Hare-Clark electoral system

ACT Legislative Assembly elections use the Hare-Clark electoral system to elect members to parliament.

The Hare-Clark system is a kind of proportional representation known as a ‘single transferable vote’ system.

This means electors - people casting a vote - number their preferences for individual candidates by writing '1, 2, 3, 4, 5' and so on against the names of candidates on the ballot paper.

Read about ballot papers.

Each elector has a single vote, but that vote can be transferred from candidate to candidate according to the order the elector writes on their ballot paper.

To be certain of election, a candidate needs a quota of votes. The quota for each of the ACT’s 5-member electorates is about 16.67% of all votes cast.

The quota is calculated by:

• dividing the number of formal votes by one more than there are vacancies in the election
• then adding one (1) to the result.

For an ACT’s electorate with five vacancies this means:

• dividing the number of formal votes by 5 plus one more (5 + 1) which is a total of 6
• then adding one (1) to the result.

Read about electorate boundaries.

Counting the votes

After the polls close, every number one (1) vote is counted. The quota is calculated after all the valid first (1) preference votes have been counted.

In this first count, if a candidate gets enough number one votes to reach the quota they are elected.

Additional votes above the quota are called a 'surplus'. Surplus votes are transferred to candidates who are still in the count, according to the numbers electors have written on their ballot papers.

Surplus votes are not always worth a full vote. They are often transferred to other candidates at a reduced value. This value is determined by dividing the number of surplus votes by the total number of ballot papers with further preferences shown on the ballot papers.

If there are still candidates to elect, and no other surplus to transfer, the candidate with the fewest votes is 'excluded' from the count. Their votes are re-allocated to other candidates according to voter’s preferences.

This process of excluding unsuccessful candidates and transferring elected candidate's surplus votes continues until the required number of candidates have been elected.

Read the Hare-Clark factsheet.

Filling casual vacancies

When an elected member of the Assembly resigns, retires or dies, they leave a 'casual vacancy'.

The vacancy is filled by recounting only the ballot papers that contributed to the election of that member.

Only unsuccessful candidates who contested the original election and who choose to contest the casual vacancy can be elected in a 'casual vacancy countback'.

If it is not possible to fill a casual vacancy using this method, the Legislative Assembly will choose a person to fill the vacancy. This has never happened under the Hare-Clark electoral system in the ACT.

Read the Casual vacancies factsheet.