2016 Federal Election Seats Model: What 2PP Vote Does Labor Need To Win?

Advance Summary

1. This article seeks to model what two-party preferred vote Labor would on average need to win the 2016 federal election, based on known information about personal vote advantages, retirements and optionally state-level federal polling.

2. A simple reading of the Mackerras pendulum projects Labor as requiring about 50.3% 2PP to form government and 50.55% to govern in majority.

3. However, the pendulum is prone to over-predict how many seats a party will gain for a given swing if that party lost many seats at the previous election.

4. The reason for this is that the new personal votes of sitting MPs in marginal seats make them more difficult to defeat.

5. With this considered, my current model estimates that Labor requires a 50.9% two-party preferred for an even chance of forming government at all, or 51.4% for a 50-50 chance of a majority.

6. These numbers are estimates only and it is possible Labor could form government with a slightly lower figure or fail to form government with a slightly higher one.

7. These numbers also don't take into account the possibility of a substantial number of new non-Green crossbenchers in the Lower House, as it is not possible to model the chances of that happening yet.

A New Species Of Strangeness In The West

It's a familiar polling story.  The long-serving government is looking rough around the edges and the Opposition has a moderate but handy polling lead.  The Premier is on the nose and has been rating badly for years, the Opposition Leader is well regarded and leads as preferred Premier.  There are rumours and rustlings, and finally a challenger indicates potential interest in the job, should his/her colleagues so desire it, and says that the current leader can't win the election.  We all know how this story ends.

Only in Western Australia, it's the Opposition Leader, not the Premier, who has been informally challenged - and even more strangely, the putative challenger isn't even in parliament.  In an extension of the Campbell Newman doctrine (in which a new leader can be drafted by the party from outside the parliament in order to take over), it is now possible for someone to raise an interest in the leadership when they:

* aren't in the parliament or serving in any current political role
* have no seat for which they are reasonably assured of preselection
* aren't being drafted by the party's current organisation or the parliamentary party, and whether anyone involved in the drafting is even a member of either isn't totally clear

Strange Times In Queensland Polling

Galaxy Queensland: 52:48 to ALP based on composite preferences
Based on last election preferences 54:46 to ALP
Result based on this poll if election "held now": Easy Labor win (approx 54 ALP, 32 LNP, 2 KAP, 1 Ind)
However, most other polling so far has suggested little change since 2015 election

Update added for Aug-Sep Newspoll (53:47/55:45)

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A new state government has won a remarkable victory, ousting the regime that had thrashed it three years earlier after just one term despite having been almost wiped off the political map.  Six months into its term, and despite a significant scandal that has endangered its already fragile hold on power, its primary vote has been polled at two and a half points above its election result, the Opposition is down a similar amount and the most supportive minor party's share of the third-party vote has improved.  Not the greatest honeymoon in polling history but still, all things considered, pretty good?

Well, supposedly not.  According to reporting (?) of a newly released Galaxy of Queensland state voting intention, the Palaszczuk Government has "stalled", "stagnated", "received no bounce from handing down last month's state budget".  Apparently it "hasn't been much of a honeymoon period [..] in stark contrast to the burgeoning support being enjoyed by governments in southern states".  The Premier's popularity has "failed to prompt any new love for Labor".  Her government "could scrape over the line" but "would rely heavily on votes flowing strongly from preferences".  The government apparently should be concerned that it's been "unable to convince more Queenslanders they're a competent administration" and unless it can prove it is doing something then "the patience voters have shown will run out".

What is going on here?  What's going on is what happens when you take the Courier-Mail's oft-noted love of curious poll-spinning and combine it with an understandable, but nonetheless unusual, preferencing practice.  This article looks at how the Palaszczuk government is really going in terms of known public polling.

New South Wales: March Poll Roundup And Seat Modelling

(For the final week's article go here - note added 26 Mar because this one for whatever reason is still getting more hits!)

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Current aggregate (updated March 19): Coalition 44.6 Labor 35.3 Greens 10.2 Other 10.0
2PP Estimate: 53.3% to Coalition (54.6 by last election preferences)
Current median seat projection: Coalition 52 Labor 37 Others 4

Summary:

1. Recent polling shows the Coalition continuing to maintain a primary vote lead of at least eight points over Labor.

2. Recent polling also shows that while preferencing patterns among minor party voters may change, they are unlikely to change by nearly as much as in Queensland.

3. However, current polling when translated to seat projections suggests only a small Coalition majority.

4. There is more uncertainty than normal in translating the Coalition's current lead to seat results, and for this reason current voting intention levels do not quite assure the Coalition of victory. 

