да не се постигне кворум. Избирателни райони[редактиране | edit source] Често целта на изборите е да се избере група от няколко победители. Това може да стане като се проведе еднократно избор и да се определят победителите според всички подадени гласове. Друга възможност е да се разделят гласоподавателите по избирателни райони, които избират измежду различни варианти и определят различни победители. Първият подход всъщност представлява частен случай, при който имаме само един избирателен район. Начинът на определяне на избирателните райони и съответстващите им мандати може силно да повлияе на резултатите. Обикновено избирателните райони получават мандати според броя на населението в тях. Промяната на броя мандати или на границите на избирателните райони е важен въпрос, понеже може да доведе до различни коефициенти на отношението между мандатите и броя на населението или манипулиране с цел изкривяване на резултатите. Многомандатни системи[редактиране | edit source] Изборите, които имат повече от един победител, като тези за законодателен орган, имат различни практически ефекти от тези с един победител. Често участниците в многомандатни избори са по-загрижени за състава на законодателният орган, отколкото за конкретните избраници. По тази причина е обичайно многомандатните системи да са пропорционални, при които ако дадена група (партия) получи Х% от гласовете, то тя ще има приблизително Х% от избраниците. Не всички многомандатни системи са пропорционални. Пропорционални системи[редактиране | edit source] Истински пропорционалните методи се опитват да гарантират, че всеки от победителите представлява приблизително един и същ брой избиратели. Тази бройка се нарича квота. Например, ако квотата е 1000 избиратели, тогава всеки избраник ще представлява мнението на 1000 избиратели в границите на някаква грешка. Повечето пропорционални системи използват партийни листи, като избирателите гласуват за партии вместо за отделни кандидати. За всяка квота, която спечели партията, се избира един от техните кандидати. Възможно е да има разлики в методите, използвани за определяне на квотата и закръгляне, като целта е да има точно определен брой избраници. Методите за определяне на спечелените места могат да се разделят на методи на най-високите средни и методи на най-големия остатък. Методите на най-големия остатък определят квота въз основа на броя на избирателите, докато методите на най-високите средни определят квотата косвено, като се извършва деление на получените гласове от всяка партия на предварително определена поредица от числа. Системите с партийни листи, независимо от метода за определяне на спечелените места, могат да бъдат с отворени или затворени листи. При система с отворени листи, избирателите могат да определят кои кандидати на партията ще заемат спечелените места. При система със затворени листи, спечелените места се разпределят на кандидатите в определен ред, който е избран от партията. Възможно е да се използва и смесен тип система с част от избраниците, определени по списък на партията, а останалите са победителите от регионалните избори. За разлика от системите с партийни листи, системата Eдиничен прехвърляем вот (STV) е пропорционална система, при която избирателите подреждат отделните кандидати по реда на своето предпочитание. Тази система не изисква кандидатите да са групирани в политически партии. Различните пропорционални системи ползват различни географски разпределения. При някои системи с партийни листи или STV системи, всички кандидати са в общ списък, от който избират всички гласоподаватели. При други има разделение на множество многомандатни райони, и се търси баланс между по-високата точност в пропорциите, когато имаме по-големи райони, и по-доброто отразяване на географските особености, когато имаме малки райони. При споменатите по-горе смесени системи имаме част от победителите, която е определена от гласуването по районите, а останалите победители са от общата листа. Има и системи с бипропорционално разпределение, които предлагат висока пропорционалност, дори ако има райони само с един избирател, понеже резултатите от всеки район се коригират чрез прехвърляне на гласове на същата партия от един район в друг. Смесени системи[редактиране | edit source] Тези системи се наричат още “полупропорционални” или “полумажоритарни”, в зависимост от това от коя система произхождат първоначално. Една от тези алтернативни системи се нарича Кумулативен глас (CV). При нея всеки гласоподавател има n гласа, където n е броят на мандатите (също е възможно системата да дава право на повече гласове). Гласуващите разпределят гласовете си между кандидатите, като могат да дадат на един кандидат повече от един глас. Тя се счита за пропорционална, понеже позволява коалициите, които имат подкрепата на m/(n+1) от избирателите да получи гарантирани m мандата от общо n. Например при избори на 3 мандата, 3/4 от избирателите, които са обединени зад 3 кандидатури, могат да осигурят и 3-те мандата. За разлика от тази система, при мажоритарната система с блокирана (неизменяема) листа коалицията има нужда само от 50%+1 за да спечели всички мандати. Кумулативният глас е обичайно използвана система при случаи на избиратели с различна тежест на гласа, като например при акционерните дружества. Кумулативният глас не е напълно пропорционална система, понеже страда от ефекта на разцепване на гласовете също като мажоритарните системи. Ако има твърде много кандидати с подобни възгледи, те могат да разпределят помежду си гласовете на поддържащите ги избиратели, при което всеки от тях ще получи по-малко гласове и може да не бъде избран. Затова степента на пропорционалност на резултата зависи от добрата координация на избирателите. Системата на Ограниченият глас е многомандатна система, която дава на избирателите по-малко гласове, отколкото е броят на мандатите. Най-опростената и разпространена форма на тази система е Единичен непрехвърляем вот (SNTV). Тя може да се счита за специална разновидност на кумулативният глас, при която глас може да се даде само на един кандидат. При нея, обаче, връзката между предпочитанията на избирателите и резултата е по-скоро във вид на статистически разпределения. Например при избор за 4 мандата, всеки кандидат се нуждае от 20% за да бъде избран. Тогава при кумулативният глас, коалиция от 40% от избирателите може да спечели 2 от 4-те мандата, като всеки избирател раздели гласовете си по равно между 2-та кандидата. За сравнение, при SNTV всеки избирател гласува само за един от кандидатите и статистически може да се приеме, че гласовете ще се разделят по равно, постигайки 20% за всеки от кандидатите, но това е само вероятност, а не гарантиран резултат. Мажоритарни системи[редактиране | edit source] Съществуват многомандатни избирателни системи, които представляват елементарно разширение на едномандатни системи, без изрично да се търси пропорционалност в резултата. При избори с блокирана (неизменяема) листа, ако от даден избирателен район могат да се изберат N мандата, всеки избирател има N гласа и се избират N-те кандидата, които имат най-много гласове. Резултатите от този вид избори имат склонност да бъдат с големи разлики между групата на водещите кандидати и останалите кандидати, от което идва и названието "мажоритарни". Едномандатни системи[редактиране | edit source] Едномандатните системи могат да се разделят според типа на бюлетината. При системите с единичен вот, избирателят избира точно един конкретен вариант. При преференциалните системи избирателят подрежда вариантите по реда на предпочитание. При оценъчните системи избирателят поставя стойност-оценка за всеки от вариантите. Единичен вот или поредица от вотове[редактиране | edit source] Един от най-използваните методи досега е мажоритарната система на относително мнозинство, познат също като “на първия оказал се избран”, при който всеки избирател гласува за един вариант, и вариантът, който получи най-много гласове печели, дори ако те са по-малко от половината от всички гласове. Поредица от вотове имаме, когато се провеждат два или повече тура, а избраниците се определят по мажоритарен принцип. Мажоритарните избори в два тура - друг много популярен метод - добавя втори тур на изборите, който е между двата варианта, които са получили най-много гласове на първия тур, в случай че нито един вариант не е получил абсолютно мнозинство (над 50%). По подобен начин, в елиминационната система последният или последните няколко варианта от изборите отпадат от списъка и се провеждат нови избори с останалите варианти, докато някой от вариантите получи абсолютно мнозинство. Процедурата на първичните избори наподобява изборите в два тура. При нея се провежда първи тур, който определя тези с най-много гласове да бъдат двата варианта, които ще останат на втори тур, като се използва отворена бюлетина (с възможност за добавяне на варианти). Другата разлика е, че винаги има втори тур, понеже победител не се определя от първия тур, дори ако е събрал абсолютно мнозинство. Възможно е да се използва и лотарийна система на избор, при която на случаен принцип се избира една от пуснатите бюлетини и тя определя победителя. Това понякога се ползва и като съпътстващ метод при другите системи, когато имаме равни резултати между варианти. Преференциални системи[редактиране | edit source] Тези системи позволяват на всеки избирател да подрежда вариантите според предпочитанията си. Често не е задължително да се подредят абсолютно всички варианти, а неподредените варианти се считат за поставени на последно място. При някои системи е позволено избирателят да поставя няколко варианта на едно място. Под преференциален вот обикновено се разбира Преференциалната избирателна система с незабавна елиминация (IRV), позната също като алтернативен вот. При нея подредбата на вариантите в бюлетините се използва за симулиране на елиминационна мажоритарна система, но без да се провеждат няколко тура. След като се съберат бюлетините се определя вариантът, който има най-малък брой първи места и се елиминира. Понеже се елиминира вариантът, а не бюлетините, в последващите изчисления този