Example Instant-runoff voting ballot
'Instant-runoff voting' ('IRV'), also referred to as
preferential voting is a
voting system most commonly used for single member elections in which
voters have one vote, but can rank
candidates in order of preference. In an IRV election, if no candidate receives an
overall majority of first choices, the candidate with the fewest number of votes is excluded, and ballots cast for that candidate are redistributed to the remaining candidates according to the voters' indicated preference. This process is repeated until one candidate obtains a
majority (50% or more) of votes. The term 'instant runoff voting' is used because this process resembles a series of
run-off elections.
At a national level IRV is used to elect the
Australian House of Representatives[1], the
President of Ireland, the national parliament of
Papua New Guinea and the
Fijian House of Representatives. In the United States, it has been adopted in at least ten local jurisdictions, including three large population cities and counties during the
2006 United States general elections. In the United Kingdom, a form of IRV is used to elect the
mayor of London. IRV is recommended by
Robert's Rules of Order for electing officers by mail and is used in many non-governmental elections.
Terminology
Instant runoff voting has been called a number of other names. In the
United States it is called instant runoff voting primarily because of its resemblance to
runoff voting, which is also used in that country and many presidential elections around the world. In the
United Kingdom it is known as the 'Alternative Vote' ('AV'), or as the 'Alternative Transferrable Vote' ('ATV'). In Australia the generic term 'preferential voting' is used (IRV is only one of a number of
preferential voting systems). When used in
Canada in the past it was known as the 'preferential ballot'. It is also sometimes known in the United States as 'ranked choice voting'.
When the
single transferable vote (STV) system is applied to a single-winner election it becomes the same as IRV. For this reason IRV is sometimes considered to be merely a special form of STV. However, because STV was designed for multi-seat
constituencies, many scholars consider it to be a separate system from IRV, and that is the convention followed in this article.
IRV is usually known simply as "STV" in
New Zealand and Ireland, although the term Alternative Vote is also used in those countries. IRV is sometimes referred to as the 'Hare system', after
Thomas Hare, one of the inventors of STV. It has also been referred to as 'Ware's method', after its own inventor,
William Robert Ware. Writers differ as to whether or not they treat ''instant runoff voting'' as a
proper noun.
Voting
In IRV the voter ranks the list of candidates in order of preference. Under the most common
ballot layout, ascending cardinal numbers are used, whereby the voter places a '1' beside their most preferred candidate, a '2' beside their second-most preferred, and so forth. In the ballot paper shown at the top-right of this page, the preferences of the voter are as follows:
#John Citizen
#Mary Hill
#Jane Doe
Each voter casts only one vote, but during the process of counting votes, his or her vote may be redistributed and counted for the next sequential preference allocated to any remaining candidate that has not been earlier excluded from the count.
Counting the votes
In an IRV election, every voter has one vote, but can express more than one choice in order of preference. Ballots are initially sorted according to their expressed first choices. If no candidate achieves an
overall majority of first choices (more than half of the total vote) then the candidate with the lowest number of votes choices is excluded from the count. Ballot papers allocated to excluded candidate's are redistributed and recounted to the remaining candidates according to the expressed preference sequence marked on the ballot paper. If on retabulation of the results of the ballot there is still no candidate with an overall majority of votes then the candidate with the lowest tally of votes in this round of counting is excluded from the count and any allocated ballot papers are once again redistributed and recounted in the same way, according to the voters' expressed preferential sequence marked on their ballot paper. This process of re-distribution of ballots allocated to excluded candidates continues until a candidate has obtained an overall majority of votes (50% or more) in the final round of counting.
Candidate has been 'excluded' from the count can not receive any votes in a further redistribution and any votes to be re-distributed are distributed according to the next available preference allocated to an continuing candidate.
IRV with batch exclusion describes a two-round method of IRV where if no candidate receives a majority of the first round choices, all candidates but the top two are eliminated and all ballots are counted for whichever of the two runoff candidates is ranked highest on that ballot.
