Thursday, 15 March 2018

SA-Best Guesses

Alright, it's election day tomorrow. We all know why we're here. Let's do some number crunching.

First up, here is the pendulum after the last boundary redistribution:

This redistribution put four Labor-held seats (Colton, Elder, Mawson and Newland) into the nominally Liberal range. Seats italicised are those that will deserve special consideration later on, either because the incumbent does not match the nominal 2-party margin (the four previous seats and those held by independents) or because they are on The Poll Bludger's list of possible wins for SA-Best. Two by-elections in SA (in the seats of Fisher and Davenport) also mean that applying the swing from 2014 (rather than the by-election year) may be flawed. Davenport already deserves special consideration as a possible SA-Best win; Fisher is no longer a seat. So let's just apply the predicted swing across the board to get us started.

A Swing and a Prayer

The interesting thing about this election is that, compared to 2014, both Labor and Liberal have reduced their primary vote (down 5.8 and 12.8 percentage points respectively, according to Newspoll). This is largely due to the rise of SA-Best--indeed polls have stopped publishing 2 party preferred data.

So in all non-italicised seats (where SA-Best is unlikely to win, and preferences will flow as normal), I have applied a slight swing calculated as follows:
In 2014 the 2pp vote was 47% ALP: 53% LIB
Xenophon votes generally split roughly 60:40 to the Liberals (Source: p.7)
Numbers on Greens votes are harder to find, but lets assume 90:10 to the ALP
'Others' are ignored as unpredictable
Using these ratios the latest polling of: ALP 30; LIB 32; SAB 21; GRN 7
Becomes: ALP 44.3; LIB 45.3
adjusted to sum to 100, this is rounded to: 49:51
And this equates to a 2% swing to the ALP
Applied to all 2-party contests the pendulum then looks something like:

Interestingly, this slight shift to the ALP is nowhere near enough to bring the four re-drawn seats that shifted to the Liberals back to Labor, nor does it change any seat except that it brought the surprise 2010 Lib win in Adelaide back to a tossup. Then again, the margin of error on these polls is around 2 to 3 percentage points, which would put Black and Gibson in doubt too. Let's add them to the list in need of review:

Adelaide, Black, Chaffey, Colton, Davenport, Elder, Finniss, Florey, Frome, Gibson, Giles, Hammond, Hartley, Heysen, Kavel, Mawson, Morialta, Morphett, Mt Gambier, Narungga, Newland, Stuart and Waite.

Holy Pebble-counters, that's a lot!

To have 23 uncertain seats from 47 (literally just under 50%) at this stage is a record for me. Let's look at the independents first:

Florey: Florey is a safe ALP seat on the numbers and by history. The current incumbent, Frances Bedford, was an ALP member until she became an independent last year. The biggest challenge to an independent is getting enough name recognition to beat the major parties, and sometimes being an incumbent is not enough. In Bedford's case, this hurdle appears to have been mounted; a poll in 2017 had her primary vote ahead of the ALP, and I suspect this has only grown with the exodus of support from the major parties.
Predict: IND

Frome: In 2014, Geoff Brock's primary vote almost out-polled Liberals and Labor combined; again, the hurdle of recognition has been beaten, although there may be some backlash against the candidate in the conservative seat for working with Labor.
Predict: IND

Morphet: Duncan McFetridge has had an unfortunate run of luck, first losing his shadow ministry, then losing preselection to run as a Liberal. As a sitting MP, he will have some traction but it will be an uphill battle to keep this staunch Liberal seat:
Predict: LIB

Mt Gambier: Despite controversy surrounding the financial actions of former-Liberal, independent incumbent Troy Bell, there was polling about a month back showing he would easily win the seat and I don't expect this to have changed. This seat was also listed as a potential Xenophon win, but this has been accounted for in the polls.
Predict: IND

Waite: Safe liberal seat, former Liberal leader Martin Hamilton-Smith became an independent shortly after the last election and notoriously assisted the ALP as a minister this term. Some retribution is to be expected here. This seat has also been singled out as a strong chance for SA-Best. Support for Xenophon in the seat during the federal election was around 23.5%, This is less than the primary vote for the ALP in 2014, though no doubt some of that will be eroded to SA-Best. It is therefore likely that SA-Best will beat the ALP, inherit a lot of preferences and may have a shot at Waite. I will tentatively give this seat to SA-Best, though a Liberal victory would not be surprising. My expectations are the Hamilton-Smith preferences will back SA-Best too, as conservatives disillusioned with the Liberal party, but we will have to wait (or Waite) and see...
Predict: SAB

Next, let's look at the other seats where SAB might do well. There are 13 of these, and support for SA-Best is hard to measure from the polling due to their new arrival in the stats. My back-of-the-envelope methods, then, are this:

The federal election was held in July 2016. At that time state polling included SAB support at 16pp. Federal results in these seats were over 23%. Since then, SAB primary vote statewide has improved by 5, or 31%. To be conservative, we will add a flat 5pp to the federal results (by which The Poll Bludger identified these as hot SAB seats) and compare that to the pendulum (ignoring the Davenport by-election) adjusted by the recent polling for the rise of SA-Best (ALP x83.8%; LIB x71.4%).

The test here is to see whether SA-Best can beat at least one major party so it can collect the flow-on preferences. The answer is yes in the case of Chaffey, Finniss, Hammond, Heysen and Kavel (parts of federal Mayo, which elected Xenophon's only lower house candidate in 2016) and Stuart. I will tentatively give these to SA-Best and the others to the major parties. Interestingly, this means Xenophon's own seat of Hartley is given to the LIBs.

Adelaide, Black, Colton and Elder. Just quickly: Adelaide has a strong ALP history; Paul Caica has held Colton since 2002, when Labor first got in, but his primary vote margin over the Libs was 0.1% and 3% 2pp--with the dropping of Labor's popularity and a tough redistribution I'm calling this LIB; Elder has been ALP since 1997, but the redistribution was rough--nominally LIB; Black used to be Mitchell which was all over the place historically so dart-at-a-dartboard this is LIB too.

Final Prediction:


ALP 19; LIB 18; SA-Best 7; IND 3. That's by the numbers, at least. My gut says SA-Best might get 3 seats at most, and the others go to the Libs giving them 22. I also feel the Indpendents and Xenophon will back the Libs to form minority government either way.

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