Now that we have the final voting figures for the City of Brisbane, it was possible to update the analysis of preference flows and the impact of optional preferential voting (OPV) that I published prior to the election.
Immediately after the election, it became clear that there had been an increase in the proportion of Greens preferences flowing to Labor and vice versa at the 2024 election, compared to the 2020 council election.
For this blog post I am comparing the 3CP figures in wards where the final three candidates were LNP, Greens and Labor (which was in 24 out of 26 wards in 2024) to the two-candidate-preferred figure to determine the preference flows.
This table compares preference flows from Greens to Labor and vice versa at the 2020 Queensland state election (using compulsory preferential voting) and at the 2020 and 2024 Brisbane City council elections (using optional preferential voting).
| Voter group | Prefs to ALP/GRN | Prefs to LNP | Exhausted |
| Greens prefs (CPV) | 80.1 | 19.9 | |
| Greens prefs (OPV 2020) | 47.0 | 10.1 | 42.9 |
| Greens prefs (OPV 2024) | 54.0 | 11.5 | 34.5 |
| Labor prefs (CPV) | 74.6 | 25.4 | |
| Labor prefs (OPV 2020) | 41.3 | 12.2 | 46.5 |
| Labor prefs (OPV 2024) | 45.7 | 16.2 | 38.1 |
The proportion of preferences exhausting dropped significantly in both directions. The proportion of the remaining preferences remained roughly the same, so the LNP did also gain preferences. But with most preferences flowing to Labor or Greens, a lower exhaustion rate helps both parties in contests against the LNP.
For this next chart, it just shows wards or state seats in the Brisbane area where Labor and the Greens made the top two, and it shows how preferences from the Greens on the 3CP split.
Since there are no exhausted preferences for federal elections, the Labor and LNP preference flows add up to 100% and thus they are all on a line of X = 1 – Y.
It’s very obvious here that the rate of preferences flowing in 2024 was higher than in the 2020 council election, with the exhaust rate dropping by about 10%. Thus the 2024 results were a bit closer to what you’d get under compulsory preferential voting.
As I did with the 2020 results, I have then estimated how different the margins would have looked under compulsory preferential voting.
For this analysis I’ve just looked at the 24 wards which ended up as a contest between the LNP and either Labor or Greens. It doesn’t cover Tennyson (won by an independent) or Moorooka (where Labor won and the Greens came second).
I think Labor would have won Northgate and Wynnum-Manly under CPV.
Interestingly I don’t think the Greens would have picked up any extra wards under CPV, but the margin in Central, Coorparoo, Walter Taylor and Enoggera would have been much closer, with the Greens at 49% or more in all four.
To be honest, I had expected the difference between OPV and CPV to be bigger, with such an even split in support between Labor and the Greens leading to a lot of exhaustion and thus the potential for more wards to produce a different outcome under CPV. The limited number of wards where the LNP would have lost under CPV partly reflects how few wards ended up being that close. The LNP only won with a margin of less than 51% in just one ward: Northgate.
But the first chart makes clear that the gap between OPV and CPV in 2020 is not as wide as the gap between CPV and the 2024 OPV results.
While there’s just two wards that would have flipped, if you look at the margins it’s not insignificant. CPV would have reduced the LNP’s margin for lord mayor from 6.4% to 4.3%. The LNP would need to lose five wards to no longer hold a council majority. Under the actual result, a uniform swing of 2.3% would have been needed for the LNP to lose five wards. Under CPV, that swing would have just needed to be 0.4%.
The choice of system does make a difference, with the party in the lead winning more often under optional preferential voting, while two trailing parties can exchange preferences more efficiently under compulsory preferential voting. But while some compare OPV to first-past-the-post, it’s not the same thing. Preferencing behaviour can change, and that can change the outcomes.
Thanks for that Ben. It most likely would still have been “close(r) but no cigar” for the Greens in a few more seats under CPV. It baffles me that Labor never changed the voting system for BCC – especially given they had announced that they would but for whatever reason they changed their mind. As your post shows, they’d have two more seats in Council today if they had (and possibly 1 last election as well – the Greens would also have won Paddington in 2020 as well, but I guess they’ve won it now in any case so (apart from it being a differnt candidate) in party terms the same outcome has now happened in any case.
But I’m wondering why you have Central listed as Labor vs LNP seat when the Greens outpolled Labot by about 18% on primary votes?
I expect under CPV the Greens may well still have fallen just short in Central too – probably also by less than 1%, as with 3 other seats you’ve listed as Greens vs LNP contests,=. I expect it would have been closer than Enoggera but maybe a bit further away than the WT and Coorparoo.
But in any case, Central was very much was a Greens vs LNP 2CP contest.
Thank Ben. Two points.
The % of exhausted votes in 2020 was, IMO, high. Nearly 1 in 2 people chose not to preference.
