How a Hare-Clark Count Works

10am today is the close-off time for receipt of Tasmanian election postal votes. After these votes have been added to the count, the Tasmanian Electoral Commission will begin an amalgamation count, where ballot papers by candidate by polling place are amalgamated into bundles of ballot papers by candidate by electorate.

Once amalgamation is complete, the Electoral Commission will begin distributing preferences. Over the next few days I will have a dedicated post for each division where I will summarise the progress of the 2024 count.

To visualise how the distribution of preferences takes place, this post summarises the 2021 count progress for Bass. It explains why vote for parties is much more important under Hare-Clark than it is at Senate elections, where above-the-line party votes control the count. Both Senate and Hare-Clark counts are conducted as contests between candidates, but with Hare-Clark the split of party votes between candidates is much more than at Senate elections.

The chart below shows the party totals at Count 1, the final tally of first preference votes.

If this were a Senate contest, you would say three Liberal and one Labor members will be elected from filled quotas. The final seat would be a race between the surplus quotas for each party. The Liberal Party has an initial party surplus of 0.60 quotas, Labor 0.56, and the Green total is 0.55 quotas.

But this is a Hare-Clark count, not a Senate count. In a senate race more than 95% of votes would be with the lead candidate in each party group making the first four seats clear. In Hare-Clark, the votes are more evenly distributed between candidates, though the Liberal ticket in Bass at the 2021 election looked more like a Senate tally with 80% of the Liberal votes cast for one candidate, Premier Peter Gutwein.

In general there are four types of preferences in quota-preferential counting systems such as the Senate and Hare-Clark.

  • Trickle down – preferences from over quota candidates overwhelmingly flow to other candidates in the group.
  • Fold-up – preferences from excluded lower polling candidates in a group generally flow up to higher polling candidates in the same group.
  • Between party leakage – both trickle down and fold-up preferences can produce leakage out of a group due to voters who do not number preferences for all candidates in a group before numbering preferences in a different group.
  • Between party last candidate flows – when the last candidate in a group is excluded, any ballot paper with further preferences for a candidate remaining in the count flows on to other groups.
  • Some points to make on the above classification are –

    • At Senate elections, rates of trickle down and fold-up preferences are close to 100% because almost all votes are with the lead candidate. Votes completed using a party’s above-the-line voting square cannot leak out of the party ticket.
    • At Hare-Clark elections, there is generally a 5-10% leakage out of a ticket when a candidate is elected or excluded and preferences distributed. This figure tends to be higher when the last candidate is excluded because of accumulated preferences from already excluded candidates.
    • In Hare-Clark, parties adopt tactics to try and minimise leakage. With the Greens generally competing to win a single seat, the party defines its candidates as either lead or support in an attempt to concentrate support with one candidate and minimise leakage. The Labor and Liberal parties like to spread their vote more evenly between higher polling candidates, though the high profile of party leaders often works against evening out the vote.
    • Between party last candidate preferences will be more important in 2024 because of the increase in the number of groups with fewer than seven candidate, especially with 14 single candidate Independent groups.
    • Because Labor, Liberal and Greens groups stand full lists of seven candidates, equal to the minimum seven preferences for a formal vote, the majority of preferences exhaust when the final candidate of a group is excluded. The rate of preferencing beyond the ticket tends to be higher for Labor and the Greens to the advantage of both parties over the Liberals.

    So let me graph the Count 1 total of primary votes by candidate for a different picture of the count.

    2.89 of the Liberal Party’s 3.60 quotas had a first preference for Premier Peter Gutwein. 1.89 of his 2.89 quotas will be distributed as preferences. Something called a Transfer Value is calculated and then applied to all ballot papers held by Gutwein. The Transfer value here is (Surplus Votes) divided by (Votes Held). This is done using vote totals, but for simplicity here I will express it as 1.89/2.89 = 0.65. So if 100 of Gutwein’s ballot paper have next preferences for Candidate A, then 100 ballot papers will flow at vote value (100 * 0.65) equals 65 votes. A complex explanation but I’m always being asked how it is done.

