The Single Transferable Vote (STV) electoral system will be used for the 2016 elections for mayor and councillors of Palmerston North. STV was used for the 2013 elections and 2015 by-elections. It replaces the First Past the Post electoral system which had been used previously.
Under STV, electors rank candidates according to preference, rather than by ticking names of the candidates they wish to vote for. Electors may rank as few or as many candidates as they wish, regardless of the number required to be elected.
How do you vote with STV?
In an STV election, you use numbers instead of the ticks you use in First Past the Post elections.
It is simple to vote. Instead of putting a tick beside the candidates you want to vote for, you rank them with numbers. In other words you put them in order of preference. You begin with '1', for the person you like best.
By giving the number 1 to a candidate, you are saying that the candidate is your number one choice. By ranking candidates in your preferred order - 1, 2, 3, 4 and so on - you are saying which other candidates you prefer if your top choice doesn't have enough support to get in, or does not need all the votes they got to be elected.
You can rank all the candidates on the voting document, or as few candidates as you wish.
How are candidates elected?
Candidates must reach a certain number of votes to get elected. This is called a quota and is based on the total number of votes cast and the number of people needed to be elected to fill all the vacant positions.
How are votes counted?
Within New Zealand STV, votes are counted using specially developed computer software after all votes have been received. The counting process begins by tallying all first preference votes.
If a candidate is elected, they keep only the proportion of the vote they need to reach the quota. The surplus part of each vote is transferred to the voters' second choice. The votes are then re-tallied and, if another candidate gets more votes than they need to be elected, again the surplus part of each vote for that candidate is transferred to the voters' third choice. This process is repeated until enough candidates are elected to fill the vacant positions.
The transfer of votes is done in order of voters' preferences. This means that surpluses are not 'wasted' but are available to help other candidates to get elected.
If a candidate does not have enough support to get elected, all votes for that candidate are also transferred to voters' next choices. This means if a voter's first choice candidate is not elected, their vote goes towards the next candidate they selected.
The system treats all candidates the same, by giving them a 'keep value'. This allows them to keep the portion of the vote they need to be elected but allows any extra or surplus votes to be distributed proportionately amongst the other candidates, according to voters' preferences.
For example, if the quota or number of votes required to gain election is 100, and a candidate receives 100 votes, they keep all of those votes, so they have a keep value of 1 (i.e.100%).
But if the candidate received 200 votes, they still only need the equivalent of 100 of those votes to be elected, and the surplus can be transferred to voters' second choices. The candidate's keep value would be 0.5 (i.e. 50%), because that person only needed to keep 50% of all the votes they received in order to be elected.
This means the lower the keep value, the more votes the candidate received. The most popular candidates will have the lowest keep value, because they received so many votes, they only needed to keep a small proportion to gain election.
For detailed information on STV, see the information on the Internal Affairs website. It includes examples of STV elections showing how candidates are elected where there is one vacancy, and how candidates are elected when there is more than one vacancy.