вариант се игнорира и се получава ефектът, че всички варианти поставени на по-ниско място от елиминирания в дадена бюлетина, се "изкачват" с едно място нагоре. Така с няколко последователни изчисления се елиминират вариантите с най-малко гласове, докато не се стигне до вариант с абсолютно мнозинство. Методът на отметките e проста преференциална система, предложена от Жан-Шарл дьо Борда през 1781 г., при който вариантите получават числови оценки според мястото си в подредбата, след което се гледа сумата на тези оценки за всеки вариант. Тази система изглежда сякаш отразява напълно предпочитанията на избирателите, но е известна с широки възможности за спекулативен вот, добре познати от спортните квалификации. Класът на подобните на този методи е познат като Позиционни избирателни системи. Други преференциални методи са Метод на Куумс, Метод на допълнителният вот, Метод на Бъклин и Метод на Кондорсе. Методите на Кондорсе, или чифтовите методи, са вид преференциални избирателни системи, които отговарят на критерия на Кондорсе. При тези методи се сравняват два по два всички варианти и вариантът, който победи всички други варианти е Кондорсе победител. Един вариант побеждава друг, ако има повече гласували, които са поставили първия вариант по-високо от втория на бюлетината, отколкото гласували, които са сложили втория вариант по-високо. Методите на Кондорсе се групират в една категория, понеже според критерия на Кондорсе те всички трябва да имат еднакви резултати в случаите, при които съществува Кондорсе победител. Различията между отделните такива методи са в случаите, когато няма нито един непобеден вариант, от което следва, че съществува цикъл от варианти, при който всеки вариант побеждава следващия, а последния побеждава първия. Това се нарича парадокс на Кондорсе. Понеже оригиналният метод на Кондорсе е абстрактен и не решава случаите с такива цикли, специалните методи, които избират победител, дори когато не съществува Кондорсе победител, се наричат пълни Кондорсе методи. Един прост вариант на Кондорсе е Минимакс: ако няма непобеден вариант се избира вариантът, който е загубил с най-малко гласове при най-голямата си загуба. Друг прост вариант е Методът на Коупланд, при който се избира вариантът с най-много победи, по подобие на някои спортни квалификации. Методът на Кемени-Янг (познат още като метод на максималната правдоподобност), методът на Шулце ('метод на най-силният път', използван често от ИТ обществото) и методът на подредените чифтове са наскоро създадени Кондорсе методи, които удовлетворяват голям брой критерии за оценка на избирателни системи. И трите метода могат напълно или частично на подредят всички варианти от най-популярния до най-малко популярния. Оценъчни системи[редактиране | edit source] Когато избирателите могат да поставят оценки за всеки от вариантите в бюлетините, се получава още по-точно отражение на настроенията на избирателите. Това дава повече гъвкавост, но едва няколко от познатите изборни системи се възползват от това. Избирателите поставят оценка срещу всеки вариант, която може да бъде число (например от 0 до 100) или друг вид степенуване (например от "Слаб" до "Отличен"). Бюлетини с оценки могат да се използват, само ако избирателната система позволява равни оценки. Някои оценъчни системи изискват оценките в бюлетината да са различни за всеки вариант, но много избиратели предпочитат да сложат еднаква оценка на няколко варианта. При използването на ограничени оценки, избирателите поставят оценки, които са в определени граници от-до, и вариантът с най-висока осреднена оценка е победител. При мажоритарна оценка печели вариантът с най-висока медиана на оценките. При одобрителният вот избирателите могат да гласуват за произволен брой варианти, подобно на ограничените оценки и мажоритарната оценка, но позволените оценки са само 0 и 1. Външни препратки[редактиране | edit source] - Избирателни системи и процедури Лекции по право - STV ИЛИ ЕДИНИЧЕН ПРЕХВЪРЛЯЕМ ВОТ БИВОЛЪ
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Voting system A voting system or electoral system is a method by which voters make a choice between options, often in an election or on a policy referendum. A voting system enforces rules to ensure valid voting, and how votes are counted and aggregated to yield a final result. Common voting systems are majority rule, proportional representation or plurality voting with a number of variations and methods such as first-past-the-post or preferential voting. The study of formally defined voting systems is called social choice theory or voting theory, a subfield of political science, economics, or mathematics. With majority rule, those who are unfamiliar with voting theory are often surprised that another voting system exists, or that disagreements may exist over the definition of what it means to be supported by a majority[citation needed]. Depending on the meaning chosen, the common "majority rule" systems can produce results that the majority does not support. If every election had only two choices, the winner would be determined using majority rule alone. However, when there are three or more options, there may not be a single option that is most liked or most disliked by a majority. A simple choice does not allow voters to express the ordering or the intensity of their feeling. Different voting systems may give very different results, particularly in cases where there is no clear majority preference. Contents - 1 Aspects - 2 Multiple-winner methods - 3 Single-winner methods - 4 Evaluating voting systems using criteria - 5 History - 6 See also - 7 Criteria table notes - 8 References - 9 External links Aspects[edit] A voting system specifies the form of the ballot, the set of allowable votes, and the tallying method, an algorithm for determining the outcome. This outcome may be a single winner, or may involve multiple winners such as in the election of a legislative body. The voting system may also specify how voting power is distributed among the voters, and how voters are divided into subgroups (constituencies) whose votes are counted independently. The real-world implementation of an election is generally not considered part of the voting system. For example, though a voting system specifies the ballot abstractly, it does not specify whether the actual physical ballot takes the form of a piece of paper, a punch card, or a computer display. A voting system also does not specify whether or how votes are kept secret, how to verify that votes are counted accurately, or who is allowed to vote. These are aspects of the broader topic of elections and election systems. The Electoral Reform Society is a political pressure group based in the United Kingdom, believed to be the oldest organisation concerned with electoral systems in the world. The Society advocates scrapping First Past the Post (FPTP) for all National and local elections arguing that the system is 'bad for voters, bad for government and bad for democracy'. Ballot[edit] Different voting systems have different forms for allowing the individual to express his or her vote. In ranked ballot or "preference" voting systems, such as Instant-runoff voting, the Borda count, or a Condorcet method, voters order the list of options from most to least preferred. In range voting, voters rate each option separately on a scale. In plurality voting (also known as "first-past-the-post"), voters select only one option, while in approval voting, they can select as many as they want. In voting systems that allow "plumping", like cumulative voting, voters may vote for the same candidate multiple times. Some voting systems include additional choices on the ballot, such as write-in candidates, a none of the above option, or a no confidence in that candidate option. Candidates[edit] Some methods call for a primary election first to determine which candidates will be on the ballot. Weight of votes[edit] Many elections are based on the principle of "one person, one vote", meaning that every voter's votes are counted with equal weight. This is not true of all elections, however. Corporate elections, for instance, usually weight votes according to the amount of stock each voter holds in the company, changing the mechanism to "one share, one vote". Votes can also be weighted unequally for other reasons, such as increasing the voting weight of higher-ranked members of an organization. Voting weight is not the same thing as voting power. In situations where certain groups of voters will all cast the same vote (for example, political parties in a parliament), voting power measures the ability of a group to change the outcome of a vote. Groups may form coalitions to maximize voting power. In some German states, most notably Prussia and Sachsen, before 1918 there was a weighted vote system known as the Prussian three-class franchise, where the electorate would be divided into three categories based on the amount of income tax paid. Each category would have equal voting power in choosing the electors.