There are different voting systems for each house of Parliament in Western Australia.
Voting system for the Legislative Assembly
Candidates are elected to the Legislative Assembly through full preferential voting. This is a system whereby a candidate must poll an absolute majority of the total formal votes (in excess of 50% in order to be elected.)
This system is characterised by the elector numbering all squares on the ballot paper in order of preference. The ballot paper markings should clearly reflect the elector’s intention.
If, after all first preference votes have been counted, no candidate has obtained an absolute majority of all formal votes, then the candidate with the fewest number of first preference votes is excluded from the count. The excluded candidate’s second preference votes are then distributed to the remaining candidates at this stage.
If, after that exclusion, no candidate has obtained an absolute majority of formal votes, the next remaining candidate with the fewest votes is excluded and all of his or her votes (second preferences and those received from the previously excluded candidate) are distributed to the remaining candidates.
The process is continued until one candidate is elected by obtaining an absolute majority of formal votes. The absolute majority is calculated excluding informal and exhausted votes.
Voting system for the Legislative Council
Proportional representation is the voting system used in multi-member electorates such as the Western Australian Legislative Council.
To be successful, a candidate is required to receive enough votes to reach a quota (not an absolute majority) which is based on the number of formal votes and number of candidates to be elected.
Electors mark their ballot, allocating preferences to their preferred ranking for all candidates. A successful candidate must achieve a quota, calculated using the following formula:
Subsequently, if the quota is not reached the candidate with the least number of votes is excluded and their votes redistributed according to the second preference shown. This process continues until a candidate reaches a quota.
Candidates, who receive a number of votes equal to or greater than the quota are elected immediately. Any votes of these elected candidates, which are surplus to the quota, are transferred to the remaining candidates at a reduced value known as a transfer value.
Local government elections
Local government and other elections use the ‘first-past-the-post’ system. This means that electors indicate their preferred candidate(s), and the candidate with the most votes is elected. Where there are multiple vacancies, the candidate with the most votes is elected first, and the candidate with the second highest number of votes is elected second, and the process continues until all vacancies are filled.