No ranked-preference method can meet all of the criteria, because some of them are mutually exclusive, as shown by statements such as Arrow's impossibility theorem and the Gibbard—Satterthwaite theorem. Many of the mathematical criteria by which voting methods are compared were formulated for voters with ordinal preferences.
Plurality systems[ edit ] Countries using first-past-the-post for legislatures. Plurality voting is a system in which the candidate s with the highest amount of vote wins, with no requirement to get a majority of votes. In cases where there is a single position to be filled, it is known as first-past-the-post ; this is the second most common electoral system for national legislatures, with 58 countries using it to elect their legislatures,  the vast majority of which are current or former British or American colonies or territories.
It is also the second most common system used for presidential elections, being used in 19 countries. This is used in five countries as part of mixed systems. First preference votes are counted as whole numbers; the second preference votes divided by two, third preferences by three; this continues to the lowest possible ranking.
There are two main forms of majoritarian systems, one using a single round of ranked voting and the other using two or more rounds. Both are primarily used for single-member constituencies.
Majoritarian voting can take place in a single round using instant-runoff voting IRVwhereby voters rank candidates in order of preference; this system is used for parliamentary elections in Australia and Papua New Guinea.
If no candidate receives a majority of the vote in the first round, the second preferences of the lowest-ranked candidate are then added to the totals. If not all voters use all their preference votes, then the count may continue until two candidates remain, at which point the winner is the one with the most votes.
A modified form of IRV is the contingent vote where voters do not rank all candidates, but have a limited number of preference votes.
If no candidate has a majority in the first round, all candidates are excluded except the top two, with the highest remaining preference votes from the votes for the excluded candidates then added to the totals to determine the winner.
This system is used in Sri Lankan presidential elections, with voters allowed to give three preferences. It is also used in 20 countries for electing the legislature. In most cases the second round is limited to the top two candidates from the first round, although in some elections more than two candidates may choose to contest the second round; in these cases the second round is decided by plurality voting.
An exhaustive ballot is not limited to two rounds, but sees the last-placed candidate eliminated in the round of voting. Due to the large potential number of rounds, this system is not used in any major popular elections, but is used to elect the Speakers of parliament in several countries and members of the Swiss Federal Council.
In some formats there may be multiple rounds held without any candidates being removed until a candidate achieves a majority, a system used in the United States Electoral College.
Proportional systems[ edit ] Countries by type of proportional system Proportional representation is the most widely used electoral system for national legislatures, with the parliaments of over eighty countries elected by various forms of the system.
Party-list proportional representation is the single most common electoral system and is used by 80 countries, and involves voters voting for a list of candidates proposed by a party.
In closed list systems voters do not have any influence over the candidates put forward by the party, but in open list systems voters are able to both vote for the party list and influence the order in which candidates will be assigned seats.
In some countries, notably Israel and the Netherlandselections are carried out using 'pure' proportional representation, with the votes tallied on a national level before assigning seats to parties. However, in most cases several multi-member constituencies are used rather than a single nationwide constituency, giving an element of geographical representation.
However, this can result in the distribution of seats not reflecting the national vote totals. As a result, some countries have leveling seats to award to parties whose seat totals are lower than their proportion of the national vote. In addition to the electoral thresholdthe minimum percentage of the vote that a party must obtain to win seats, there are several different methods for calculating seat allocation in proportional systems, typically broken down into the two main types; highest average and largest remainder.
Under largest remainder systems, party's vote shares are divided by the quota obtained by dividing the number of votes by the number of seats available. This usually leaves some seats unallocated, which are awarded to parties based on the largest fractions of seats that they have remaining.
Examples of largest remainder systems include the Hare quotaDroop quotathe Imperiali quota and the Hagenbach-Bischoff quota. Single transferable vote STV is another form of proportional representation, but is achieved by voters ranking candidates in a multi-member constituency by preference rather than voting for a party list; it is used in Malta and the Republic of Ireland.
To be elected, candidates must pass a quota the Droop quota being the most common. Candidates that pass the quota on the first count are elected.
Votes are then reallocated from the least successful candidates until the number of candidates that have passed the quota is equal to the number of seats to be filled. These include parallel voting and mixed-member proportional representation. In parallel voting systems, which are used in 20 countries,  there are two methods by which members of a legislature are elected; part of the membership is elected by a plurality or majority vote in single-member constituencies and the other part by proportional representation.
The results of the constituency vote has no effect on the outcome of the proportional vote. Variations of this include the Additional Member System and Alternative Vote Plusin which voters rank candidates, and the other from multi-member constituencies elected on a proportional party list basis.
A form of mixed-member proportional representation, Scorporowas used in Italy from until Additional features[ edit ] Some electoral systems feature a majority bonus system to either ensure one party or coalition gains a majority in the legislature, or to give the party receiving the most votes a clear advantage in terms of the number of seats.
In Greece the party receiving the most votes is given an additional 50 seats,  San Marino has a modified two-round system, which sees a second round of voting featuring the top two parties or coalitions if there is no majority in the first round.Your personal portal to access voting location, registration status, ballot info and much more.
eBallot gets you the results you need to make the important decisions. Build your ballot in minutes and notify your voters. Using our online voting system, they’ll . Secure and transparent online voting system. Easy to set up and vote on-the-go. Blockchain based for top-level safety and voting process decentralization.
© Cable News Network. Turner Broadcasting System, Inc. All Rights Reserved. CNN Sans ™ & © Cable News Network. The Department of Elections envisions an electoral process that is trustworthy and accountable at all levels and engages Virginia’s diverse citizenry in the most fundamental right: the right to vote.
Castavote (c) Remember Me Forgotten Details.