[1] Status quo[edit] Some voting systems are weighted in themselves, for example if a super majority is required to change the status quo. An extreme case of this is unanimous consent, where changing the status quo requires the support of every voting member. If the decision is whether to accept a new member into an organization, failure of this procedure to admit the new member is called blackballing. A different mechanism that favors the status quo is the requirement for a quorum, which ensures that the status quo remains if voter participation doesn't exceed the specified threshold. Quorum requirements often depend only on the total number of votes cast, rather than the number of votes cast for the winning option. This can sometimes encourage dissenting voters to refrain from voting, in order to prevent a quorum. Constituencies[edit] Often the purpose of an election is to choose a legislative body made of multiple winners. This can be done by running a single election and choosing the winners from the same pool of votes, or by dividing up the voters into constituencies that have different options and elect different winners. Some countries, like Israel, fill their entire parliament using a single multiple-winner district (constituency), while others, like the Republic of Ireland or Belgium, break up their national elections into smaller multiple-winner districts, and yet others, like the United States or the United Kingdom, hold only single-winner elections. The Australian bicameral Parliament has single-member electorates for the legislative body (lower house) and multi-member electorates for its Senate (upper house). Some systems, like the Additional member system, embed smaller districts (constituencies) within larger ones. The way constituencies are created and assigned seats can dramatically affect the results. Apportionment is the process by which states, regions, or larger districts are awarded seats, usually according to population changes as a result of a census. Redistricting is the process by which the borders of constituencies are redrawn once apportioned. Both procedures can become highly politically contentious due to the possibility of both malapportionment, where there are unequal representative to population ratios across districts, and gerrymandering, where electoral districts are manipulated for political gain. An example of this were the UK Rotten and pocket boroughs, parliamentary constituencies that had a very small electorate — e.g. an abandoned town — and could thus be used by a patron to gain undue and unrepresentative influence within parliament. This was a feature of the unreformed House of Commons before the Great Reform Act of 1832. Multiple-winner methods[edit] Most modern democracies use some form of multiple-winner voting system, with the United States and the United Kingdom being notable exceptions. A vote with multiple winners, such as the election of a legislature, has different practical effects than a single-winner vote. Often, participants in a multiple winner election are more concerned with the overall composition of the legislature than exactly which candidates get elected. For this reason, many multiple-winner systems aim for proportional representation, which means that if a given party (or any other political grouping) gets X% of the vote, it should also get approximately X% of the seats in the legislature. Not all multiple-winner voting systems are proportional. Proportional methods[edit] Truly proportional methods make some guarantee of proportionality by making each winning option represent approximately the same number of voters. This number is called a quota. For example, if the quota is 1000 voters, then each elected candidate reflects the opinions of 1000 voters, within a margin of error. This can be measured using the Gallagher Index. Most proportional systems in use are based on party-list proportional representation, in which voters vote for parties instead of for individual candidates.[2] For each quota of votes a party receives, one of their candidates wins a seat on the legislature. The methods differ in how the quota is determined or, equivalently, how the proportions of votes are rounded off to match the number of seats. The methods of seat allocation can be grouped overall into highest averages methods and largest remainder methods. Largest remainder methods set a particular quota based on the number of voters, while highest averages methods, such as the Sainte-Laguë method and the d'Hondt method, determine the quota indirectly by dividing the number of votes the parties receive by a sequence of numbers. Independently of the method used to assign seats, party-list systems can be open list or closed list. In an open list system, voters decide which candidates within a party win the seats. In a closed list system, the seats are assigned to candidates in a fixed order that the party chooses. The Mixed Member Proportional system is a mixed method that only uses a party list for a subset of the winners, filling other seats with the winners of regional elections, thus having features of open list and closed list systems. In contrast to party-list systems, the single transferable vote (STV) is a proportional representation system in which voters rank individual candidates in order of preference. Unlike party-list systems, STV does not depend on the candidates being grouped into political parties. Votes are transferred between eliminated candidates in a manner similar to instant runoff voting, but in addition to transferring votes from candidates who are eliminated, excess votes are also transferred from candidates who already have a quota. If no excess votes are transferred, but instead the count stops when there are only as many candidates remaining as seats, this system can be considered to be a multimember version of instant runoff voting; such a system has apparently been used in South Australia, where it was known as Bottoms-Up preferential voting.[3] Different proportional representation systems use different geographic divisions. In some party-list or STV systems, all representatives are elected at large, with votes that may come from anywhere in the electorate. In others, the larger area is divided up into multimember districts, causing a trade-off between greater proportional accuracy for larger districts and greater geographical specificity for smaller districts. The mixed member proportional system, mentioned above, has some district-based winners and some at-large winners. And biproportional apportionment systems can achieve proportionality with districts as small as one member each, because each district result is adjusted by effectively transferring votes between same-party candidates in different districts. Semi-proportional methods[edit] An alternative method called cumulative voting (CV) is a semi-proportional voting system in which each voter has n votes, where n is the number of seats to be elected (or, in some potential variants, a different number, e.g. 6 votes for each voter where there are 3 seats). Voters can distribute portions of their vote between a set of candidates, fully upon one candidate, or a mixture. It is considered a proportional system in allowing a united coalition representing a m/(n+1) fraction of the voters to be guaranteed to elect m seats of an n-seat election. For example in a 3-seat election, 3/4 of the voters (if united on 3 candidates) can guarantee control over all three seats. (In contrast, plurality at large allows a united coalition (majority) (50%+1) to control all the seats.) Cumulative voting is a common way of holding elections in which the voters have unequal voting power, such as in corporate governance under the "one share, one vote" rule. Cumulative voting is also used as a multiple-winner method, such as in elections for a corporate board. Cumulative voting is not fully proportional because it suffers from the same spoiler effect of the plurality voting system without a run-off process. A group of like-minded voters divided among "too many" candidates may fail to elect any winners, or elect fewer than they deserve by their size. The level of proportionality depends on how well-coordinated the voters are. Limited voting is a multi-winner system that gives voters fewer votes than the number of seats to be decided. The simplest and most common form of limited voting is single non-transferable vote (SNTV). It can be considered a special variation of cumulative voting where a full vote cannot be divided among more than one candidate. It depends on a statistical distribution of voters to smooth out preferences that CV can do by individual voters. For example, in a 4-seat election a candidate needs 20% to guarantee election. In this case a coalition of 40% of voters can obtain 2 of the 4 seats by splitting their votes as individuals equally between 2 candidates. In comparison, SNTV tends towards collectively dividing 20% between each candidate by assuming every coalition voter flipped a coin to decide which candidate to support with their single vote. This limitation simplifies voting and counting, at the cost of more uncertainty of results. Majoritarian methods[edit] Many multiple-winner voting methods are simple extensions of single-winner methods, without an explicit goal of producing a proportional result. Bloc voting, or plurality-at-large, has each voter vote for N options and selects the top N as the winners. Because of their propensity for landslide victories won by a single winning slate of candidates, bloc voting and similar nonproportional methods are called "majoritarian". Single-winner methods[edit] Single-winner systems can be classified based on their ballot type. In one vote systems, a voter picks one choice at a time. In ranked voting systems, each voter ranks the candidates in order of preference. In rated voting systems, voters give a score to each candidate. Single or sequential vote methods[edit] The most prevalent single-winner voting method, by far, is plurality (also called "first-past-the-post", "relative majority", or "winner-take-all"), where each voter votes for one choice, and the choice that receives the most votes wins, even if it receives less than a majority of votes. Runoff methods hold multiple rounds of plurality voting to ensure that the winner is elected by a majority. Top-two runoff voting, the second most common method used in elections, holds a runoff election between the two highest polling options if there is no absolute majority (above 50%). In elimination runoff elections, the weakest candidate(s) are eliminated until there is a majority. A primary election process is also used as a two round runoff voting system. The two candidates or choices with the most votes in the open primary ballot progress to the general election. The difference between a runoff and an open primary is that a winner is never chosen in the primary, while the first round of a runoff can result in a winner if one candidate has over 50% of the vote. In the Random ballot method, each voter votes for one option