2025-2028 2PP Aggregate Methods Page

Because I have way too many things to do right now I decided in my usual fashion to do one more that isn't any of them!  Introducing my 2025-2028 federal 2PP polling aggregate, which at this very early stage sits at 56.3 to Labor, with an overall pattern of basically no 2PP movement since it had enough data to wake up on 29 June.  The above is a 7-day smoothed aggregate though it has been as high as 57.2 on individual daily readings, and as low (a 0.8 point outlier lasting one day only!) as 55.5.  By the end of the term who knows if 2PP will even still exist the way the Australian right are going after this year's drubbing, but for the meantime, here we are.  Differences will be detected with aggregates that use pollster-released 2PPs (these tend to have Labor losing support more quickly) and also my estimate is currently running about a point below Bludger Track but with a similarly flat trajectory.  

The aim of the aggregate is to present a frequently updated figure for what the current polls should be taken as saying collectively about the state of the two-party preferred contest.  This is never a prediction or a statement that the polls are right, it is just putting a number on where they're at. 

This aggregate works quite differently from previous aggregates that had a simple 5-3-2-1 week of release formula, and does so mainly because of the increasing frequency of polls with long in field periods or late releases.  The mathematics are kept simple enough that I should be able to understand if something is going wrong (edit: indeed I fixed one glitch overnight after two August polls were found to have been entered as July; it made very little difference), but are no longer readily hand calculable to make my treatment of data less chunky and arbitrary.  The working of this year's aggregate is below:

* Activity: The aggregate is active when there are at least three different polls by two different pollsters with an age weighting (see below) exceeding 0.5.  At other times it freezes at its current value then numbers are interpolated once it re-activates.  

* Last election aggregate: The poll is based on my last-election 2PP estimates based off primary votes released by pollsters, using the formulae in this post (unless we get better data on Bradfield).  2PP figures released by pollsters themselves do not affect the aggregate.  In the 2022-5 term there was vast speculation about preference flows to the Coalition being stronger than in 2022, but this amounted in the end to virtually nothing, the latest crushing victory for last-election preferences over other approaches (though admittedly the latter had come around to the idea preferences wouldn't shift by the end).  

* Update frequency: The aggregate in theory updates daily, but it often doesn't change if no new polls have been released for a while. I will only usually check or log values in real time when a new poll comes out or when the aggregate changes (there is no longer a weekly reset, but some of the daily resets change the numbers for a few days while polls are fresh).

* Age weighting: A poll is added from the day of its release.  It is given a weighted data age related score which is based on a 2:1 weighting of the youngest and oldest days in field (these will be estimated if not known).  Outside of campaign periods this is set at a maximum weighting of 5 for a poll where the weighted age score is 7 days or less, and thereafter decays at the rate of x0.618 per week (spot the golden ratio!) calculated daily.  Polls discovered long after release will probably not be back-included. 

* Anti-swamping: Only the two heaviest age weighted polls by any pollster are included at any one time and the rest are dropped.  If a specific poll is swamping the sample by releasing weekly it will be downweighted.  The most recent polls by pollsters that release irregularly are not dropped from the sample (unlike my old aggregate) but will soon be downweighted by data age to the point of having virtually no influence.  

* Accuracy weighting: A poll is weighted by an accuracy statistic calculated from its table rankings in all included elections from the 2022 federal election onwards.  This will be updated after fresh elections that are included, however an election must be polled by at least four different pollsters to affect the rankings.  This works on a scale where a poll that consistently comes last is weighted at 0.50, a poll that is consistently midfield is weighted at 1.00 and a poll that consistently tops the table is weighted at 1.50.  (As I start this aggregate Newspoll has the highest weighting at 1.35 followed by Redbridge at 1.11).  A new pollster gets a weighting of 0.8 and a pollster that has less than five elections is capped at 1.1 for one election, 1.2 for two (etc).  Party/lobby group commissioned polls are excluded, as are polls I consider to be junk polls and polls banned for ludicrous incompetence.  There is no sample size weighting except that any poll with a sample below 900 is downweighted by 50%.  

* House effects: Polls may be assigned house effects based on their average difference from the aggregate during the term, or based on the average of the last six differences in the case of a strong appearance of a temporary divergence.  This will only be done where the divergence is at least half a point.  

* Inclusion: Polls must include at minimum primary votes for both majors and the Greens.  Polls that do not also include a One Nation breakout are downweighted by 50%, and are also taken out behind the shed and flogged.  Polls included at present are: Newspoll, YouGov, Redbridge, Resolve, Roy Morgan, DemosAU, Essential, Freshwater, Spectre, Ipsos, though not all have yet released results in this term.  

* Automatic reset: The aggregate resets if there is a change in Prime Minister.