Examples
Example I
Imagine an election in which there are three candidates: Andrew, Brian and Catherine. There are 100 voters and they vote as follows (for clarity, third preferences are omitted):
| # | '39 voters' | | '12 voters' | '7 voters' | | '42 voters' |
|---|
| '1st' | Andrew | | Brian | Brian | | Catherine |
| '2nd' | Brian | | Andrew | Catherine | | Brian |
First, the first choices are counted, and the tallies stand at:
★ Andrew: 39
★ Brian: 19
★ Catherine: 42
No candidate has an overall majority of votes (which in this case would be 51), so Brian, who has the fewest votes, is excluded from the count. Brian's votes are then transferred to one of the two remaining candidates. To do this the ballot papers of the 19 Brian supporters are examined to see which candidates voters have given as their second choices. Each Brian supporter then has his or her vote redistributed according to their nominated subsequent preference instead. So 12 votes are now counted for Andrew and 7 for Catherine. The tallies then become:
★ Andrew: 51
★ Catherine: 49
Andrew now has an overall majority so is declared the winner.
Example II
Imagine another election in which there are four candidates: Andrea, Brad, Carter and Delilah. There are 120 voters and they vote as follows (fourth choices are omitted):
| # | '44 voters' | | '3 voters' | | '16 voters' | '10 voters' | | '47 voters' |
|---|
| '1st' | Andrea | | Brad | | Carter | Carter | | Delilah |
| '2nd' | Brad | | Carter | | Brad | Delilah | | Carter |
| '3rd' | Carter | | Andrea | | Andrea | Brad | | Brad |
The count would proceed as follows:
| Andrea | Brad | Carter | Delilah |
|---|
| Round 1 | 44 | 3 | 26 | 47 |
|---|
| Round 2 | 44 | 3 → '0' | 26 → '29' | 47 |
|---|
| Round 3 | 44 → '63' | | 29 → '0' | 47 → '57' |
|---|
★ 'Round 1:' First choices are tallied and no candidate has a majority (in this election an overall majority would be 61).
★ 'Round 2:' Brad has fewest votes so is excluded. His supporters all give Carter as their second choice. So his votes all count for Carter. However there is still no candidate with a majority.
★ 'Round 3:' Carter is now excluded and so his votes must be counted for their next choices. Because only Andrea and Delilah remain in the contest, Carter's votes will be divided between them according to which one is ranked next on each ballot. At this stage in the count Carter is regarded as having 29 votes. These 29 votes include 3 originally counted for Brad. His votes therefore come from three groups of ballot papers. The choices expressed on these ballot papers are:
| # | '3 voters' | '16 voters' | '10 voters' |
|---|
| '1st' | Brad | Carter | Carter |
| '2nd' | Carter | Brad | Delilah |
| '3rd' | Andrea | Andrea | Brad |
:On the basis of these ballot papers Carter's 29 votes are now counted for the two remaining candidates as follows: 19 to Andrea and 10 to Delilah. Note that the 16 ballot papers in the middle column list Brad as the second choice. However because Brad has already been eliminated these votes instead count for the next 'live' preference , which is Andrea.
★ 'Winner:' Once Carter's votes have been counted for next choices, Andrea has a majority of votes and so is declared the winner.
Handling ties
Exact ties can happen in any election; although the odds remain very low when many votes are cast, the multiple rounds of counting used in IRV create more opportunities for a tie than there are in some other voting systems. If there is a tie for last place in the elimination process, various rules can be used to break it:
#One candidate, from among those tied, is eliminated at random (e.g. by a coin toss).
#In Australia the candidate, from among those tied, with the fewest votes in the previous round is eliminated. If there is still a tie those counting votes then look back to the next most recent round and then, if necessary, to further progressively earlier rounds until one candidate can be eliminated.
#In Irish presidential elections the candidate, from among those tied, with fewest first choices is eliminated. Failing this those counting look ''forwards'', first to find the tied candidate with fewest votes in the second round and then, if necessary, to the third, fourth and subsequent rounds.
#In some private elections the method is to 'conditionally eliminate' candidates from the tie and recount to see if either (or any) can survive. Usually the full set will become eliminated in any order. However this option is not allowed in a political election because it would allow some voters to have two simultaneous votes.