and a single ballot is selected at random to determine the winner. This is mostly used as a tiebreaker for other methods. Ranked voting methods[edit] Also known as preferential voting methods, these methods allow each voter to rank the candidates in order of preference. Often it is not necessary to rank all the candidates: unranked candidates are usually considered to be tied for last place. Some ranked ballot methods also allow voters to give multiple candidates the same ranking. The most common ranked voting method is instant-runoff voting (IRV), also known as the "alternative vote" or simply preferential voting, which uses voters' preferences to simulate an elimination runoff election without multiple voting events. As the votes are tallied, the option with the fewest first-choice votes is eliminated. In successive rounds of counting, the next preferred choice still available from each eliminated ballot is transferred to candidates not yet eliminated. The least preferred option is eliminated in each round of counting until there is a majority winner, with all ballots being considered in every round of counting. The Borda count is a simple ranked voting method in which the options receive points based on their position on each ballot. A class of similar methods is called positional voting systems. Other ranked methods include Coombs' method, Supplementary voting, Bucklin voting, and Condorcet method. Condorcet methods, or pairwise methods, are a class of ranked voting methods that meet the Condorcet criterion. These methods compare every option pairwise with every other option, one at a time, and an option that defeats every other option is the Condorcet winner sometimes called the pairwise champion. An option defeats another option if more voters rank the first option higher on their ballot than the number of voters who rank the second option higher. This is called a pairwise defeat. These methods are often referred to collectively as Condorcet methods because the Condorcet criterion ensures that they all give the same result in most elections, where there exists a Condorcet winner. The differences between Condorcet methods occur in situations where no option is undefeated, implying that there exists a cycle of options that defeat one another, called a Condorcet paradox or Smith set. Considering a generic Condorcet method to be an abstract method that does not resolve these cycles, specific versions of Condorcet that select winners even when no Condorcet winner exists are called Condorcet completion methods. A simple version of Condorcet is Minimax: if no option is undefeated, the option that is defeated by the fewest votes in its worst defeat wins. Another simple method is Copeland's method, in which the winner is the option that wins the most pairwise contests, as in many round-robin tournaments. The Kemeny-Young method, the Schulze method (also known as "Schwartz sequential dropping", "cloneproof Schwartz sequential dropping" or the "beatpath method") and Ranked pairs are recently designed Condorcet methods that satisfy a large number of voting system criteria. These three Condorcet methods either fully rank, or can be used to fully rank, all the candidates from most popular to least popular. Rated voting methods[edit] Rated ballots allow even more flexibility than ranked ballots. Each voter gives a score to each option; the allowable scores could be numeric (for example, from 0 to 100) or could be "grades" like A/B/C/D/F. Rated ballots can be used for ranked voting methods, as long as the ranked method allows tied rankings. Some ranked methods assume that all the rankings on a ballot are distinct, but many voters would be likely to give multiple candidates the same rating on a rated ballot. In range voting, voters score or rate each option on a range, and the option with the highest total or average score wins. In majority judgment, similar ballots are used, but the winner is the candidate with the highest median score. Approval voting, where voters may vote for as many candidates as they like, can be seen as an instance of range voting (or majority judgment) where the allowable ratings are 0 and 1. It has recently been studied by, among others, Brams[4] who notes that 'The chief reason for its nonadoption in public elections, and by some societies, seems to be a lack of key "insider" support.' There are variants within cumulative voting. In the points form, each voter has as many votes as there are choices, and can distribute those votes as desired: all on one choice or spread in any other pattern. Cumulative voting is used in a number of communities as well as corporate boards. It was examined and developed perhaps most thoroughly by Lani Guinier (1994). Evaluating voting systems using criteria[edit] In the real world, attitudes toward voting systems are highly influenced by the systems' impact on groups that one supports or opposes. This can make the objective comparison of voting systems difficult. There are several ways to address this problem. Criteria can be defined mathematically, such that any voting system either passes or fails. This gives perfectly objective results, but their practical relevance is still arguable. Another approach is to define ideal criteria that no voting system passes perfectly, and then see how often or how close to passing various systems are over a large sample of simulated elections. This gives results which are practically relevant, but the method of generating the sample of simulated elections can still be arguably biased. A final approach is to create imprecisely defined criteria, and then assign a neutral body to evaluate each system according to these criteria. This approach can look at aspects of voting systems which the other two approaches miss, but both the definitions of these criteria and the evaluations of the methods are still inevitably subjective. Mathematical criteria[edit] To compare systems fairly and independently of political ideologies, voting theorists use voting system criteria, which define potentially desirable properties of voting systems mathematically. Using criteria to compare systems does not make the comparison completely objective. For example, it is relatively easy to devise a criterion that is met by one's preferred voting method, and by very few other methods. Doing this, one can then construct a biased argument for the criterion, instead of arguing directly for the method. There is no ultimate authority on which criteria should be considered, but the following are some criteria that usefully distinguish between various systems and are considered to be desirable by many voting theorists: - Result criteria (absolute) - These are criteria that state that, if the set of ballots is a certain way, a certain candidate must or must not win. - Majority criterion (MC)— Will a candidate always win who is ranked as the unique favorite by a majority of voters? This criterion comes in two versions: - Ranked majority criterion, in which an option which is merely preferred over the others by a majority must win. (Passing the ranked MC is denoted by "yes", because implies also passing the following:) - Rated majority criterion, in which only an option which is uniquely given a perfect rating by a majority must win. The ranked and rated MC are synonymous for ranked voting systems, but not for rated or graded ones. The ranked MC, but not the rated MC, is incompatible with the IIA criterion explained below. - Mutual majority criterion (MMC)— Will a candidate always win who is among a group of candidates ranked above all others by a majority of voters? This also implies the Majority loser criterion—if a majority of voters prefers every other candidate over a given candidate, then does that candidate not win? Therefore, of the systems listed, all pass neither or both criteria, except for Borda, which passes Majority Loser while failing Mutual Majority. - Condorcet criterion— Will a candidate always win who beats every other candidate in pairwise comparisons? (This implies the majority criterion, above) - Condorcet loser criterion (Cond. loser)— Will a candidate always win who is not the candidate who loses to every other candidate in pairwise comparisons? - Result criteria (relative) - These are criteria that state that, if a certain candidate wins in one circumstance, the same candidate must (or must not) win in a related circumstance. - Independence of Smith-dominated alternatives (ISDA)— Does the outcome never change if a Smith-dominated candidate is added or removed (assuming votes regarding the other candidates are unchanged)? Candidate C is Smith-dominated if there is some other candidate A such that C is beaten by A and every candidate B that is not beaten by A etc. Note that although this criterion is classed here as nominee-relative, it has a strong absolute component in excluding Smith-dominated candidates from winning. In fact, it implies all of the absolute criteria above. - Independence of Irrelevant Alternatives (IIA)— Does the outcome never change if a non-winning candidate is added or removed (assuming votes regarding the other candidates are unchanged)?[5] For instance, plurality rule fails IIA; adding a candidate X can cause the winner to change from W to Y even though Y receives no more votes than before. - Local Independence of Irrelevant Alternatives (LIIA)— Does the outcome never change if the alternative that would finish last is removed? (And could the alternative that finishes second fail to become the winner if the winner were removed?) - Independence of Clone Alternatives (Cloneproof)— Does the outcome never change if non-winning candidates similar to an existing candidate are added? There are three different phenomena which could cause a system to fail this criterion: - Spoilers are candidates which decrease the chance of any of the similar or clone candidates winning, also known as a spoiler effect. - Teams are sets of similar candidates whose mere presence helps the chances of any of them winning. - Crowds are additional candidates who affect the outcome of an election without either helping or harming the chances of their factional group, but instead affecting another group. - Monotonicity criterion (Monotone)— If candidate W wins for one set of ballots, will W still always win if those ballots change to rank W higher? (This also implies that you cannot cause a losing candidate to win by ranking him lower.) - Consistency criterion (CC)— If candidate W wins for one set of ballots, will W still always win if those ballots change by adding another set of ballots where W also wins? - Participation criterion (PC)— Is voting honestly always better than not voting at all? (This is grouped with the distinct but similar Consistency Criterion in the table below.