Other aggregates

Bludger Track - BT aggregates primary votes then determines a 2PP from them.  

Mark the Ballot -  based on pollster-released 2PPs.

Wikipedia - also based on pollster-released 2PPs

Updates

Substantial updates to methods will be logged here if there are any.

Poll Roundup: Liberal Crisis As Honeymoon 2.0 Rumbles On

 Cross-poll estimate 56.3 to Labor (+1.0 since election)

I'm some way off putting out a 2025-8 term polling aggregate, partly because I am hoping that when the dust settles from the Bradfield court challenge in coming months we might get revised 2PP flow figures for Bradfield to enable more exact 2025 election preference flow estimates.  And partly just for sheer lack of time.  But this week's federal polls have been notable and there are a number of themes I think are worth covering off on quickly to put what is going on in historic context.

Newspoll

This week's Newspoll came in at 58-42 to Labor off primaries of ALP 36 L-NP 27 Green 13 One Nation 10 others 14.  The Coalition primary is the worst in Newspoll history by two points.  The previous worst was two polls ago in July and it was then the worst in Newspoll history by two points.  The Coalition primary is now four points lower than it had been in any previous term.   

No Government has led 58-42 since Kevin Rudd's led 59-41 in October 2009, and the last Newspoll this lopsided was Julia Gillard's Labor trailing 42-58 shortly before Gillard was removed in June 2013.  No Government beyond its first term has ever led 58-42 in a released Newspoll 2PP.  I convert one poll in June 1987 as 58-42 to the Hawke Government, one in Sep 1994 as 57-43 to Keating and there was a published 57-43 to the Howard government in September 2001.  One of these was a rally round the flag for the government after the 9/11 terrorist attacks, and the other two were the opposition disasters that were the Joh for Canberra Coalition split and Alexander Downer.  

How Labor Won 94 Seats Off A Modest Primary Vote. It Mostly Wasn't Preferences

Example of a 2025 election whinge meme seen on social media

In the unhinging that has followed Labor's massive victory in the 2025 federal election, there has been a lot of scapegoating of preferential voting.  Some of this may be because the landslide seat result was unexpected.  In polls this mostly looked like a close election in terms of whether Labor could get a majority or not.  Many voices in the media made it worse by claiming Labor definitely or very probably would not get a majority, and continuing to claim it after the polls (such as they were) no longer supported that view.

Labor won 94/150 (62.67%) of seats with a primary vote of 34.56%.  Many people are saying this was caused by preferential voting.  In fact, it mostly wasn't.  This article explains how this 28.11% gap between Labor's seat share and their vote share was mostly caused by other factors.   I find it deeply unfortunate and concerning that many people are in response attacking our very fair voting system and supporting instead the pointless abomination that is first past the post without bothering to understand the arguments in favour of preferences and the extent to which the result was caused by other things.  If they really care about parties getting vote shares that match their seat shares, they should support multi-member electorates.  

Hare-Clark! Why Do We Have It? Are There Any Alternative Approaches?

It had to happen and was always going to happen sooner or later after the 2025 election; in fact I'm surprised it has taken so long.  The Tasmanian Chamber of Commerce and Industry, or at least its chief executive Michael Bailey, has seen fit to call for the abolition or modification of Tasmania's Hare-Clark system.  I could just as easily see fit to bluntly suggest that they stay in their own lane.  I wouldn't expect to be taken seriously if I declared myself an expert in business regulation so I'm not sure why they expect to be so on this subject.

In the article in question, which is paywalled, the call is made to either replace Hare-Clark with single-member preferential voting or to switch from five seats of seven to seven seats of five.  

7x5, a zombie bad electoral take

Seven seats of five is an old chestnut that was roundly disposed of during the process of restoring the House from 25 to 35 members.  As the concept of restoring the House to 35 seats gained traction in the 2021-4 term there was some support for doing it by going to seven five-member electorates instead of going back to five seven-member electorates.  There was at the time only one Independent elected as such in the parliament, so the main motivation was to make things hard for the Greens.  Anyone who is remotely familiar with that debate would be aware of the TEC's discussion paper that showed significant problems with the 7x5 model.  One thing wrong with it is that it would require Tasmania to uncouple from the federal electoral boundaries and have its own state electoral boundaries process at an expense estimated at $2.5 million plus $300,000 per election.  Being almost as large as the federal divisions and overlapping with them extensively the state boundaries would then cause a lot of voter enrolment confusion; the TEC also suggests it would be difficult to avoid severely splitting up communities of interest by drawing a line through Hobart City.  (This said, it would get rid of the across-river divide in Franklin for state but not federal purposes, and drawing the boundaries of Clark in a completely sensible manner is getting more tricky anyway; more on this down the track).