In practice, before any of these methods are used, the first step is to see if a tie has any chance of actually affecting the result. If the total of all the combined votes of any grouping of the candidates with the fewest votes is fewer than the votes cast for the next weakest candidate, then all those bottom tier candidates can be eliminated simultaneously.
Ballot paper
As seen above, voters in an IRV election rank candidates on a
preferential ballot. IRV systems in use in different countries vary both as to ballot design and as to whether or not voters are obliged to provide a full list of preferences. In elections such as those for the
President of Ireland and the
New South Wales Legislative Assembly, voters are permitted to rank as many or as few candidates as they wish. This is known in Australia as 'optional preferential voting'.
Under optional preferential voting some voters may rank only the candidates of a single party, or of their most preferred parties. A minority of voters, especially if they do not fully understand the system, may '
bullet vote', expressing only a first choice. Allowing voters to rank only as many candidates as they wish grants them greater freedom but can also lead to some voters ranking so few candidates that their vote eventually becomes 'exhausted'–that is, at a certain point during the count it can no longer be counted for a continuing candidate and therefore loses an opportunity to influence the result.
To prevent exhausted ballots, some IRV systems require or request that voters give a complete ordering of all of the candidates in an election - if a voter does not rank all candidates her ballot may be considered
spoilt or an informal ballot. In Australia this variant is known as 'full preferential voting', and is used in elections for the federal
House of Representatives. However, when there is a large set of candidates this requirement may prove burdensome and can lead to "
donkey voting" in which, where a voter has no strong opinions about his or her lower preferences, the voter simply chooses them at random. Partly to overcome these problems, in elections to the Australian House of Representatives many parties distribute 'how-to-vote' cards (right), recommending how to allocate preferences on the ballot paper.
The common way to list candidates on a ballot paper is alphabetically or by random lot, a process whereby the order of the candidates published on the ballot paper is determined by lottery. In some cases candidates may also be grouped by
party.
Any fixed ordering of candidates on the ballot paper will give some candidates an unfair advantage, because voters, consciously or otherwise, are influenced in their ordering of candidates by the order on the ballot paper. The random ordering of candidates is intended to overcome this. The most effective form is
Robson Rotation, a system where the order of candidates on the paper is randomly changed for each print run of the same election's ballot papers. This means that any one ballot paper is almost certainly different from the next.
History and current use
Main articles: History and use of instant-runoff voting
Instant runoff voting was invented around 1870 by American
architect William Robert Ware. He evidently based IRV on the single-winner outcome of the Single Transferable Vote, originally developed by
Carl Andrae and
Thomas Hare. The first known use of IRV in a governmental election was in
1893 in an election for the
colonial government of
Queensland, in Australia. The system used for this election was a special form known as the
contingent vote. IRV in its true form was first used in
1908 in a State election in
Western Australia.
Today IRV is used in Australia for elections to the Federal House of Representatives, and for the
lower houses of all States and Territories except
Tasmania and the
Australian Capital Territory, which use STV. It is also used for the
Legislative Council of Tasmania. In the
Pacific, IRV is used for the
Fijian House of Representatives, and
Papua New Guinea has adopted it for its parliamentary elections. IRV is also used to elect the
President of Ireland and for
municipal elections in various places in Australia, the United States, and
New Zealand.
United States
★ Minneapolis, MN
[2] in November 2006 passed instant runoff voting with 65%. Implementation is scheduled for the 2009 municipal elections.
★ North Carolina adopted instant runoff voting for certain judicial vacancies and will encourage municipal pilot programs starting in 2007. The city of Cary
[3] will use IRV for mayor and city council elections
[4] in October 2007, and the city of Hendersonville will use IRV for city council elections in November 2007.
★ Pierce County, WA passed instant runoff voting in November 2006
[5] for implementation for most of its county offices in 2008.
★ Takoma Park, MD adopted instant runoff voting for city council and mayoral elections in 2006 after an 84% win in a 2005 advisory ballot measure. It held its first IRV election to fill a city council vacancy in January 2007.
[6]
★ Oakland, CA voters
passed a measure by 69% to 31% in November 2006 to adopt IRV for its city offices.
★ Burlington, VT held its first mayoral election using IRV in 2006 after voters approved it in 2005.
