Single transferable vote
Simple To Vote, Ngawari noa iho poti
Simple To Vote, Ngawari noa iho poti

How a candidate is elected for more than one vacancy

If there is more than one vacancy and more candidates than vacancies, STV works like this:

Setting the quota

The quota needed to get elected in an election where there is more than one vacancy, is the number of votes being counted divided by one more than the number of vacancies. For example, for an election where there are three vacancies and 1,000 votes, the quota is 1,000 divided by 4 (3+1) = 250.

The quota is recalculated whenever votes can't be transferred (for example because the vote expresses only one preference and the voting has progressed to second preferences).

Deciding an outcome on the count of first preferences

In an election with 1,000 votes for three vacancies, if three candidates get 250 or more first preference votes, those three candidates will be elected. Votes will not need to be transferred to second and later preferences to decide the outcome because enough candidates have already reached the quota.

Deciding an outcome if none or insufficient candidates win on the count of first preferences

If say two candidates reach the quota in an election for three vacancies, it may be necessary to go only to second-preference candidates to decide the other successful candidate. This is done first by transferring any surplus votes for the two candidates who reached the quota, to the second preference candidates of the voters who voted for those two candidates. If as a result a third candidate reaches the quota the election is complete.

Alternatively, if there are no surpluses to transfer, the candidate with the lowest number of first preferences is excluded and votes for that candidate are transferred to the second preferences of voters who voted for that candidate. If as a result a third candidate reaches the quota that candidate is elected and the election is completed.

However, it is more likely that even after the transfer of surpluses of elected candidates or transfers to second preference candidates following the exclusion of a candidate, insufficient candidates have reached the quota. If this is the case, the next lowest-polling candidate is excluded and the second-preference votes for that candidate are transferred to the other candidates. But some of those second-preference votes may be for the candidate who was excluded first. In this case, these votes are further transferred to the third or subsequent preferences of those voters.

On the other hand, some of the second-preference votes may be for the candidates who have already reached the quota. In this case the keep values for the elected candidates are recalculated and further transfers are made to voters' third and subsequent preferences.

This continues until sufficient candidates reach the quota. The computer system used ensures that the order in which votes are counted does not affect the outcome.

Equal votes
If, on any count, two or more candidates have an equal number of votes and one of them has to be excluded, the electoral officer determines which candidate had the fewest votes the first time the candidates' totals were different and excludes the candidate with the lowest total votes.

Ties
If the candidates had an equal number of votes at all stages of the count, a random (or pseudo-random) process is used to choose which candidate is excluded.

 

Example one

Candidates A, B and C are elected. There is no need to include second preferences.

 

Example two

Candidates A, B and C are elected.

* Candidate may have received further transferred votes but surpluses above the quota would have been transferred on to other candidates

**Normally the surplus votes for candidate C would be further transferred but in this case remain with that candidate as the computer counting program terminates once the required number of candidates are elected. Official results of elections are required to show candidates in the order they are elected and so candidate A would be shown as elected first, then candidate B followed by candidate C.

 

Example three