In a few idle moments, I’ve knocked together a linear regression model to fit the results of the 2008 election in the vague hope it might shed some insight on where Labor and Liberal over- and under-performed. I’ve limited this to metropolitan electorates, because the relationship between voting and the most potent explanatory variable income breaks down beyond the city limits. I’ve also excluded electorates where independents reached the final count in the preference distribution (i.e. Churchlands, Alfred Cove and Kwinana).
On my first run I simply looked at income, and two not unexpected factors stood out. Parties over-performed where they had a sitting member defending their seat, and Labor over-performed in the inner-city and Fremantle. So I added two extra variables to the model: the Greens primary vote, to serve as a proxy for inner city-ness, and another variable which assigned a value of -1 to seats with a Liberal incumbent, 1 to seats with a Labor incumbent, and 0 to seats which were vacant. From these variables, Labor’s two-party vote can be modelled as 0.681 -0.419a +0.781b +0.056c, where “a” is a measure of median family income, “b” is the Greens primary vote and “c” is the incumbency variable. This explains 86% of the variation in the two-party results.
The following table ranks seats according to how Labor performed relative to the expectation of the model, from highest to lowest. The columns show median family income from the 2011 census, actual Labor two-party preferred, Labor two-party preferred according to the model, and the candidate situation at this election. “Sophomore” refers to situations where a party has gone from not having a sitting member at the 2008 election to having one in 2013, hence excludes situations where the sitting member has changed as a result of by-elections. “Vacancy” refers to the opposite situation, meaning a retiring sitting member in four cases and a mid-term by-election loss in the fifth (Fremantle).
MFY 2PP MODEL DIFF 2013 CANDIDATE West Swan 1879 54.4% 47.7% 6.8% ALP sophomore Perth 2536 57.8% 51.7% 6.1% ALP incumbent Warnbro 2008 59.7% 53.8% 5.9% ALP incumbent Nollamara 1450 62.7% 57.4% 5.4% ALP sophomore Maylands 1981 59.0% 54.1% 4.9% ALP sophomore Cockburn 1951 59.6% 55.2% 4.4% ALP incumbent Ocean Reef 2374 45.6% 41.6% 4.0% LIB sophomore Jandakot 2254 48.2% 44.4% 3.8% LIB sophomore Armadale 1406 64.8% 61.6% 3.2% ALP incumbent Mindarie 1796 58.5% 55.4% 3.1% ALP incumbent Willagee 1712 64.6% 62.3% 2.3% ALP incumbent Victoria Park 1875 59.0% 57.2% 1.8% ALP incumbent Scarborough 2319 44.8% 44.0% 0.8% LIB sophomore South Perth 2437 35.7% 35.1% 0.6% LIB incumbent Cannington 1521 59.0% 58.7% 0.4% ALP sophomore Darling Range 2028 44.4% 44.1% 0.3% LIB incumbent Hillarys 2331 38.6% 38.8% -0.1% LIB incumbent Gosnells 1488 55.5% 56.0% -0.5% ALP sophomore Mount Lawley 2079 47.8% 48.9% -1.1% LIB sophomore Bateman 2258 38.6% 39.7% -1.1% LIB vacancy Belmont 1713 56.7% 58.2% -1.5% ALP vacancy Morley 1642 49.1% 50.9% -1.7% LIB sophomore Rockingham 1474 60.6% 62.4% -1.7% ALP incumbent Fremantle 2156 62.0% 63.8% -1.7% ALP vacancy Wanneroo 2016 49.3% 51.1% -1.8% LIB sophomore Forrestfield 1757 50.2% 52.2% -2.0% ALP sophomore Southern River 2152 48.4% 50.3% -2.0% LIB sophomore Riverton 2033 49.8% 52.2% -2.4% LIB sophomore Bassendean 1604 60.3% 62.8% -2.4% ALP vacancy Joondalup 1908 53.5% 56.1% -2.6% ALP incumbent Midland 1655 58.3% 61.2% -2.9% ALP incumbent Kalamunda 1871 43.7% 46.7% -3.0% LIB incumbent Cottesloe 2871 30.6% 33.9% -3.3% LIB incumbent Swan Hills 2011 46.5% 49.9% -3.5% LIB sophomore Girrawheen 1384 61.5% 65.1% -3.6% ALP incumbent Carine 2562 35.5% 39.5% -4.0% LIB sophomore Balcatta 1789 52.3% 56.4% -4.1% ALP vacancy Kingsley 2170 45.5% 50.8% -5.3% LIB sophomore
As a basis for analysis this is far from foolproof, as in every case the result would have been influenced by multiple factors outside the model. Nonetheless, it hopefully offers a few hints where parties do or don’t have room to improve. Labor’s six best results were achieved in seats where the Liberals did very little campaigning as they recognised them as safe for Labor, so it might then be thought notable that they are putting considerable effort into two of them (West Swan and Perth) this time. There’s no corresponding pattern at the other end of the table, although Labor did abandon Kingsley very early in the 2008 campaign after recognising it as a lost cause. The two seats which would have intuitively been expected to have been near the bottom of the table, Mount Lawley and especially Morley, are in fact not far from the middle though I hesitate to read too much into that.