The % of exhausted votes in 2024 was, IMO, still significant. Nearly 1 in 3 people chose not to preference.
IMHO this still indicates to me that a significant % of the population deliberately chose where and when to preference as far as they wish to. In 2024 for one reason or another people chose to preference further than they did in 2020. To put it in the opposite terms if CPV was in place in either election a significant % of the population would be forced to preference beyond what they would voluntary chose to do – despite the imaginary need to prevent voters falling down the trap door and exhausting their ballot accidentally.
I think Central ward may have been included in the 2024 dataset by mistake, or maybe it was mislabeled. The Greens came second on the primary vote there, but the chart says it shows wards where the Greens came third.
Also, I suggest you look at postal vs in-person to check the exhaust rate of Labor and Greens votes. Anecdotally, I heard that ‘just vote 1’ was much more prominent in postal ballots, even for those voting 1 Labor or Greens. If there were more postals in 2020 during the onset of COVID (which is possible, but I haven’t checked the numbers), then that might go some way to explaining the change in exhaust rate. People voting in-person likely have a dozen campaign volunteers and signs from Labor and the Greens reminding them to number every box, while people filling out a postal ballot don’t.
But Neil, does it actually indicate that, or does it actually show that most voters are just lazy and don’t want to make any more effort that they’re required to?
Yes there was a bug in my results data where I’d transposed the Labor and Greens primary in Central and had the ALP listed as being in the 2CP. I’ve fixed it now. The numbers for Central were correct – 47% on OPV and 49% on CPV.
Wilson, I think the answer is that we don’t really know whether those voting just ‘1’ for either Greens or Labor did it on purpose or accidentally.
Some may do it as a deliberate ‘protest’ vote to signal that they don’t support the views of the other party, or perhaps they actually dislike the other party more than the opposing LNP.
I think the gap between OPV preference flows and CPV preference flows is partly explained by people not bothering or not understanding the system, or in some way being influenced by ‘just vote 1’ messaging that they shouldn’t, but would otherwise be happy to indicate preferences, and is also partly about people who understand the system and sincerely don’t want to indicate preferences.
It seems unknowable as to how much is in each group, and I suspect there are still plenty of the former exhausting their votes in BCC.
I find it fascinating that the ratio of preferences in OPV or CPV seems to remain fairly steady, it’s just the total volume of preferences declines. In the case of classic races, there’s no evidence that those who vote Greens then exhaust are more likely to favour Labor or LNP than those who don’t exhaust when CPV forces them to preference.
To me that leans me towards the lazy/unaware thesis rather than the principled objector thesis. Although again I’m sure both are true for some voters.
Of course this time the “Just vote 1” messaging came only from the LNP. I don’t suppose they really cared much whether their own voters obeyed it – their preferences were only distributed in one ward – but they were clearly hoping to influence Labor and Green voters by it, and they managed to save 2 wards. In the one ward where LNP prefs were distributed – Moorooka – they went 20.2% to Labor and 8.5% to Greens, with 71.3% exhausting. So now we know – 28.7% of LNP voters can actually think for themselves!
I thought about trying to extrapolate from the ALP vs GRN contest in South Brisbane in 2020 to Moorooka but I think there’s too much uncertainty there. Firstly, very different areas. Secondly, tiny sample size. But most importantly, LNP preferences are so much dependent on their HTV decisions.
While I’m sure the ‘just vote 1’ LNP campaign would’ve had some effect on their voters in Moorooka, I also think it reflects that many LNP voters genuinely wouldn’t have a Labor vs Greens preference and would be quite happy to have the option to opt out, just as the party does with its HTV decisions – I’ve never heard of a situation where the Libs or LNP has picked a side between Labor and Greens under OPV, whereas they always have to under CPV.
I sometimes liken it to forcing someone to choose one of two poisons. And then you say “or you could just not take either poison” – they’re going to choose the not-poison option!
@Andrew Bartlett The argument over whether Labor should or shouldn’t have changed the electoral system to benefit their own results is part of the reason why people become so cynical about politics. Historically every change to voting systems has been introduced by the ALP except for “contingent voting” (OPV) in 1892.
Every single instance of that has backfired – from the dismissal of the Legislative Council (Queensland’s Upper House) in 1922, the year after a referendum voted against doing exactly that; to the introduction of the Electoral Districts Act in 1949 to develop a zonal weighting system.
I don’t believe the ALP has a future in Brisbane City – mainly due to demographics it will end up as a Green vs LNP council. Their best chance is to run under the ALP banner in areas where they currently run strong “independent” campaigns – Ipswich, Logan and perhaps Moreton. Running endorsed candidates in regional areas such as Cairns, Townsville, Rockhampton and Gladstone is probably feasible but there are some fairly entrenched factional players in those areas who wouldn’t welcome head office wandering around.