[6]) - Reversal symmetry (Reversal) —If individual preferences of each voter are inverted, does the original winner never win? - Ballot-counting criteria - These are criteria which relate to the process of counting votes and determining a winner. - Polynomial time (Polytime)— Can the winner be calculated in a runtime that is polynomial in the number of candidates and linear in the number of voters? - Resolvable— Can the winner be calculated in almost all cases, without using any random processes such as flipping coins? That is, are exact ties, in which the winner could be one of two or more candidates, vanishingly rare in large elections? - Summability (Summable)— Can the winner be calculated by tallying ballots at each polling station separately and simply adding up the individual tallies? The amount of information necessary for such tallies is expressed as an order function of the number of candidates N. Slower-growing functions such as O(N) or O(N2) make for easier counting, while faster-growing functions such as O(N!) might make it harder to catch fraud by election administrators. - Polynomial time (Polytime)— Can the winner be calculated in a runtime that is polynomial in the number of candidates and linear in the number of voters? - Strategy criteria - These are criteria that relate to a voter's incentive to use certain forms of strategy. They could also be considered as relative result criteria; however, unlike the criteria in that section, these criteria are directly relevant to voters; the fact that a system passes these criteria can simplify the process of figuring out one's optimal strategic vote. - Later-no-harm criterion and Later-no-help criterion— Can voters be sure that adding a later preference to a ballot will not harm or help any candidate already listed? - Favorite betrayal criterion (FBC) — Can voters be sure that they do not need to rank any other candidate above their favorite in order to obtain a result they prefer?[8] Note on terminology: A criterion is said to be "weaker" than another when it is passed by more voting systems. Frequently, this means that the conditions for the criterion to apply are stronger. For instance, the majority criterion (MC) is weaker than the multiple majority criterion (MMC), because it requires that a single candidate, rather than a group of any size, should win. That is, any system which passes the MMC also passes the MC, but not vice versa; while any required winner under the MC must win under the MMC, but not vice versa. Compliance of selected systems (table)[edit] The following table shows which of the above criteria are met by several single-winner systems. NA = not applicable. Experimental criteria[edit] It is possible to simulate large numbers of virtual elections on a computer and see how various voting systems compare in practical terms. Since such investigations are more difficult than simply proving that a given system does or does not satisfy a given mathematical criterion, results are not available for all systems. Also, these results are sensitive to the parameters of the model used to generate virtual elections, which can be biased either deliberately or accidentally. One desirable feature that can be explored in this way is maximum voter satisfaction, called in this context minimum Bayesian regret. Such simulations are sensitive to their assumptions, particularly with regard to voter strategy, but by varying the assumptions they can give repeatable measures that bracket the best and worst cases for a voting system.[9] To date, the only such simulation to compare a wide variety of voting systems was run by a range-voting advocate and was not published in a peer-reviewed journal.[10][11] It found that Range voting consistently scored as either the best system or among the best across the various conditions studied.[12] Another aspect which can be compared through such Monte Carlo simulations is strategic vulnerability. According to the Gibbard-Satterthwaite theorem, no voting system can be immune to strategic manipulation in all cases, but certainly some systems will have this problem more often than others. Balinski and R. Laraki, the inventors of the majority judgment system, performed such an investigation using a set of simulated elections based on the results from a poll of the 2007 French presidential election which they had carried out using rated ballots. Comparing range voting, Borda count, plurality voting, approval voting with two different absolute approval thresholds, Condorcet voting, and majority judgment, they found that range voting had the highest (worst) strategic vulnerability, while their own system majority judgment had the lowest (best).[13] Balinski and Laraki also used the same data to investigate how likely it was that each of those systems, as well as runoff voting, would elect a centrist. Opinions differ on whether this is desirable or not. Some argue that systems which favor centrists are better because they are more stable; others argue that electing ideologically purer candidates gives voters more choice and a better chance to retrospectively judge the relative merits of those ideologies; while Balinski and Laraki argue that both centrist and extremist candidates should have a chance to win, to prevent forcing candidates into taking either position. According to their model, plurality, runoff voting, and approval voting with a higher approval threshold tended to elect extremists (100%, 98%, and 94% of the time, respectively); majority judgement elected both centrists and extremists (56% extremists); and range, Borda, and approval voting with a lower approval threshold elected centrists (6%; 0.25%–13% depending on the number of candidates; and 6% extremists; respectively).[13] However, their model did not take into account voters' strategic reactions to the system used, such as "lesser of two evils" voting under plurality. Simulated elections in a two-dimensional issue space can also be graphed to visually compare election methods; this illustrates issues like nonmonotonicity, clone-independence, and tendency to elect centrists vs extremists.[14] "Soft" criteria[edit] In addition to the above criteria, voting systems are judged using criteria that are not mathematically precise but are still important, such as simplicity, speed of vote-counting, the potential for fraud or disputed results, the opportunity for tactical voting or strategic nomination, and, for multiple-winner methods, the degree of proportionality produced. The New Zealand Royal Commission on the Electoral System listed ten criteria for their evaluation of possible new electoral systems for New Zealand. These included fairness between political parties, effective representation of minority or special interest groups, political integration, effective voter participation and legitimacy. History[edit] Early democracy[edit] Voting has been used as a feature of democracy since the 6th century BC, when democracy was introduced by the Athenian democracy. However, in Athenian democracy, voting was seen as the least democratic among methods used for selecting public officials, and was little used, because elections were believed to inherently favor the wealthy and well-known over average citizens. Viewed as more democratic were assemblies open to all citizens, and selection by lot (known as sortition), as well as rotation of office. One of the earliest recorded elections in Athens was a plurality vote that it was undesirable to "win": in the process called ostracism, voters chose the citizen they most wanted to exile for ten years. Most elections in the early history of democracy were held using plurality voting or some variant, but as an exception, the state of Venice in the 13th century adopted the system we now know as approval voting to elect their Great Council.[15] The Venetians' system for electing the Doge was a particularly convoluted process, consisting of five rounds of drawing lots (sortition) and five rounds of approval voting. By drawing lots, a body of 30 electors was chosen, which was further reduced to nine electors by drawing lots again. An electoral college of nine members elected 40 people by approval voting; those 40 were reduced to form a second electoral college of 12 members by drawing lots again. The second electoral college elected 25 people by approval voting, which were reduced to form a third electoral college of nine members by drawing lots. The third electoral college elected 45 people, which were reduced to form a fourth electoral college of 11 by drawing lots. They in turn elected a final electoral body of 41 members, who ultimately elected the Doge. Despite its complexity, the system had certain desirable properties such as being hard to game and ensuring that the winner reflected the opinions of both majority and minority factions.[16] This process, with slight modifications, was central to the politics of the Republic of Venice throughout its remarkable lifespan of over 500 years, from 1268 to 1797. Foundations of voting theory[edit] Voting theory became an object of academic study around the time of the French Revolution.