If anyone has any further ideas, I’m all ears.
26 comments on “WA election: modelling the 2008 result”
Thanks William that us great I didn’t previously understand why Labor thought themselves in with a chance in Swan Hills. I knew Alban is a hopeless member who turned his back on his own electorate without any protest and should have a negative sophomore vote – and I knew Radisich was running a real campaign but I had forgotten how poor Labors campaign was last time.
Must still be a long shot but but factoring Frank and Ian’s personal factors plus your ‘missing’ 3.5% from last time one could hope for a third Radisich miracle in Swan Hills for Labor.
I’d take out the Greens vote (it’s a rubbish variable) and look at adding census data. Perhaps the proportion of the adult population in each electorate with a university degree and the average age of the electorate.
I agree the Greens vote is a rubbish variable, but it still hit the mark better than any census variable that I could think of. I’d be very interested to hear suggestions. I tried “no religion”, but there was too high a response in a lot of places I don’t think of as being all that trendy.
I think Peter Brent (Mumble) did a Senate Vote – HOR Vote calculation to measure personal vote strength – maybe you could work that in.
Sorry, rubbish variable was probably a bit harsh. My only defense is that I was a little cranky yesterday.
Have you tried the population density if each district? If the figure isn’t available it wouldn’t be hard to work out. The population and area of each district is usually listed on the WAEC website (been a while since I’ve checked, but I doubt it would have changed).
As I said in my first post, the proportion of the population with a university education (bachelor degree or above) may be more appropriate. It usually correlates with Greens voting and density, and is likely more meaningful than both.
If you have access to some survey data (although this is usually hard to get at the State level) you could also try doing some multilevel modelling, including both individual level data and district level predictors. However, this may be more complicated than its worth.
D-day today with treasury costings due. plus the libs doing a lot in Joondalup.
Treasury costs Metronet at $4.3 billion, which is on balance good news for Labor as they said it would be at $3.8 billion whereas Buswell tried on $6.4 billion. Except, apparently, that the Treasury number is “not finalised”.
I think the treasury figures are great for Labor – they should come out with a comment that estimates are not an exact science and that cost control in large projects is a challenge for govt and the private sector in big projects – but highlight over and over again that they will execute the project well and deliver. The costings should be used to talk about the project.
Gareth Parker of The West reports on Metronet costings:
“Meanwhile, Treasurer and Transport Minister Troy Buswell has admitted that more than 50 per cent of the capital cost of the Liberal Party’s big three election transport promises – the MAX light rail, the airport rail link and the Perth-Darwin Highway – will need to be funded by the Federal Government.”
Like to be a fly on the wall when Albo gets that letter …
It’s interesting to note that our local paper has moved away from the traditional election day endorsement of one particular party to its readers to an approach where they are running a 6 days per week continuous endorsement model. This obviously saves time at the end in trying to think of new and creative ways to tell readers why they should love all things Troy and Colin.