    The transfer value formula gets more complex when a a candidate reaches a quota on preferences. Of Gutein’s surplus, 9,294 votes (and by votes I mean ballot papers times transfer value) had next preference for Sarah Courtney putting her 295 votes over quota. The transfer value formula here is (Surplus Votes) divided by (last votes received) which is 295/9294. All of the ballot papers transferred from Gutwein to Courtney are examined and transferred at a new transfer value to the next available preference. Note that under Hare-Clark, Courtney’s first preferences were not examined as part of the surplus. In the Senate system, all votes held by a candidate are examined for distribution, not just the last received.

    But away from formulas and back to what happened in the count. Count 2 distributed Gutwein’s surplus. 43.7% of preferences flowing to Sarah Courtney putting her just over quota, and 33.9% to Michael Ferguson leaving him just short of a quota. 9.1% of Gutwein’s preferences leak to other tickets, lowering the total Liberal vote to 3.42 quotas against Labor 1.68 quotas and the Greens 0.57 quotas. This loss of preferences from the Gutwein surplus greatly diminishes the Liberal Party’s chances of winning a fourth seat.

    Count 3 distributes Sarah Courtney’s small surplus leaving the votes by candidate as shown below.

    After Count 3, The Labor Party total is 1.6793 quotas to the Greens 0.5682. More importantly, the two lead Labor candidates are Michelle O’Byrne on 0.7480 and Janie Findlay on 0.5640. As the bottom three Labor candidates are excluded, the vote for both candidates will increase which means Labor will have two candidates with more votes than the Greens ticket in total. And leakage of fold-up preferences from Greens ticket means not all Green votes will reach the lead Greens candidate Jack Davenport.

    Counts 4-22 proceeded to exclude one ungrouped, one Labor and three Greens candidates before finally excluding a Liberal candidate. This final exclusion put Michael Ferguson over quota and distributed his small surplus at Count 22 leaving the totals as below.

    After Count 22 the three exclusion have reduced the Greens total to 0.5481 across two candidates, in total short of Labor’s Michelle O’Byrne on 0.7686 and Janie Findlay on 0.5848.

    Counts 22-34 excluded the Animal Justice Party candidate plus a Labor and then the fifth placed Liberal candidate Lara Alexander.

    The Greens total across two candidates is now 0.5955 quotas, still short of second placed Labor candidate Janie Findlay. The Greens position worsens with Counts 31-34 excluding the second placed Greens candidate Anne Layton-Bennett. Only 83% of preferences flow to lead Greens candidate Jack Davenport leaving him now well short of the two leading Labor candidates.

    Counts 39-42 exclude the third remaining Labor candidate Adrian Hinds. There is a 14% leakage of preferences but Michelle O’Byrne still reaches 0.98 quotas and Janie Finlay 0.76, both well ahead of Jack Davenport on 0.58 quotas. The totals after Count 42 were –

    Count 43 distributed all full value ballot papers for Andrew Harvey (SFF) which generally flowed to Labor and Liberal candidates and put Labor’s Michelle O’Byrne over quota. Counts 44-46 distributed a smaller number of reduced transfer value ballot papers and Count 47 distributed Michelle O’Byrne’s small surplus leaving the totals as shown below.

    The final exclusion at counts 48-52 was the distribution of preferences for the fourth placed Liberal candidate Simon Wood. Of his preferences, 50.1% exhausted, 37.5% flowed to Labor’s Janie Findlay leaving her just short of a quota on 0.9962, rounded to 1.00 in the chart below. Only 12.4% flowed to the Greens’ Jack Davenport leaving him on 0.68 quotas.

    With no more candidates to exclude, Findlay was declared elected with just under a quota. 0.32 quotas of votes exhausted during the count.

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