★ San Francisco has used instant runoff voting annually to elect its Board of Supervisors and major citywide offices since 2004.
★ Ferndale, MI passed instant runoff voting with 68% in 2004 pending necessary implementation.
★ Berkeley, CA passed instant runoff voting with 72% in 2004 pending necessary implementation.
★ Cambridge, MA has used the
single transferable vote with
Droop quota method of proportional voting, which is synonymous with IRV in the case of electing a single official, for more than 60 years.
[7].
★ Dozens of American colleges and universities
[8] use IRV, including as of November 2006 more than half of the 30 universities rated most highly by ''U. S. News and World Report''.
Application in absentee voting
Instant runoff voting and variations have been hailed as a solution to the logistical problems of overseas voting in states with runoff provisions. In the event of a runoff, election administrators would have to print new ballots, mail them to far-flung places, and receive them again. In the short window between the first election and the runoff, there often is not enough time. With a ranked instant runoff ballot, the votes of overseas citizens can count even if their first choice does not make the runoff, all on a single ballot. Arkansas, Louisiana and South Carolina all use this form of instant runoff voting on ballots for military and overseas voters.
Similar systems
Runoff-voting
The term ''instant runoff voting'' is derived from the name of a simpler class of voting systems called
runoff voting. In runoff voting voters do not rank candidates in order of preference on a single ballot. Instead a similar effect is achieved by using multiple rounds of voting, often held on different days. The simplest form of runoff voting is the two round system. Under the two round system voters vote for only one candidate but, if no candidate receives an overall majority of votes, another round of voting is held from which all but the two candidates with most votes are excluded.
Runoff voting differs from IRV in a number of ways. The two round system can produce different results due to the fact that it uses a different rule for eliminations, excluding all but two candidates after just one round, rather than gradually eliminating candidates over a series of rounds. However all forms of runoff voting differ from IRV in that voters can change their preferences as they go along, using the results of each round to influence their decision. This is not possible in IRV, as participants vote only once, and this prohibits certain forms of
tactical voting which can be prevalent in 'standard' runoff voting.
A closer system to IRV is the
exhaustive ballot. In this system only one candidate is eliminated after each round, and many rounds of voting are used, rather than just two. Because holding many rounds of voting on separate days is generally expensive, the exhaustive ballot is not used for large scale, public elections. Instant-runoff voting is so named because it achieves a similar effect to runoff voting but it is necessary for voters to vote only once. The result can be found 'instantly' rather than after several separate votes.
Contingent vote
Top-two IRV
The
contingent vote, also known as 'Top-two IRV', or ''batch-style'', is the same as IRV except that all but the two candidates with most votes are eliminated after the first round; the count therefore only ever has two rounds. This differs from the 'two round' runoff voting system described above in that only one ballot is conducted. The two rounds therefore both take place ''after'' voting has finished. Two particular variants of the contingent vote differ from IRV in a further way. Under the forms of the contingent vote used in
Sri Lanka, and the elections for
London Mayor in the
United Kingdom, voters are not permitted to rank all of the candidates, but only a certain maximum number. Under the variant used in
London, called the
supplementary vote, voters are only permitted to express a first and a second preference. Under the
Sri Lankan form of the contingent vote voters are only permitted to rank three candidates. The supplementary vote is used for mayoral elections while the Sri Lankan contingent vote is used to elect the
President of Sri Lanka.
While superficially similar to IRV these systems can produce different results. If, as occurs under all forms of the contingent vote, more than one candidate is excluded after the first count, a candidate might be eliminated who would have gone on to win the election under IRV. If voters are restricted to a maximum number of preferences then it is easier for their vote to become exhausted. This encourages voters to vote
tactically, by giving at least one of their limited preferences to a candidate who is likely to win.
Conversely, a practical benefit of the 'contingent vote' counting process is expediency and confidence in the result with only two rounds. Most apparent in smaller elections, like with under 100 ballots among a dozen choices, confidence can be lost in a bottom-up elimination due to cumbersome ties on the bottom (or near ties affected by counting errors). Frequent and even multiple use of tie-breaking rules in one election will leave uncomfortable doubts over whether the winner might have changed if a recount was performed.