[15] Jean-Charles de Borda proposed the Borda count in 1770 as a method for electing members to the French Academy of Sciences. His system was opposed by the Marquis de Condorcet, who proposed instead the method of pairwise comparison that he had devised. Implementations of this method are known as Condorcet methods. He also wrote about the Condorcet paradox, which he called the intransitivity of majority preferences.[17] While Condorcet and Borda are usually credited as the founders of voting theory, recent research has shown that the philosopher Ramon Llull discovered both the Borda count and a pairwise method that satisfied the Condorcet criterion in the 13th century. The manuscripts in which he described these methods had been lost to history until they were rediscovered in 2001.[18] Later in the 18th century, the related topic of apportionment began to be studied. The impetus for research into fair apportionment methods came, in fact, from the United States Constitution, which mandated that seats in the United States House of Representatives had to be allocated among the states proportionally to their population, but did not specify how to do so.[19] A variety of methods were proposed by statesmen such as Alexander Hamilton, Thomas Jefferson, and Daniel Webster. Some of the apportionment methods discovered in the United States were in a sense rediscovered in Europe in the 19th century, as seat allocation methods for the newly proposed system of party-list proportional representation. The result is that many apportionment methods have two names: for instance, Jefferson's method is equivalent to the d'Hondt method, as is Webster's method to the Sainte-Laguë method, while Hamilton's method is identical to the Hare largest remainder method.[19] The Single Transferable Vote system was devised by Carl Andrae in Denmark in 1855, and also in England by Thomas Hare in 1857. Their discoveries may or may not have been independent. STV elections were first held in Denmark in 1856, and in Tasmania in 1896 after its use was promoted by Andrew Inglis Clark. Party-list proportional representation was first implemented to elect European legislatures in the early 20th century, with Belgium implementing it first in 1899. Since then, proportional and semi-proportional methods have come to be used in almost all democratic countries, with most exceptions being former British colonies.[20] Single-winner revival[edit] Perhaps influenced by the rapid development of multiple-winner voting methods, theorists began to publish new findings about single-winner methods in the late 19th century. This began around 1870, when William Robert Ware proposed applying STV to single-winner elections, yielding instant runoff voting.[21] Soon, mathematicians began to revisit Condorcet's ideas and invent new methods for Condorcet completion. Edward J. Nanson combined the newly described instant runoff voting with the Borda count to yield a new Condorcet method called Nanson's method. Charles Dodgson, better known as Lewis Carroll, published pamphlets on voting theory, focusing in particular on Condorcet voting. He introduced the use of matrices to analyze Condorcet elections, though this, too, had already been done in some form in the then-lost manuscripts of Ramon Llull. He also proposed the straightforward Condorcet method known as Dodgson's method as well as a proportional multiwinner method based on proxy voting. Ranked voting systems eventually gathered enough support to be adopted for use in government elections. In Australia, IRV was first adopted in 1893, and continues to be used along with STV today. In the United States in the early-20th-century Progressive era, various municipalities began to use Bucklin voting. Bucklin is no longer used in any government elections, and has even been declared unconstitutional in Minnesota.[22] Influence of game theory[edit] After John von Neumann and others developed the mathematical field of game theory in the 1940s, new mathematical tools were available to analyze voting systems and strategic voting. One such tool was the idea of a strong Nash equilibrium, based on the work of John Nash in the 1950s. This and similar methods led to significant new results that changed the field of voting theory.[15][need quotation to verify] The use of mathematical criteria to evaluate voting systems was introduced when Kenneth Arrow showed in Arrow's impossibility theorem that certain intuitively desirable criteria were actually mutually contradictory, demonstrating the inherent limitations of voting theorems. Among the criteria Arrow considered desirable was one which requires the voting system to use ordinal (ranking) information; thus, as John Harsanyi pointed out, cardinal (rated) voting systems such as approval voting, range voting, and majority judgment can successfully meet all the other criteria. Arrow's theorem is easily the single most cited result in voting theory, and it inspired further significant results such as the Gibbard-Satterthwaite theorem, which showed that strategic voting is unavoidable in certain common circumstances, for any deterministic voting system, whether cardinal or ordinal. The use of game theory to analyze voting systems also led to discoveries about the emergent strategic effects of certain systems. Duverger's law is a prominent example of such a result, showing that plurality voting often leads to a two-party system. Further research into this and other game theory aspects of voting led Steven Brams and Peter Fishburn to formally define and promote the use of approval voting in 1977. While approval voting had been used before that, it had not been named or considered as an object of academic study, particularly because it violated the assumption made by most research that single-winner methods were based on ordinal preference rankings.[23] Public choice theory, a field which uses economic modeling tools including game theory to study the behavior of politicians and voters, began to form in the 1950s, and was both influenced by and influential on voting theory. Post-1980 developments[edit] Voting theory has come to focus on voting system criteria almost as much as it does on particular voting systems. Now, any description of a benefit or weakness in a voting system is expected to be backed up by a mathematically defined criterion. Recent research in voting theory has largely involved devising new criteria and new methods devised to meet certain criteria. By contrast, the factors driving voters to accept or reject particular systems in elections tend to be based on other arguments. Political scientists of the 20th century published many studies on the effects that the voting systems have on voters' choices and political parties,[24][25][26] and on political stability.[27][28] A few scholars also studied what effects caused a nation to change for a particular voting system.[29][30][31][32][33] One prominent current voting theorist is Nicolaus Tideman, who formalized concepts such as strategic nomination and the spoiler effect in the independence of clones criterion. Tideman also devised the ranked pairs method, a Condorcet method that is not susceptible to clones. Also, Donald G. Saari has brought renewed interest to the Borda count with the books he has published since 2001. Saari uses geometric models of positional voting systems to promote the Borda count. The increased availability of computer processing has increased the practicality of using the Kemeny-Young, ranked pairs, and Schulze methods that fully rank all the choices from most popular to least popular. The advent of the Internet has increased the interest in voting systems. Unlike many mathematical fields, voting theory is generally accessible enough to non-experts that new results can be discovered by amateurs, and frequently are. The study of voting systems has influenced a new push for electoral reform beginning around the 1990s, with proposals being made to replace plurality voting in governmental elections with other methods. New Zealand adopted Mixed Member Proportional for Parliamentary elections in 1993 and Single Transferable Vote for some local elections in 2004 (see Electoral reform in New Zealand). After plurality voting was a key factor in the contested results of the 2000 US presidential election, various municipalities in the United States began to adopt instant-runoff voting, although some of them subsequently returned to their prior system. The Canadian province of British Columbia held two unsuccessful referendums (in 2005 and 2009) to adopt an STV system, and Ontario, another Canadian province, held an unsuccessful referendum on October 10, 2007 on whether to adopt a Mixed Member Proportional system. An even wider range of voting systems is now seen in non-governmental organizations. Though theorists are divided on which particular voting system is best, many agree that several options are superior to plurality. For instance, the "Declaration of Election-Method Reform Advocates" supports single-winner reforms including approval voting, various Condorcet methods, majority judgment, and range voting.[34][35] It has been argued that more in-depth and fine-tuned voting systems lie at the core of the development of e-democracy,[36] which consists of the digitization of democratic processes, including voting.