Possums Pollytics

Politics, elections and piffle plinking

Pollycide Part 3 – The Verification.

Posted by Possum Comitatus on July 20, 2007

Continuing on from Pollycide 1 where we used various weights derived from the quarterly Newspoll data to give us some experimental 2 party preferred results to show us the type of seats that would have likely changed hands in a July election, and following on from Pollycide 2 where we then used some linear programming to fit that seat pattern into the actual swings observed in the quarterly Newspoll – we now take it all back to basics, because sometimes the simple things in life are… well, simple and effective.

I noticed some dubious reaction to how these seat swings are possible (well, I noticed them once I managed to get past all the ALP supporters throwing confetti everywhere), so I thought we’d get back to the basics to show that I’m not making this up.

To do this, we’ll use the Newspoll quarterly data from March-June 2007, and compare that to the actual 2004 Election results to give us the TPP swings for each state. We can then compare these swings using the State Pendulums and we’ll get a basic, but realistic assessment of the seats that would have been likely to change hands were an election held in July.

To start off with, let’s take a squiz at the 2004 Election TPP results and the Q2 Newspoll data to find the state swings:

2004 Election





















2007Q2 Newspoll





















ALP Swing







Coalition Swing







That entry “ALP Swing” is the one you want to pay attention to here.

Now comparing these swings to these graphs we get the following numbers of seats changing hand for each state:

NSW: ALP gain of 17

Vic: ALP gain of 8

Qld: ALP gain of 14

SA: ALP gain of 5

WA: ALP gain of 2.

That’s a total gain of 46 seats.

However, lets look at Tassie and the NT where Solomon would fall with a 2.9% swing, Bass would fall with a 2.7% swing and Braddon would fall with a 1.2% swing.

With a national swing of 9.8% – it’s a safe bet that those three seats would all fall as well, giving us a total ALP gain of 49 seats.

The Pollycide 2 numbers and the seat list suggested 47 seats would have been lost in NSW, Vic, Qld, SA and WA. Remember, that seat list was derived from Pollycide 1, and adjusted to fit within the State based swings – although it was more luck than skill that the numbers matched up just about perfectly as it could have been 3 or 4 seats in either direction due to the nature of the maths and where I chose to draw the line in terms of leaving some unaccounted for swing in NSW.

So, from Pollycide Part 1 we can see the types of seats that would have been lost in a July election, from Pollycide Part 2 can see a good estimation of which seats and the margins involved were an election held in July, and with Pollycide 3 we have verified those numbers.

That’s the good news for the government. Yes, the GOOD news.

The bad news is that the above verification based on the state Newspoll swing estimations doesn’t account for the composition of marginal and safe seats. The ALP are only swinging 4.1% toward them in their safe seats, the marginals are swinging 9.3% toward the ALP and the safe government seats are swinging 14.6% toward the ALP for an overall national swing of 9.8%.

As there was residual swing left from the seat calculations in Pollycide 2 (which is where we tried to account for the marginal and safe seat movements), that means that the swings actually underestimate the actual seat numbers that would have been lost.

By how much? – up to 10-15 seats depending on where the residual swing fell.

So what we can feel fairly safe saying is that were an election held recently, according to 3 months worth of polling by Newspoll, the ALP would have gained 49 seats as a minimum, somewhere around 55-60 seats as a more likely possibility and a high of somewhere around 65.

That really is a Pollycide.

If you want to check out the details of any of the seats mentioned in the Pollycide series, Adam Carrs magnificent psephology site has a smorgasbord of info on all of them in his 2007 Federal Election Guide.

Small Update – I over counted NSW by 1 as a result of putting a seat in the wrong spot in my NSW swing graph.Its all fixed up now with NSW giving 17 seats rather than 18.

Thanks to the dozen or so people that pointed it out – nothing get’s past you folks.

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18 Responses to “Pollycide Part 3 – The Verification.”

  1. lurker said

    I have to admit I wasn’t convinced by part 1 because of the problems with the weighting – but these next 2 parts are more convincing. That’s if the Newspoll data are accurate when broken down into components. It would be nice to have more seat by seat polling to be sure.

    I still have trouble believing that 18 seats will fall to the ALP in NSW and 14 in Qld! I also think the ALP will only pick up 3 seats in SA. I can’t seem to find the info, but I think Boothby has been Liberal since time immemorial.