The Sunday Times:
– Editorialises for the Liberals (“(Barnett) has the skill, vision and determination to lead for another four years and The Sunday Times believes he should be given that opportunity”), while throwing more than a few bones to McGowan (who “has proven his leadership credentials”);
– Reports Liberal polling shows Brendon Grylls’ primary vote in Pilbara “could be as high as 46 per cent”, and says the party is hopeful of knocking off Graham Jacobs in Eyre, which I thought looked a bridge too far after Labor preferenced the Liberals there;
– Reports the key targets for the Liberals in the final week will be Forrestfield, Joondalup, Balcatta and Albany, with Kimberley, West Swan and Collie-Preston “the next tier of very winnable seats” (not quite sure what to make of Kimberley, which I thought likely to fall to the Nationals).
Given how terrible the Coalition and Barnett are, according to the ALP, if the result is anything like what is being predicted, who will the ALP blame? The voters? The media? The Federal ALP? Themselves?
[Given how terrible the Coalition and Barnett are, according to the ALP, if the result is anything like what is being predicted, who will the ALP blame? The voters? The media? The Federal ALP? Themselves?]
They will accept the result gracefully, something the Federal Libs could consider in the interests of democracy, and change nothing.
Aren’t they ( the libs) simply going through the marginals in their hopes and estimations and factoring retiring members as chancesfor other seats.
I think West Swan iis safe forALP ditto ColliePreston. Not sure about the Kimberely as you have said.
@14 Whinger and Jokeshot betrayed their conservative base and should never have supported an ALP government. They will be slaughtered at the next election.
[@14 Whinger and Jokeshot betrayed their conservative base and should never have supported an ALP government. They will be slaughtered at the next election.]
Clearly they saw their self sacrifice in the interests of the nation.
According to today’s West. The promise of a rapid transit bus service for ellenbrook and surrounds to make up for the broken promise of the rail line has itself been broken.
This should go down well with the residents of Ellenbrook etc
[According to today’s West. The promise of a rapid transit bus service for ellenbrook and surrounds to make up for the broken promise of the rail line has itself been broken.
This should go down well with the residents of Ellenbrook etc]
Would love to know if they are giving up on West Swan or have it in the bag. If Labor can’t capitalize on this they can’t capitalize on anything.
It is very disappointing the Labor brand is so poor they don’t seem to be getting traction with a strong, needed vision against tired old incremental candy promises, along with the inevitable fees and charges increases and decrease in the public service and continued decay of public transport from Barnett.
We want Paul
I notice that they are focussing on Balcatta and Joondalup in recent announcements . My sense is that they have given up on WestSwan and perhaps even Swan Hills.
[I notice that they are focussing on Balcatta and Joondalup in recent announcements . My sense is that they have given up on WestSwan and perhaps even Swan Hills.]
I hope you are right, the Libs really don’t deserve any votes in either electorate they have been an absolute disgrace. I can’t believe Alban actually got preselection a second time, preselecting him for a seat they presumed Radisich would retain, and preselecting him for Swan Hills minus Ellenbrook, after seeing his wisdom, ability and courage on display for more than 4 years is beyond me.
They say Labor has problems selecting hacks, and I think we do, but I’d put up our worst hack after 2 bottles of wine and s/he could eat Alban fresh and sober without raising a sweat.
For what its worth, my brother-in-law was polled twice on the weekend and he lives in Mt Lawley. Sounded like internal polling- not a familiar company. Could there be a few worries about Sutherland hanging on. A lot of my well-to-do friends there don’t like him at all!
@22 – very interesting.
Compact Crank, after reading your posts on the subject, I have put a few dollars on Kucera in Mt Lawley…will owe you a beer if the bet comes through for me!
I’ve just returned from having dinner at the ancestral home.
Before dining, an ad for Barnett came on the telly. Part of the pitch was that he was going to keep up the record spend on infrastructure, AND keep taking the fight to Canberra.
My Mum, aged 74, suddenly burst out, “You lying sack of shit. All of that infrastructure depends on getting money from Canberra.”
Never been so proud of her in all my life.
Listening to the Liberal Bullshit ads you got to wonder did Barnett cost the new AFL gift 8 years ahead,have they costed any of there policy’s 8 yr in advance.
Apart from that I keep wondering who is this wonderful Barnett who stands up to Canberra over the GST,he signed up for it,I don,t recall either he or Court saying very much about Canberra as Howard continued to Centralize power.
I think that if the voters are as stupid as they appear he will have Abbott nothing will change including the GST distribution and Barnett will go very quite indeed,still the local media gutless as usual continue to beat the drum for the Libs.