Practical implications
Instant runoff voting is more complex, both in terms of casting votes and counting them, than simpler systems such as 'first-past-the-post' plurality. Voters have the power to rank candidates in order of choice rather than merely write an 'x' beside a single candidate. Changing from plurality to IRV may therefore require the replacement of
voting machinery, although several nations count ballot by hand.
IRV has been implemented in cities using optical scan machines, as in San Francisco (CA) and Burlington (VT). A hand count also is possible under IRV and is the method used in most non-American jurisdictions; however it is usually more time-consuming than a quick plurality count, and may need to occur over a number of rounds. It is nonetheless simpler than the count under some other preferential voting systems like the
single transferable vote. IRV is typically less expensive than runoff voting because it is only necessary for voters to go to the polls once. For this reason it may also be less likely to induce
voter fatigue.
Under IRV, unlike some other preferential systems, the record of votes cast in a particular area cannot be conveniently summarized for transfer to a central location in which they can be counted. If areas were to report the number of votes cast for each possible order of candidates, as in the examples above, the permutations can be very large as the number of possible orders is equal to the factorial of the number of candidates. Three candidates would produce only six combinations but five candidates would produce 120 and ten candidates 3.6 million. This unwieldiness could prolong the counting procedure, provide more opportunities for undetected
tampering than in more easily summable methods, and make recounts more costly. What happens in practice in Australia is a simplified count is sent through to the central location on the night with the actual ballot papers transported securely to the central location for the final count. In Ireland's presidential race, there are several dozen counting centers around the nation. Each center reports its totals for each candidate and receives instructions from the central office about which candidate or candidates to eliminate in the next round of counting.
Tactical voting and strategic nomination
Main articles: Tactical manipulation of instant-runoff voting
Instant runoff voting reduces the potential for
tactical voting by eliminating 'wasted' votes. Under the '
First Past the Post' (plurality) system voters are encouraged to vote tactically by voting only for one of the two leading candidates, because a vote for any other candidate is unlikely to affect the result. Under IRV this tactic, known as 'compromising', is typically unnecessary because, even if a voter's first choice is unlikely to be elected, his or her vote has the opportunity of being counted for second or subsequent choices, who may be more successful. However the tactic of compromising can still be used in IRV elections, as can another tactic called 'push over'. IRV is immune to 'burying' which is possible under some other preferential systems.
IRV election can under unusual circumstances be influenced by
strategic nomination; this is where candidates and political factions attempt to influence the result of an election by either nominating extra candidates or withdrawing a candidate who would otherwise have stood. Although hard to anticipate, IRV is vulnerable to strategic nomination for the same reasons that it is open to the voting tactic of 'compromising'. This is because a candidate who knows they are unlikely to win might be able to bring about the election of a more desirable compromise candidate by withdrawing from the race, or by never standing in the first place. By withdrawing candidates a political faction can avoid the '
spoiler effect', whereby a new candidate 'splits the vote' of its supporters. However, the spoiler effect is less of a problem in IRV than under the plurality system because there are opportunities for 'split votes' to be concentrated on one of the candidates as the rounds progress, whereas under the plurality system votes cast for a losing candidate are simply lost.
Effect on parties and candidates
Like other preferential voting systems, IRV encourages candidates to appeal to a broad cross section of voters in order to garner lower preferences that may be necessary for earning majority support. However, unlike some other preferential voting systems, IRV puts particular value on a voter's first choice; a candidate with weak first choice support is unlikely to win even if ranked relatively well on many voters' ballots.
IRV is an election method designed for single seat elections. Therefore, like other single seat methods, if used to elect a
council or
legislature it will not produce
proportional representation (PR). This means that it is likely to lead to the representation of a small number of larger parties in an assembly, rather than a proliferation of small parties. Under a
parliamentary system it is more likely to produce single party governments than are PR systems, which tend to produce
coalition governments. While IRV is designed to ensure that each individual candidate elected is supported by a majority of those in his or her constituency, if used to elect an assembly it does not ensure this result on a
national level. As in other non-PR systems the party or coalition that wins a majority of seats will often not have the support of an overall majority of voters across the nation. In Australia, the only nation with a long record of using IRV for the election of legislative bodies, IRV produces representation very similar to those produced by the plurality system, with a two party system in parliament similar to those found in many countries that use plurality. If the first preferences of Australian voters were counted on a First Past the Post basis, their elections would produce the same victors about 94% of the time.