[37] Research is ongoing into the use of homomorphic encryption for making voting systems that are transparent and voter-verifiable without compromising ballot secrecy. Tough criteria have been published for this [1] and some advocates consider them to have been met for instance in Norway [2] or Estonia [3] - the latter even published its source code online, allowing independent verification at least of the voting-specific code. However, as of November 2014, the majority of legal and political analysts stand firmly against computerized voting [4][5][6][], and argue that only paper ballots (whether machine-printed and voter-verified, or even exclusively hand-marked) give a reliable audit trail. Perhaps more importantly, they argue that important protections of electoral neutrality and perceived fairness can never be provided in an online voting context: - Scrutineers from each political party cannot inspect the process as it occurs in every location - Polling place neutrality is impossible to guarantee, especially in the last instants before vote casting - a popup containing false information, for instance, can appear just as a ballot is cast - Ordinary persons can neither understand nor be trained to participate in the counting process, which may be particularly important in recounts or disputes. - The complexity of underlying hardware, networks, operating systems, and incidental software is such that mass peer review is always inadequate to fend off voting disputes. For instance, the New Brunswick general election, 2014, stalled reporting of electronic vote counts cast doubt on the results and led to demands for a general recount [7] - impossible without paper ballots. Alongside these proposed and mostly unsuccessful reforms, other types of electoral and mass decision reform succeeded. For instance the rise of disapproval voting in the form of recall elections and referendums on matters that previously would have been left to the decision of a general election or legislature. California elected Arnold Schwarzenegger in a widely contested recall election. Many US states held referenda to specifically disapprove of same-sex marriage, though some of these were later overturned by the courts. And the rise of third parties and minority governments in the British Commonwealth led to several minority governments, coalitions and "hung parliaments" and thus an increase in votes of no confidence causing early elections. Despite many mathematical, political and legal arguments against unadvertised coalitions, 130-candidate first-past-the-post elections as in California, or referenda on what some regard as basic human rights, these measures went ahead anyway, often with results that did not reflect the expectations or traditions of the electoral or party system that was challenged: - While UK Liberal-Democrats had campaigned largely "to the left" of the UK Labour Party, their coalition with the Conservatives forced them to support unadvertised right wing economic measures - While nominally a Republican, Arnold Schwarzenegger's cabinet and advisors consisted largely of Democrats connected to his wife Maria Shriver of the notable Democrat Kennedy family, and his policy measures (notably on energy, transport, climate) differed markedly from the federal GOP - Representatives recalled were often re-elected in the general election when there was less money and attention paid to their seat specifically Also significant since 1980 is actual experience with voting system referenda and change. As noted above, several US cities adopted instant-runoff voting, and a few discarded it after non-monotonic results. Post-facto analysis of six failed electoral referenda in Canada [8][9][10] and nationwide reform in the UK [11] yielded no consensus about voting system criteria that the public actually applied or expected to be applied to evaluate new systems. The only consensus seemed to be that change is difficult against any active "No" campaign that seeks to preserve the status quo, particularly if it can exploit distrust of political parties. See also[edit] - Issue voting - Nakamura number - Opinion poll - Proxy voting - Table of voting systems by country - Comparison of voting systems - Vote counting system - Voting machine - Duverger's law - Micromega rule - Experimental political science - Leader election Criteria table notes[edit] - ^ Approval fails the majority criterion because it does not always elect a candidate preferred by over half of voters; however, it always elects the candidate approved by the most voters. - ^ a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac ad ae af ag ah ai aj ak al am an ao ap Condorcet, Smith and Independence of Smith-dominated alternatives criteria are incompatible with Independence of irrelevant alternatives, Consistency, Participation, Later-no-harm and Favorite betrayal criteria. - ^ a b c In Approval, Range, and Majority Judgment, if all voters have perfect information about each other's true preferences and use rational strategy, any Majority Condorcet or Majority winner will be strategically forced – that is, win in all of one or more strong Nash equilibria. In particular if every voter knows that "A or B are the two most-likely to win" and places their "approval threshold" between the two, then the Condorcet winner, if one exists and is in the set {A,B}, will always win. These systems also satisfy the majority criterion in the weaker sense that any majority can force their candidate to win, if it so desires. Laslier, J-F (2006), "Strategic approval voting in a large electorate", IDEP Working Papers (Marseille, France: Institut D'Economie Publique) (405). - ^ a b c Approval voting, range voting, and majority judgement satisfy IIA if it is assumed that voters rate candidates individually and independently of knowing the available alternatives in the election, using their own absolute scale. For this to hold, in some elections, some voters must use less than their full voting power or even effectively abstain, despite having meaningful preferences among the available alternatives. If this assumption is not made, these systems fail IIA. - ^ The original Independence of clones criterion applied only to ranked voting methods. Nicolaus Tideman, "Independence of clones as a criterion for voting rules", Social Choice and Welfare Vol. Tideman notes that "in the spirit of independence of clones", "if there were two or more candidates who were so similar that every voter would rank them as tied if given the chance to rank them [...], then the number of perfect clones present would have no effect on whether the perfect clones were in the set of winning candidates under approval voting". So, Approval Voting satisfies this mathematical criterion by definition. However, there is some disagreement about whether considerations of the voter in the process of making up his vote could be tactically influenced by clones (in a way that a voter would dispossess a candidate of his approval when a clone of him is introduced) and whether the definition of clones have to be extended to these considerations additionally to the handling of actual votes. - ^ Later-No-Harm and Later-No-Help assert that adding a later preference to a strictly ordered preference ballot should not help or harm an earlier preference. An Approval ballot records approvals but does not record explicit relative (e.g. later) preferences between approvals (while preferences exist from a voter’s perspective). Meanwhile, a voter approving a less preferred candidate harms the probability of any other approved candidate winning, but does not help. - ^ The number of piles that can be summed from various precincts is floor ((e−1) N!) - ^ Kemeny-Young does not pass the consistency criterion for winner, but the consistency criterion for full rankings, that is, if the electorate is divided in two parts and in both parts Kemeny-Young chooses the same ranking, Kemeny-Young will also choose that ranking for the combined electorate. - ^ Each prospective Kemeny-Young ordering has score equal to the sum of the pairwise entries that agree with it, and so the best ordering can be found using the pairwise matrix. - ^ Bucklin voting, with skipped and equal-rankings allowed, meets the same criteria as Majority Judgment; in fact, Majority Judgment may be considered a form of Bucklin voting. Without allowing equal rankings, Bucklin's criteria compliance is worse; in particular, it fails Independence of Irrelevant Alternatives, which for a ranked method like this variant is incompatible with the Majority Criterion. - ^ Majority Judgment fails the majority criterion because it does not always elect a candidate preferred by over half of voters; however, it always elects the candidate uniquely top-rated by over half of voters. - ^ Majority Judgment fails the mutual majority criterion, but satisfies the criterion if the majority ranks the mutually favored set above a given absolute grade and all others below that grade. - ^ Balinski and Laraki, Majority Judgment's inventors, point out that it meets a weaker criterion they call "grade consistency": if two electorates give the same rating for a candidate, then so will the combined electorate. Majority Judgment explicitly requires that ratings be expressed in a "common language", that is, that each rating have an absolute meaning. They claim that this is what makes "grade consistency" significant. Balinski M, MJ; Laraki, R (2007), Proceedings 104 (21), USA: National Academy of Sciences, pp. 8720–25. - ^ a b c In Majority Judgment, Ranked Pairs, and Sculze voting, there is always a regret-free semi-honest ballot for any voter, holding other ballots constant. That is, if they know enough about how others will vote (for instance, in the case of Majority Judgment, the winning candidate and their winning median score), there is always at least way for them to participate without grading any less-preferred candidate above any more-preferred one. However, the systems can fail the participation criterion if voters have insufficient information. - ^ Majority judgment can actually pass or fail reversal symmetry depending on the rounding method used to find the median when there are even numbers of voters. For instance, in a two-candidate, two-voter race, if the ratings are converted to numbers and the two central ratings are averaged, then MJ meets reversal symmetry; but if the lower one is taken, it does not, because a candidate with ["fair","fair"] would beat a candidate with ["good","poor"] with or without reversal. However, for rounding methods which do not meet reversal symmetry, the odds of breaking it are comparable to the odds of an irresolvable (tied) result; that is, vanishingly small for large numbers of voters. - ^ Majority Judgment is summable at order KN, where K, the number of ranking categories, is set beforehand. - ^ In fact, Majority