5. Any narrowing of voting intention from this point would make a hung parliament significantly more likely.

New South Wales Roundup: Is Even This A Bridge Too Far?

Time to kick off some NSW state election analysis, much of it in broad and general terms.  I haven't done the usual seat-modelling yet; that will follow in a week or two.

Feds Will Destroy Everything

A common theme on this website is the massive influence of which party holds power federally on state elections.  While this impact is not obvious in every election, and isn't even present in a few, there is a long-established pattern that is the very first thing anybody looking at state elections needs to know.  Once a party has been in government federally for any length of time at all, it starts tending to shed seats in state elections.  This process continues until it has lost most if not all of the states, and not long after that it will probably lose federally as well.  A new federal government comes in with massive majorities in many states, and then starts losing those.  Rinse and repeat.

Since the Liberal-National Coalition came to power federally it has faced four state elections, winning only Tasmania where an ancient Labor government could not escape retribution for a deeply disliked coalition with the Greens.  This happened while the federal government was still relatively new.  However, the Coalition has also lost office in Victoria and Queensland and failed to win in South Australia.  The Victorian result was no surprise, SA was a vaguely forgiveable case of electoral geography 1, 2PP vote 0, but the Queensland result was an earthquake.  The government that had won office with a record majority only three years earlier, almost wiping its predecessor out of Parliament, was sent packing (by one seat) with a 14% swing against it.  The LNP's aggressive and divisive born-to-rule approach in office had done it no favours but things would have been very different had Julia Gillard still been in the Lodge.

With declining levels of rusted-on adherence to both major parties, there's just no such thing any more as a win so big that you cannot possibly waste it in a single term.  That applies especially when the prevailing wind from Canberra is not in a party's favour.  In fact, the idea that a seat margin at one election determines the seat margin at the next is overrated anyway - what winning big really does is just gives a party a lot of seats in which it has new personal votes.  It turns out that in NSW even that doesn't apply much this time around.  So is there such a thing as an election that is too hard to lose, or is nothing actually safe in state politics anymore?

Queensland: Final Results And Poll Accuracy

The final results of the Queensland election are out.  Three years after being reduced to something that could fit in a Tarago, the ALP has won office in minority by what may just be a single seat.  (Katter's Australian Party spent so long milking press cover over their agonising decision on who to support that in the end government was formed without waiting for their decision.)  In one amazing echo, Peter Wellington gives Labor the numbers exactly as he did for a few months seventeen years ago.  In another, Antony Green estimates the 2PP at 50.9 to Labor, so virtually the same as 2009.  It is much as if 2012 just never happened.

There are two competing baseline 2PPs for the 2012 election, one of 62.8% to LNP and one of 63.1% to LNP, mainly depending on how you treat Gladstone.  On the latter the swing comes out at about 14%, on the former slightly less.  There may be slight revisions to the 2PP estimate for this election too, but in any case the swing was not much short of 14%, if at all.

In fact, the LNP were a trifle lucky to get as close to hanging on in seat terms as they did.  If the numbers are plugged into the ABC calculator (and crossbench defector/retiree seats assigned as they fell), it suggests 48-38-3 to Labor.  My own seat model, taking personal vote effects and probabilities into account, suggests 45-41-3 to Labor for that 2PP.  The LNP managed one more mainly because they had more very narrow seat wins.

Victorian State Election: Late October Polls And Seat Model

2PP aggregate of recent Victorian state polling:  ALP leads 52.6-47.4

"Nowcast" seat estimate based on this 2PP: ALP 48 Coalition 40

After a week buried deep in the Hobart City Council count I've finally found time to get stuck into the Victorian state election.  This thread starts with a roundup of recent polling, then goes into the early version of a seat-probability model similar to my one that picked 93% of seats correctly at the 2013 federal election.  The federal election version was whipped up very quickly in the shadows of the post; I have much more time to work on this one so it will probably do much worse.

The new polls

Six polls have been released in the last week or so, by a range of methods.  Two of them have had suspiciously high Green votes.  For the Morgan SMS poll it also had a suspiciously high Green vote in late September, so I'll assume this is systematic.  The Ipsos poll is the first of its kind, and their federal poll published today hasn't shown any skew to the Greens, so I'm assuming for now that their methods are no more prone to green skew than the four more established pollsters.  Anyway in aggregating these six polls at the bottom I've pinged the Greens 0.9 of a point in every poll except Morgan SMS, for which I've applied a very lenient deduction of four.  For more information on this decision see my new blog header.