[2]
Where preferential voting is used for the election of an assembly or council, parties and candidates often advise their supporters on how to use their lower preferences. As noted above, in Australia parties even issue 'how-to-vote' cards to the electorate before polling day, and Australia's requirement that voters must rank all candidates contributes to some voters using them. These kinds of recommendations can increase the influence of party leaderships and lead to a form of pre-election bargaining, in which smaller parties bid to have key planks of their platforms included in those of the major parties by means of 'preference deals'.
Majoritarianism and consensus
The intention of IRV is that the winning candidate will have the support of an
overall majority of voters. It is often intended as an improvement on the '
First Past the Post' (plurality) voting system. Under 'First Past the Post' the candidate with most votes (a plurality) wins, even if they do not have an overall majority (more than half) of votes. IRV addresses this problem by eliminating candidates one at a time, until one has an overall majority.
However, some critics argue that the majority obtained by the winner of an IRV election is not always a genuine majority, and that it is more accurate to say that IRV will elect the majority choice among the top two frontrunners. This is because there may be a candidate who is preferred by most voters to the winner of an IRV election, but whose lack of core first choice support led to elimination early in the IRV count. Advocates of this view argue that a candidate can only claim to have majority support if they are the 'Condorcet winner'—that is, the candidate voters prefer to every other candidate when compared to them one at a time. In fact, when IRV elects a candidate other than the Condorcet winner it will always be that the majority of voters prefer the Condorcet winner to the IRV winner. Defenders argue that first and other higher preferences are more important than lower preferences, and point out that the Condorcet winner may be a candidate with 0% of first choices who voters would only accept as a compromise candidate.
Because of the value it puts in first choice support, IRV may be less likely to elect
centrist candidates than some other preferential systems, such as Condorcet's method and the
Borda count (as long as voters list sincere choices, rather than strategizing). For this reason it can be considered a less consensual system than these alternatives. Some IRV supporters consider this a strength, because an off-center candidate, with the enthusiastic support of many voters, may be preferable to a 'mediocre' compromise candidate, while still being acceptable to a majority of voters.
IRV at times produces different results to a Condorcet count because it does not consider the lower choices of all voters, only of those whose higher choices have been eliminated, and because of its system of sequential exclusions.
Example
Consider again the choices of the voters in the election in Example I above. This time the third choices of the voters are important and so have been included:
| # | '39 voters' | | '12 voters' | '7 voters' | | '42 voters' |
|---|
| '1st' | Andrew | | 'Brian' | 'Brian' | | ''Catherine'' |
| '2nd' | 'Brian' | | Andrew | ''Catherine'' | | 'Brian' |
| '3rd' | ''Catherine'' | | ''Catherine'' | Andrew | | Andrew |
In an IRV election Andrew will be elected, whereas under Condorcet's method or the Borda count (with sincere voters) Brian would win. Favoring Brian is the fact that a majority of voters prefer him to Andrew. This can be seen by the fact that 61 voters have given him a higher ranking than his opponent. Furthermore Andrew is ranked last by 49 voters which seems to indicate that he is strongly disliked by almost one half of the electorate. Brian is either the first or second choice of every voter, which suggests that he is a broadly acceptable compromise candidate. On the other hand Andrew is the first choice of a large number of voters while Brian is the first choice of few. This might suggest that Andrew has the enthusiastic support of a large plurality of the electorate, while Brian is a compromise.
Evaluation by criteria
Scholars of electoral systems often compare them using mathematically-defined
voting system criteria. IRV passes the
majority criterion, the
later-no-harm criterion, the
mutual majority criterion, the
Condorcet loser criterion and, if the right tie-breaker method is used, the
independence of clones criterion. IRV fails the
monotonicity criterion, the
consistency criterion, the
Condorcet criterion, the
participation criterion,
reversal symmetry and the
independence of irrelevant alternatives criterion.
