Voting system change boosts Labor and Greens in Brisbane City


I posted back in March about the Queensland government’s proposed reforms to local government in that state. The reforms include a bunch of other changes to electoral finance and council procedures, but I focused on two proposed changes: introducing compulsory preferential voting for single-member elections, as well as introducing proportional representation with compulsory preferences for multi-member elections.

It appears that the latter point is not included in the legislation which was introduced earlier this year and was the subject of a parliamentary inquiry, with it being treated as “the subject of further consultation”. This solves the problem of voters being required to number an absurd number of boxes, but it means we’re stuck without any proportional representation in Queensland council elections for now.

The government is proceeding with the other key piece, which would switch from optional preferential voting (OPV) to compulsory preferential voting (CPV) for elections of mayors and for single-member wards (the map of which councils would be covered by this change is included in this post). This echoes the change made to the state electoral system prior to the 2017 state election.

This system change will most likely have the biggest impact in the City of Brisbane, Australia’s biggest and most important local council, where optional preferential voting has seen a lot of Labor and Greens votes exhaust rather than helping the other party, and where the LNP’s large council majority could be under threat.

By my estimate, I think a switch from OPV to CPV would flip three marginal LNP wards to Labor, while bringing about 2.3% closer to control of the council.

To calculate the change in preferences, I looked at how preferences flowed in the nine Brisbane-area electorates at the 2019 federal election. The AEC publishes preference flow data split up based on the voter’s first preference, whereas state election results do not separate preferences by first preference. About 83% of Greens preferences flowed to Labor ahead of the LNP in these seats.

Most preferences flowing in Brisbane City in 2016 were from the Greens. Only four candidates outside of Labor, LNP or the Greens ran for a council seat in Brisbane in 2016 (in four different wards). The redistribution spread those voters’ votes over nine out of 26 wards, but in most wards preferences would just flow from the Greens.

I assumed a preference flow of 80% to Labor for Greens voters, and 50% to Labor for the small number of independent or other minor party voters. There were four wards where the Greens outpolled Labor, and in these wards I assumed an equivalent preference flow of 80% from Labor to the Greens.

After applying these preference flows, this is how the margins for each ward changed:

WardPartyOPV old boundariesOPV new boundariesCPV new boundaries
Bracken RidgeLNP60.6%59.6%57.4%
Forest LakeALP55.3%55.4%57.3%
Holland ParkLNP54.8%54.0%52.0%
PaddingtonLNP vs GRN55.8%55.6%53.3%
PullenvaleLNP vs GRN68.1%68.0%64.0%
TennysonIND vs ALP76.3%73.3%73.1%
The GabbaGRN vs LNP55.0%56.8%58.2%
The GapLNP55.7%54.5%52.6%
Walter TaylorLNP vs GRN66.5%65.7%63.1%

The voting system change has a much bigger impact than the redistribution. Three wards flip to Labor: Coorparoo, Doboy and Northgate. Coorparoo comes out with a 2PP of 50.02% for Labor.

Labor also gets closer to winning a majority overall, or at least depriving the LNP of a majority. There are currently two members of the crossbench, and the Greens are close enough in Paddington to factor that into swing estimates. The following table shows the swings needed to achieve changes in who holds the majority on council.

ScenarioOPV old boundariesOPV new boundariesCPV new boundaries
LNP lose majority5.7%5.6%3.3%
ALP + GRN gain majority8.0%7.5%5.2%
ALP gain majority8.3%8.9%6.5%
Lord mayoralty flip9.5%9.5%7.7%

The uniform swing required for the LNP to lose their majority, for Labor and the Greens to win a majority between them, or for Labor to win a majority in their own right, all reduce by 2.3-2.4% with a change to the voting system. The swing needed for Labor to win the lord mayoralty drops by 1.8%.

All of a sudden the swing needed for the LNP to lose complete control looks quite achievable, at 3.3%. This would require to lose six wards. Three of these are wards where Labor would likely be leading under CPV without any additional swing, plus Holland Park, the Gap and Paddington (where the Greens are the main challenger). Even a 5.2% swing to give Labor and the Greens a combined majority doesn’t seem out of the question.

We don’t have any polling for the Brisbane City race, so we can’t assess whether such a swing is possible. Labor will have been out of power in City Hall for sixteen years by the time of the election next March, so I could imagine a change in the voting system being the impetus for a more serious threat to LNP control, and potentially a change in Brisbane.

