Hare-Clark is Tasmania's proportional representation system using the single-transferable vote. It was developed by Englishman Thomas Hare and modified by Andrew Inglis Clark, Tasmanian Attorney-General. It was used in the Hobart and Launceston multi-member electorates between 1896 and 1902, and statewide since 1909. From 1909 to 1956 there were five six-member seats, and in an attempt to avoid 'hung' or balanced parliaments, five seven-member seats – an uneven number – between 1959 and 1998. Now, following a reduction in the total of MPs, five five-member electorates exist.
The minimum vote required for election is known as the Droop quota. It is calculated by dividing the total valid vote plus one, by the number of seats plus one. Ignoring extended fractions, the 35-member quota was 12.5 percent, the current 25-member quota 16.7 percent. Not all elected candidates achieve a quota, because votes of excluded candidates are 'lost', and ballots may become 'exhausted' if electors vote for only five candidates, rather than more or all candidates in order of preference.
To cast a valid vote, voters must record at least five preferences numbering from 1 to 5. Should a candidate gain sufficient first preferences to reach a quota, he/she is declared elected, and all preferences are distributed. If a candidate has a surplus (above the quota), these votes are transferred as a fraction to the next in line.
This fraction or reduced value uses the Gregory method (named after mathematician JB Gregory), although any small 'remainder' is lost. If another candidate is elected, his/her surplus is distributed to continuing candidates at a further reduced value (surplus divided by votes in last parcel of votes received). After all surpluses are dealt with, if candidates still have insufficient votes, those with the fewest votes are excluded and their votes are transferred. This is done at full value if votes were gained as No 1's, or at the reduced value at which they were received. After literally several hundred counts, sometimes the last person elected is simply the remaining candidate after others with lower votes are excluded.
Ballot papers listed all candidates alphabetically until 1941, when separate columns for political parties and other groupings began. Lots are drawn to determine columns across the ballot and positions down the columns. Since 1979, the Robson Rotation (named after Neil Robson MHA) requires the rotation of candidates' names within columns. This supposedly evens out indiscriminate 'donkey' or up- or down-the-ticket voting, and generates batches of different ballot papers in each electorate. These are distributed at random, an ultra-fair process which makes it hard for party machines to organise 'tickets'. This feature is said to favour independents over party machines, because safe seats cannot be determined and/or allocated using registered party lists, since 'No. 1' votes and other preferences remain the prerogative of individual voters.
Since 1922, by-elections for vacant seats have been determined by recounts of originally contesting candidates, using ballot papers from the previous election. The only exception was a polling-booth by-election for all seats in Denison in 1980, following a Supreme Court challenge because a candidate exceeded the electoral spending limits. Despite some criticism for complexity, Hare-Clark also has worldwide repute for fairness, although 'hung' Parliaments or closely balanced election outcomes can occur.
Further reading: T Newman, Hare-Clark in Tasmania, Hobart, 1992; N Robson, Everybody counts, Hobart, 2003; www.electoral.tas.gov.au.