Sample procedure with complexities
This procedure allows for elections in which a single category of office may contain multiple seats, differing levels of majority are needed to win, and “none of the above” is allowed as an option. ''A suggested procedure for recording the results appears in italics.''
'Definitions'
All seats for each category of office shall be filled by a single “balloting”. Each balloting shall consist of one or more “elections”, each of which shall determine the winner for a single seat for that category of office. Each election shall consist of one or more “rounds”, each of which shall determine either a winner of the election or the lowest vote receiver for that round, who shall be eliminated from further contention in the current election. A ballot is “exhausted” when all the candidates listed on it have been either elected or eliminated.
'Voting procedure'
For each category of office, the voters shall complete a ballot listing any or all candidates in contention for that office, in descending order of preference. At the end of the list, the voter may also specify “NOTA” (“none of the above”) if he prefers a vacancy to any of the other nominees.
'Balloting tabulation procedure'
An election shall be performed for each seat of the current category of office. The winner of each election shall be noted, and the ballots shall be re-combined and another election performed until either all seats have been filled or all ballots have been exhausted. If all ballots are exhausted before all seats for the current category of office have been filled, then another balloting may be held to fill the remaining seats.
'Election tabulation procedure'
The ballots shall be separated into piles according to the first eligible candidate on the ballot who has not been elected in a previous election of this balloting. There shall also be a pile for exhausted ballots that specify “NOTA” and another pile for exhausted ballots that do not specify “NOTA”. ''On the first election for each balloting, construct a grid with a row for each candidate, another row entitled “NOTA”, another row entitled “exhausted”, another row entitled “ballots cast”, and another row entitled “needed to win”. On the first round of each election, label the next column “X.1”, indicating that this is round 1 of election X, and record the number of ballots in each pile in the cell of the corresponding row.'' Rounds shall be performed until either a winner is determined or all ballots have been exhausted.
'Round tabulation procedure'
The number of “ballots cast” shall be determined by summing the number of ballots in all piles other than the pile of exhausted ballots that do not specify “NOTA”. ''Record this number in the “ballots cast” cell.''
If the number of ballots in the pile of exhausted ballots that specify “NOTA” is a majority of the ballots cast, then the current election does not produce a winner, the balloting is over, and another balloting may be held to fill the remaining positions, in which all candidates who had not yet been eliminated in the current election shall be ineligible. ''Circle the “NOTA” cell.''
Otherwise, the number of “ballots needed to win” shall be determined by applying the level of majority needed to win to the number of ballots cast. ''Record this number in the “needed to win” cell.'' If the unexhausted pile that contains the most ballots contains at least the number of ballots needed to win, then the candidate represented by that pile is the winner of the current election. ''Circle that candidate’s cell.''
Otherwise, the candidate represented by the unexhausted pile that contains the least number of ballots is eliminated, the ballots in that pile shall be distributed to the other piles according to the next eligible candidate on the ballot who has not been eliminated in the current election or elected in a previous election of the current balloting, and the round tabulation procedure shall be repeated. ''Cross out the eliminated candidate’s cell, label the next column “X.Y”, indicating that this is round Y of election X, and record the number of ballots in each pile in the cell of the corresponding row.'' In case of a tie for the least number of ballots, the “tie breaking procedure” shall be employed to determine which candidate shall be eliminated.
'Tie breaking procedure'
Each pile shall be separated into sub-piles according to which of the tied candidates appears highest on each ballot (excluding the name of a tied candidate in his own pile). ''Label the next column “X.Y.1”, indicating that this is the first tie breaking iteration of round Y of election X.''
For each of the remaining originally tied candidates, the total number of ballots in all of that candidate’s sub-piles shall be determined. ''Record this number in each candidate’s cell. Do not record the number of ballots that do not correspond to any of the remaining originally tied candidates.'' The remaining originally tied candidate with the least number of ballots shall be the one eliminated. In case of a tie for the least number of ballots, the sub-piles of the candidate with the greatest number of ballots shall be distributed to the other sub-piles according to which of the remaining originally tied candidates appears highest on each ballot and this paragraph shall be repeated. ''Do not circle or cross out the greatest vote receiver’s cell. Label the next column “X.Y.Z”, indicating that this is tie breaking iteration Z of round Y of election X.'' A tie for the greatest number of ballots shall be resolved by the toss of a coin or coins.