When we’re talking about different voters’ attitudes to how they vote, let’s note that one kind of voter is described in highly pejorative terms of “lazy” or “unaware”, while the opposite kind of voter is described in the highly positive term of the “principled objector”.
This framing of one voter as stupid and another voter as smart will inevitably bias the discussion in one direction – the dumbing down of the preferential system to the lowest level to satisfy the fools as much as the forthrights.
Why don’t we simply recognise that most voters are fulfilling the task that is required of them at that time? (That requirement should be whatever the voting instructions are, but it naturally also includes whatever messages that the political volunteers and advertising express.)
More importantly, let’s focus on the democratic question that the election is trying to solve – [b]which candidate will be chosen?[/b]
If we harshly disparage these people who’ve publicly put their hand up for election as “poison”, then we’re only helping to increase people’s disengagement with politics, and by extension, with democracy. No two candidates are the same, and everyone who votes formally helps elect one of them, no matter whether we’re using OPV or CPV. The difference is that in OPV, all voters whose votes exhaust have no say in who that ultimate winner will be, while in CPV, everyone chooses the winner together.
[b] was of course an attempt to see if it would make that text bold [/b] – oh well, that didn’t work.
I am not saying that anything is poison. I’m using an analogy from the Liberal perspective. It’s pretty obvious that preferencing Labor or Greens is poisonous to the Liberals, and when they have a third option they choose it.
I don’t think people who vote 1 without genuinely lacking further preferences are stupid. We have quite a complicated system. But I am specifically talking about people who would be happy to give a clear preference between the others if the question was presented in that way. But it’s not, so they don’t. I think “unaware” is a reasonable description and is not pejorative. And yeah, some of them are lazy, not all of them.
“in OPV, all voters whose votes exhaust have no say in who that ultimate winner will be”
Of course they have a say. They’ve been offered a choice and they’ve opted out.
@ Peter
Some good points and I can only express my personal thinking and reasoning for supporting OPV. I fully accept that for some unquantifiable number of people, not fully preferencing is just doing the bear minimum as set out in legislation. Who knows whether they are dumb or smart, I could be dumb for all I know.
I naturally have to disagree with your last sentence, because by inference you are painting the OPV as somehow inferior to the CPV because they didn’t fully participate in the voting process, which is in essence doing what you started out rallying against – setting one group up against another. Personally I think there are a LOT of dumb voters out there who wouldn’t vote if given the chance or shouldn’t vote because of how they came to their position, but I would not go as far as to say we should have some test as to whether some people could vote or not. At some point we have to accept that we have compulsory voting; and these are all adults that for all intensive purposes have the capacity to make valid choices.
@Neil Flanagan The choice of whether or not to fully preference is still a choice, and a valid one at that. In my submission to JSCEM I argued in favour of electronic voting with a guided process to reduce informals. But I also argued that the deliberate casting of an informal vote was still a choice that must be preserved and any system that was devised must not remove the right NOT to cast a vote in any way the voter wished to.
@Comment “People voting in-person likely have a dozen campaign volunteers and signs from Labor and the Greens reminding them to number every box, while people filling out a postal ballot don’t.”
Also the LNP has a much better postal vote campaign than the ALP and spends more money on it. Postal votes aren’t really part of The Greens campaign mix. They don’t really do Declared Institutions either and their attendance at prepoll is a bit hit and miss.
By the way, there were some questions about the exhaustion rate for different vote categories. I’ve got a post scheduled for Monday about voting methods for BCC, but I did also calculate the exhaustion rate for each vote type.
It was 7.2% for Ordinary votes, and also 7.2% for postal votes. It was 7.6% for pre-poll votes, 9% for absent votes and 10.6% for other votes.
So doesn’t look like postal votes had a higher exhaust rate.
The only way to quell the “Just Vote 1” is to have the state Election and Council Election on the same day.
Congratulations, that is a truly terrible idea. Look at what happened with the state by-elections held on the same day.
First there By-Elections, having the state election would discourage it cause most of vote 1’s are from LNP votes and wouldn’t risk losing seat’s because of it. The downside is slower election results
Caleb, Ben is making the argument that voters have difficulty complying with 2 sets of instructions simultaneously. Many informal votes under full preferences for the state by elections were caused by voters defaulting to the ‘easier’ set of OPV rules, so by your logic it would actually make it worse with more people reverting to ‘just vote 1’ instead of switching to using more preferences.
Irrelevant question but if Australia elections were voluntary and was held on a weekday, would there be significantly lower turnout given:
– The high turnout (close to normal election levels) of By-Elections are due to it being hold on Saturday in addition to many (or even most) thinking it was compulsory.
– A better indicator is SSM Postal Survey as it has a lower turnout (79%) but even then Australians were used to voting
Marh, by-elections follow the same rule as standard ones and are compulsory too.