Finally, this map shows the wards of Brisbane, coloured according to who would win under CPV, with the wards flipping to Labor marked in pink.

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  1. Are Greens/ALP voters more likely to already give preferences. If so, would that also make them less likely to vote informally first time after the change?

  2. @Jonathan D
    Yes, to the first bit. The LNP actively run a campaign against preferencing (often with black and white signs that have tiny authorisations), and Labor and the Greens do the opposite.

    For the 2nd bit I’d expect so but to a limited extent since the LNP will change their material and LNP voters are more likely to follow that generally speaking.

  3. Looking at this mornings Courier Mail State Poll they had better start training their voters because every vote will count.
    Jackie Trad is dragging down ALP State Government and no one knows who Lord Mayoral Candidate is or will be?
    Is Greens Councillor Sri going to run for Lord Mayor or is the risk of losing his sinecure just too great?

  4. I imagine the Greens strategy for Council will be fairly similar to last time – fly the flag in every ward, go hard in the several they could win, run a noisy big-target Mayoral campaign to push the agenda forward.

    Sri is recontesting the Gabba, and their Paddington award candidate was announced this week. I don’t know of any others yet.

  5. Sunday Mail this morning has announced that ALP have dumped Lord Mayoral Candidate and replaced him with a TV personality. I despair that direct election of Lord Mayors results in the selection of Major Party candidates with very limited experience of local government. My previous comment about Sri high lites the problem. All of the ALP Councillors/ Aldermen have more experience than new Lord Mayoral Candidate. Ben’s response to my comment Sri would be mad to contest Lord Mayoralty shows that direct elections lead to the promotion of style over experience. It would be far better to have Councillors/ Aldermen elect the Mayor. The potential to have a Lord Mayor who does not have the confidence of majority of Councillors is a threat not worth risking.

  6. I actually don’t think it’s right to have the Mayor also be a Councillor when there are single member wards. There’s both a small conflict of interest, and a huge conflict of time. Especially somewhere like BCC with over 600,000 voters and 26 wards; SEQ metro councillors work full-time for a reason.

    For councils elected proportionally at large (and with more councillors per voter), absolutely the Mayor can just be selected by the council chamber (ticket leaders = Mayoral candidates essentially).

    The reforms proposed for rural Qld have the Mayor also being able to run for Councillor and the introduction of STV for Councillor elections. This will likely have the same end result of Mayoral candidates leading tickets.

  7. Caboolture Times this week reveals details of review into Moreton Bay Regional Council . Review has been released because Mayor not prepared to trust Councillors with not leaking content. Sutherland does not reveal which MBRC Councillors in his opinion can not be trusted.

  8. Alexi’s comments about the potential conflict of interest of a Mayor also representing a ward has some validity.
    However this is nothing to the potential conflict of interest of a Councillor having interests in land development or real estate. No Councillor should be able to own land other than their home and business
    .A person who owns land in Councilarea other than home or business should be able to run for council. Once a person has nominated for council Local Authority should never be able to Re one any land in which the candidate has an interest.
    We have no choice but to break the actual conflict of interest between local government and land development real estate industries.
    We also have to grasp the thorny issue of Councillor’s spouses. I favour placing the same obligation on all family members who have lived under same roof as Councillor in las ten years as is placed on Councillor. No one has suggested that Jackie Trad’s husband buying a house adjoining river crossing was NOT a conflict of interest but Ms Trad MAY not have known and perceivable may not have been compromised. Only solution is to place the obligation on the equivalent of Jackie Trad’s husband to list the asset.
    Local Government in Queensland needs a massive clean up and this can only occur if Local Government becomes more clearly political. Currently the political element of Local Government outside of Brisbane is clouded behind a multitude of independent candidates endorsed by local political party branch’s without the oversight of Political Party governance. Red HTV = party A, Blue HTV = Party B, etc etc. I have no delusions that my Mayor is Liberal and that my previous Councillor was ALP. However at elections this affiliation was opaque and possibly in other cases covert. Political affiliation needs to be declared and parted need to either endorse or stay out of Local Government altogether. I favour political party involvement. I will probably face a field of half a dozen independents most of whom will have no policy other than anti corruption and communication. Most will never have read the Council Budget Papers and will be a mix of ego centric peacocks, protesting half wits or real estate agents. Formal Political Party endorsement would clean up a lot of these making the choice for electors clearer.

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