Judgment ballots use ratings expressed in "common language" rather than numbers, that is, that each rating have an absolute meaning. - ^ Though Majority Judgment does not pass this or similar criteria, there are other similar median systems, such as those based on Bucklin voting, which can meet a related, weaker criterion: ranking an additional candidate below the median grade (rather than your own grade) of your favorite candidate, cannot harm your favorite. Balinski, M., and R. Laraki. “A Theory of Measuring, Electing, and Ranking.” Proceedings of the National Academy of Sciences 104, no. 21 (2007): 8720. - ^ a b A variant of Minimax that counts only pairwise opposition, not opposition minus support, fails the Condorcet criterion and meets later-no-harm. - ^ a b Since plurality does not allow marking later preferences on the ballot at all, it is impossible to either harm or help a favorite candidate by marking later preferences, and so it trivially passes both Later-No-Harm and Later-No-Help. However, because it forces truncation, it shares some problems with systems that merely encourage truncation by failing Later-No-Harm. Similarly, though to a lesser degree, because it doesn't allow voters to distinguish between all but one of the candidates, it shares some problems with methods which fail Later-No-Help, which encourage voters to make such distinctions dishonestly. - ^ Once for each round. - ^ Once for each round. - ^ Later preferences are only possible between the two candidates who make it to the second round. - ^ That is, second-round votes cannot help or harm candidates already eliminated. - ^ Random winner: Uniformly randomly chosen candidate is winner. Arbitrary winner: some external entity, not a voter, chooses the winner. These systems are not, properly speaking, voting systems at all, but are included to show that even a horrible system can still pass some of the criteria. - ^ Random ballot: Uniformly random-chosen ballot determines winner. This and closely related systems are of mathematical interest because they are the only possible systems which are truly strategy-free, that is, your best vote will never depend on anything about the other voters. However, this system is not generally considered as a serious proposal for a practical method. References[edit] Bibliography[edit] - Arrow, Kenneth J (1963) [1951], Social Choice and Individual Values (2nd ed.), New Haven: Yale University Press, ISBN 0-300-01364-7. - Balinski, M; Laraki, R (2007), "Election by Majority Judgement: Experimental Evidence", Cahier du Laboratoire d’Econométrie de l’Ecole Polytechnique (28) - Balinski, M; Laraki, R (2011), "Election by Majority Judgement: Experimental Evidence", in Dolez, Bernard; Grofman, Bernard; Laurent, Annie, In Situ and Laboratory Experiments on Electoral Law Reform: French Presidential Elections, Springer. - Boix, Carles (1999). "Setting the Rules of the Game: The Choice of Electoral Systems in Advanced Democracies". American Political Science Review 93 (3): 609–24. - Colomer, Josep M., ed. Handbook of Electoral System Choice. London and New York: Palgrave Macmillan. - Cranor, Lorrie. "Vote Aggregation Methods". Declared-Strategy Voting: An Instrument for Group Decision-Making. Retrieved October 3, 2005. - Emerson, Peter, Defining Democracy, publisher=Springer, 2012, isbn 978-3-642-20903-1 - Farrell, David M. (2001). Electoral Systems: A Comparative Introduction. New York: St. Martin's Press. - Dummett, Michael (1997). Principles of Electoral Reform. New York: Oxford University Press. - Duverger, Maurice (1954). Political Parties. New York: Wiley. - Hermens, Ferdinand A. (1941). "Democracy or Anarchy? A Study of Proportional Representation". Notre Dame, Indiana: University of Notre Dame. - Lijphart, Arend - Lijphart, Arend (1985). "The Field of Electoral Systems Research: A Critical Survey". Electoral Studies 4. - Lijphart, Arend (1992). "Democratization and Constitutional Choices in Czecho-Slovakia, Hungary and Poland, 1989–1991". Journal of Theoretical Politics 4 (2): 207–23. - Lijphart, Arend (1994). Electoral Systems and Party Systems: A Study of Twenty-Seven Democracies, 1945–1990. Oxford: Oxford University Press. - Owen, Bernard (2002), Le système électoral et son effet sur la représentation parlementaire des partis: le cas européen (in French), LGDJ. - Poundstone, William (2008), Gaming the Vote: Why Elections Aren't Fair (and What We Can Do About It), New York: Hill and Young. - Rae, Douglas W (1971). The Political Consequences of Electoral Laws. New Haven: Yale University Press. - Reynolds, Andrew, Reilly, Benjamin and Ellis, Andrew, The New International IDEA Handbook of Electoral System Design, International IDEA, Stockholm 2005. - Rogowski, Ronald (1987). "Trade and the Variety of Democratic Institutions" 41. International Organization. - Rokkan, Stein (1970). "Citizens, Elections, Parties: Approaches to the Comparative Study of the Process of Development". Oslo: Universitetsforlaget. - Taagapera, Rein; Shugart, Matthew S. (1989). Seats and Votes: The Effects and Determinants of Electoral Systems. New Haven: Yale University Press. Remission[edit] - ^ Ludwig Windthorst, Speech in Favor of Reforming the Prussian Suffrage, in the Prussian House of Deputies, 26 November 1873 - ^ Douglas J. Amy, "How proportional representation elections work", PR Library - ^ "Bottoms-Up" preferential voting use in Australia - ^ Brams (2003), Theory to practice (PDF), New York city, NY, USA: NYU. - ^ Vasiljev, Sergei (April 1, 2008), Cardinal Voting: The Way to Escape the Social Choice Impossibility, SSRN eLibrary. Note that in practice, voters could change their votes depending on who is in the race (especially in cardinal voting systems). However, this possibility is ignored, because if it were accounted for, no deterministic system could possibly pass this criterion. - ^ Consistency implies participation, but not vice versa. For example, range voting complies with participation and consistency, but median ratings satisfies participation and fails consistency. - ^ Woodall, Douglas (December 1994), "Properties of Preferential Election Rules", Voting Matters (3). - ^ Small, Alex (August 22, 2010), "Geometric construction of voting methods that protect voters’ first choices", arXiv (1008.4331). - ^ Poundstone 2008, p. 239. - ^ WDS, "Appendix", Range vote (PDF) (unpublished paper), Temple. - ^ Poundstone 2008, p. 257: ‘Range voting is still largely a samizdat enterprise on the fringes of social choice theory. The most glaring example must be Smith's pivotal 2000 paper. It has never been published in a journal.’ - ^ Poundstone 2008, p. 240. - ^ a b Balinski & Laraki 2007. - ^ These two-dimensional graphs are called Yee diagrams after their inventor, Ka-Ping Yee. His website includes some sample graphs. - ^ a b c J. J. O'Connor and E. F. Robertson. "The history of voting". The MacTutor History of Mathematics Archive. Retrieved October 12, 2005. - ^ Mowbray, Miranda; Gollmann, Dieter. "Electing the Doge of Venice: Analysis of a 13th Century Protocol". Retrieved July 12, 2007. - ^ O'Connor, JJ; Robertson, EF. "Marie Jean Antoine Nicolas de Caritat Condorcet". The MacTutor History of Mathematics Archive. Retrieved October 12, 2005. - ^ Hägele, G; Pukelsheim, F (2001). "Llull's writings on electoral systems". Studia Lulliana 3: 3–38. - ^ a b Joseph Malkevitch. "Apportionment". AMS Feature Columns. Retrieved October 13, 2005. - ^ "Proportional Voting Around the World". FairVote.org. Retrieved October 13, 2005. - ^ "The History of IRV". FairVote.org. Retrieved November 9, 2005. - ^ Tony Anderson Solgård and Paul Landskroener. "Municipal Voting System Reform: Overcoming the Legal Obstacles". Bench & Bar of Minnesota. Retrieved November 16, 2005. - ^ Poundstone 2008, p. 198. - ^ Duverger 1954. - ^ Taagapera & Shugart 1989. - ^ Hermens 1941. - ^ Lijphart 1994. - ^ Lijphart 1985. - ^ Lijphart 1992. - ^ Rokkan 1970. - ^ Rogowski 1987. - ^ Quinn, Jameson; Fobes, Richard. "Declaration of Election-Method Reform Advocates". Retrieved April 22, 2012. - ^ Tawfik, Adrian; Fobes, Richard (April 22, 2012). "Democracy Chronicles Interviews Election Experts". Democracy Chronicles. Retrieved April 22, 2012. - ^ Martin Hilbert (April 2009). "The Maturing Concept of E-Democracy: From E-Voting and Online Consultations to Democratic Value Out of Jumbled Online Chatter". Journal of Information Technology and Politics. Retrieved February 24, 2010. - ^ Hilbert, Martin (2007), Digital Processes & Democratic Theory: Dynamics, risks and opportunities that arise when democratic institutions meet digital information and communication technologies. External links[edit] - Existing electoral systems and related practical considerations - Handbook of Electoral System Choice - ACE Electoral Knowledge Network Site on electoral systems and management - A handbook of electoral system Design (Only covers systems currently in use at the national level of some country.) - The de Borda Institute - Electoral system reform advocacy - Proportional Representation Society of Australia Electoral reform NGO - The Center for Election Science - Center for Range Voting - Center for Voting and Democracy Advocates using IRV in the United States. - Electoral Reform Society - Pushing to reform democracy in the United Kingdom - Declaration of Election-Method Reform Advocates - Theoretical resources - Accurate Democracy: electoral and legislative voting rules - Electowiki A wiki that focuses on voting theory - VoteRoll is a vote blog roll system developing statistics for people voting online. - OpenSTV Software for computing a variety of voting systems including IRV, STV, and Condorcet. - Student's Social Choice by Alex Bogomolny. Illustrates various concepts of choice using Java applets. - Voting and Election Reform: election calculator and other resources - Math in Society chapter: Voting Theory - Voting Systems by Paul E. Johnson. A textbook-style overview of voting methods and their mathematical properties. - Practical multi-candidate election system