    Out of interest, how do the seats compare to before 1996 and 1983? I’m wondering if a lot of the swinging voters who used to vote for Hawke/Keating but deserted the ALP for Howard are now returing to the fold.

    Still if even half these seats fall to labor it will be a wipeout.

  2. Stig said

    OK, starting to get more plausible.

    I still reckon you need to verify where possible in some specific seats (Bennelong as suggested) in order to reality-check your conclusions. I’ve done some digging, but can’t find any other recent seat-specific polling info. Can anyone else help?

  3. lurker said

    This poll was done a while ago (in Jan) and sample size is a little on the low side but shows results for 3 marginals in Adelaide.


    Kingston poll 56-44 possum 59-41
    Wakefield poll 61-39 possum 59-41
    Hindmarsh poll 60-40 possum ?

    So possum’s numbers are plausible.

  4. Ken said

    I’ve looked at your analysis – it seems to make sense however I don’t actually believe that come election day the ALP will be that far ahead.
    What we’d all like to know is that if the TPP was 50 / 50 and all the other factors as mentioned were in the same proportion but paired back to reflect a tpp of 50/50 (swinging, safe, city, non-city, state) who would win and at what tpp would there be a hung parliament.

  5. Stunkrat said

    Sorry Ken, I have no interest in knowing any of that.

  6. Eric said

    I reckon it will even up a bit before the election. Is does appear, however, that the seats are getting closer together on the pendulum. Would you agree? Maybe voting prefs correlate less to geography than they used to.

  7. Stig said

    Ken – as mentioned in one of the earlier pollycide posts, the way the swing is on looks like a reverse of the 1998 result, where Beazley scored a majority of votes but minority of seats. This was because the swing he had was concentrated in ALP safe seats. This time the swing is in marginals and L/NP safe seats. That opens the possibility that a TPP of 49% or even less could be enough for the ALP to win.

  8. Stig said

    Thanks lurker for your poll numbers. I’m usually ignorant about what is published in the GG, so I missed these.

  9. Stig said

    I’ll add in the Morgan phone poll in mid-February on Bennelong – TPP ALP 55%, L/NP 45%. Still looking plausible…

  10. Possum Comitatus said

    Many thanks Lurker and Stig for the work.Much appreciated.

    I know it all does seem like a massive amount of seats – but I’m just going where the polling data takes me.

  11. nysa said

    So if Howard bails on the 26th (his birthday) does that throw all this good analysis out the window?

  12. lurker said

    No problems Possum. I recall a Galaxy poll in Bennelong a couple of months ago that was 52-48 to the ALP. Galaxy’s ALP vote seems to be slightly lower than Newspoll’s or Morgan’s so it’s within the ballpark of Possum’s 56-44 Newspoll analysis.

  13. carbonsink said

    In The Oz this morning:
    Young voters desert Howard

    THE Howard Government has suffered a dramatic slump in support among young Australians as secret Coalition research shows one in four voters aged 18-24 have swung to Labor since Kevin Rudd became Opposition Leader

  14. Stephen L said

    The real problem for the government is that while its supporters furiously deny the credibility of analysis like this the MPs are going to be scared. Every one of the MPs in those 49 seats, and probably a few beyond, is going to be calling for top-up funding.

    In an election where the Coalition will be outspent by the ALP across the board that means a serious financial problem in the marginals, even allowing for the ridiculous amounts of taxpayers’ dollars incumbent MPs now get to spend. Add in the ACTU campaign and the Libs are going to be drastically outspent in the marginals, unless the party admin stand up to the holders of seats on 5-12% margins, in which case they risk wiping the party out permanently.

  15. James said

    What is the ALP Victory index at?

  16. Possum Comitatus said

    Stephen L,

    That is an enormous problem for the Coalition.Managing the scarcity of the funding is seriously problematic for them, especially if what the quarterly Newspoll suggests is true – in that there are more safe seats in danger than marginals.If you were a Coalition strategist responsible for allocating campaign resources, where would you defend?

    The ALP Victory Index has flat lined at the level it was last shown at.I might repost an updated version at the end of August.This is a problem with most of the polling at the moment – there’s a hell of alot of commentary going on about a set of polls that arent actually doing anything. It’s just more of the same 55/45 ALP TPP with primaries stuck around 46-48/39-41.

    The real story there is the absence of movement.

  17. […] Pollycide Part 3 – The Verification. « Possums Pollytics […]

  18. Tanks To Information….

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