Once the candidate to be excluded has been determined, the sub-piles shall be recombined into their original piles, the excluded candidate’s ballots shall be distributed to the other piles per the final paragraph of the round tabulation procedure, and the round tabulation procedure shall be repeated. ''Cross out the eliminated candidate’s cell, label the next column “X.Y”, indicating that this is round Y of election X, and record the number of ballots in each pile in the cell of the corresponding row.''
Economics
The use of IRV can significantly reduce the cost of conducting a public election whilst essentially producing the same outcome.
The adoption of a IRV or preferential ballot system provides economic benefits both directly and indirectly over the two round run-off voting system, potentially saving hundreds of millions of dollars in direct and indirect cost associated with the staging of two-round runoff ballot.
Additional saving are also achieved by minimizing the uncertainly of outcome that arises when a second round ballot is required. For example the costs involved in the holding of the 2007 French presidential election could have been halved and the results known soon after the first and only round of voting. The cost of holding a multiple round ballot in developing countries is prohibitive.
See also
★
List of democracy and elections-related topics
★
Table of voting systems by nation
★
Australian electoral system
★
Electoral systems of the Australian states and territories
★
Ballot Access News for occasional related news in the United States
★
Arrow's Impossibility Theorem
References
1. Australian Electoral Commission [1]
2. Australian Politics webpage on the effects of Preferential Voting [9]
External links
;Advocacy organisations
★
Instant Runoff Voting at
FairVote
★
★
History of IRV
★
[10] at
New America Foundation
★
Better Ballot Campaign IRV for Minneapolis (Hosted by
FairVote Minnesota)
★
instantrunoff.com, by the Midwest Democracy Center
[11]
★
FIRV (
Ferndale, Michigan for Instant Runoff Voting)
★
Californians for Electoral Reform
★
California IRV Coalition
★
Coalition for Instant Runoff Voting in 'Florida'
★
Green Party (United States)
★
History of Use in Ann Arbor
;Opposition positions
★
"The Problem with Instant Runoff Voting"
★
IRV page at the
Center for Range Voting
★
Flaws in IRV compared to ranked pairs
★
Ka-Ping Yee's Voting Simulation Visualizations
;Analysis
★
Nonmonotonicity in AV Article by Eivind Stensholt.
★
Comparison with
Condorcet Voting by Blake Cretney
★
Voting methods: tutorial and essays by James Green-Armytage (for IRV, see e.g.
1 2 3 4 5)
★
A Handbook of Electoral System Design from
International IDEA
★
Electoral Design Reference Materials from the
ACE Project
★
ACE Electoral Knowledge Network Expert site providing encyclopedia on Electoral Systems and Management, country by country data, a library of electoral materials, latest election news, the opportunity to submit questions to a network of electoral experts, and a forum to discuss all of the above
★
Simulation Of Various Voting Models for Close Elections Article by Brian Olson.
★
Preferential voting in Australia
;IRV in practice
★
[12] San Francisco Department of Elections on its IRV elections
★
[13] City of Burlington, Vermont on its IRV elections
★
[14] Blog focused on implementation of IRV in Pierce County, Washington
★
[15] City of Takoma Park, Maryland on its IRV elections
★
[16] City of Cary, NC
;Examples
★
IRV Poll For 2008 U.S. Democratic Party Nominee at ChoiceRanker.com (formerly Indaba.org)
★
IRV Poll For 2008 U.S. Democratic Party Nominee at demochoice.org
★
IRV poll for U.S. President, 2004 by the
Independence Party of Minnesota
★
OpenSTV -- Open source software for computing IRV and STV
★
''Favourite Futurama Character Poll''
★
[17]in Guatemala
;Legislation
★
Presidential Elections Act, 1993 - Republic of Ireland
★
Commonwealth Electoral Act - Australia
★ U.S.
House Resolution 2690 - "Voter Choice Act of 2005"
★ U.S.
[18] - Examples of U.S. IRV laws
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