Under Hare-Clark, a party’s total vote is not the only thing that matters for how many seats you win. In a close race, the relative distribution of votes between your candidates can make a difference.
A party with more than one quota can sometimes be in a position to win an extra seat if their vote is spread relatively evenly amongst their viable candidates, rather than concentrated between leading figures. This means that each candidate can stay in the race long enough to gain other preferences and eventually win with less than a quota.
Kevin Bonham coined the term “Ginninderra effect” to refer to what happened in the electorate of Ginninderra in 2012, where Labor polled 2.39 quotas compared to 0.61 quotas for then-Greens leader Meredith Hunter, but won three seats. A slightly less dramatic but similar result took place in 2016, with Labor polling 2.48 quotas and the Greens polling 0.58, but Labor winning three seats.
One of the ways that you can ensure an even distribution is by splitting up an electorate into different geographic areas, and having candidates who perform better in each one. This can either be a natural result of candidates coming from a particular area, or a deliberate strategy by a party to ask their candidates to campaign in one area, or to hand out different material in different areas. I’ve previously analysed this pattern in Tasmania for the 2021 and 2024 elections and for the 2016 ACT election. It seems like these patterns are more natural for Tasmania, but in the case of the ACT it does look like there are some deliberate strategies pursued, although it’s very hard to confirm.
For this post I’m going to pick some of the electorates and look at maps showing which of the candidates within each of the major party groups polled highest in each booth.
I’m also going to look at the curious case of the Greens in Kurrajong, who won a second seat in 2020 without seeming to pursue these strategies, and aren’t doing so this year.
This table shows what proportion of the party’s vote went to each candidate in 2020. You can see that in Kurrajong, Labor’s vote was extremely strongly concentrated behind Andrew Barr. Shane Rattenbury also dominated the Greens vote in Kurrajong, and Liberals Jeremy Hanson and Alistair Coe also did very well in Murrumbidgee and Yerrabi respectively.
Labor’s vote was split almost evenly between their first two in Brindabella, with their third not far behind. Ginninderra’s Labor vote was also very concentrated before their first three candidates, and Yerrabi is also very even. The Liberal Brindabella vote was also very evenly split.
Brindabella
Three Labor candidates won booths in Brindabella in 2020. Joy Burch tended to win booths in the north of the electorate, while Mick Gentleman dominated the south. Taimus Werner-Gibbings also managed to win three small booths.
The Liberal pattern is not as clear, although there was also a very close tie between the top two, and a third polling over 20% of the party’s vote.
Nicole Lawder topped the vote in five booths in a cluster in the north of Tuggeranong, while Parton won a bunch wrapping around that area. Andrew Wall won two booths in the south while Jane Hiatt won one booth.
Ginninderra
Yvette Berry did notably better than her Labor colleagues in Ginninderra, but not overwhelmingly so, and Tara Cheyne also won a smattering of booths in the centre of the electorate.
I won’t bother to post the Liberal map as almost every booth was won by Elizabeth Kikkert – three other Liberals each won a single booth. It’s not a good position for the Liberals, considering Kikkert’s late departure from the Liberal ticket and her candidacy for Family First.
Kurrajong
Andrew Barr is very dominant in the Labor vote here, so I’ve posted a map showing the top-polling Labor candidates after excluding Barr.
Maddy Northam and Rachel Stephen-Smith have a very clear geographic divide, with Stephen-Smith dominating the south and Northam the north. But Barr’s surplus was about as big as Stephen-Smith’s primary vote, so that played a big role in deciding the second Labor seat.
Elizabeth Lee was a clear leader for the Kurrajong Liberals, but not that far ahead of Candice Burch, the second-placed Liberal who didn’t end up getting elected.
Lee dominated the north side of Kurrajong, but Burch won three of four booths on the south side. The south has been playing a smaller role in Kurrajong over successive redistributions, but Lee is clearly favoured in the north.
The case of the Greens in Kurrajong is a fascinating example of a party that seems to not be making any progress towards splitting the vote.
In most cases for the Greens, they are only trying to win one seat so there is no point spreading out their vote – far better to concentrate the vote behind one person.
But the Greens have now won two seats in the central electorate twice: first in the seven-member Molonglo district in 2008, and again in the new five-member Kurrajong district in 2020. In 2008, there was no effort to identify a second candidate – their successful second candidate Caroline Le Couteur barely polled any more than the third candidate – but in 2020 Rebecca Vassarotti was clearly identified as a second lead candidate.
Unsurprisingly, Shane Rattenbury absolutely dominated the Greens vote in 2020 despite Vassarotti’s being positioned as the second Greens candidate. Rattenbury won the Greens vote in every booth in Kurrajong. Indeed the Greens preference order played out very clearly with Vassarotti coming second in every booth and third-placed Adriana Boisen coming third in all but three small booths.
But it is more surprising that they don’t appear to be making much of an effort to spread out their vote between Rattenbury and Vassarotti in 2024, even though that could be crucial to Vassarotti’s success in a close race. The Greens how-to-vote card clearly has Rattenbury as the #1 candidate. This seems like a mistake.
Murrumbidgee
The Labor and Liberal vote in Murrumbidgee was concentrated behind a leading candidate who got around 40% of the party’s total vote, while the next two candidates for each party were relatively evenly placed. So I excluded Chris Steel (Labor) and Jeremy Hanson (Liberal) from these maps, but when I did so, there wasn’t much pattern as to where the remaining candidates’ primary votes came from in their race for the second seat for each party.
Yerrabi
Then-Liberal leader Alistair Coe played a dominant role in the Liberal vote in Yerrabi, but the Labor vote is a bit more interesting, with three candidates polling between 20% and 28% of the total Labor vote.
Michael Pettersson and Suzanne Orr were both elected, but with Deepak-Raj Gupta and Georgia Phillips not that far behind. All four won at least one booth, with Pettersson dominating in central Gungahlin and Orr dominating in the south, including the small parts of Belconnen in the electorate.