As we all get reacquainted with the madness that is the first week of the new political season, the time is ripe to do a bit of a comprehensive rundown about the actual state of play of our political polling. We’ll start off looking at the trends and finish with an election simulation for the December quarter.
First up, the two party preferred trend might surprise a few folks that take their media polling commentary too seriously – it reminds me of a line from Chicken Run, “the polling flashed before my eyes, and it was really boring”.
Over the 3 months from mid November, nothing has changed at all in the two party preferred status – zip, zilch, nadda. Federal politics has been glued to a 54/46 split for nearly 90 days straight.
The primary votes however are a little more interesting, with some compositional change occurring underneath that rather dull looking straight line.
While the Labor primary continues to recover from its July tanking – albeit at a pace not dissimilar to continental drift over the last few months – Coalition primary support fell to 46% at the end of last year, before bouncing back slightly post Christmas. It’s interesting to ponder whether that is an effective Coalition vote floor under the prevailing dynamics.
Meanwhile, the Greens continued their year long voyage of exploring political life between 11 and 12% public support and the broad “Others” - apart from pollsters having considerable variation in their vote estimates for this rag tag group – appeared to show a continuation of the slow fade that started after their June 2011 highs.
As of last weekend, the actual point estimates of the trends and the changes from the last election look like this:
The government has a 5.4% swing away from them on the primary vote, washing out to a slightly smaller 4.3% swing away from them on the two party preferred. The Coalition has picked up 3.1 points on their primary while the Greens have lost 0.4 points. The broad “Others” have picked up 2.7 since the 2010 election.
Moving on now to December quarter’s election simulation. For those not familiar with it, we grab three months worth of polling from the major pollsters and a few bits of unpublished stuff (usually giving us a pooled sample of around the 13 to 15 thousand mark), break it down by geography (by state first and foremost, but also by region when possible), turn the derived swings from those polling results into probability distributions for each seat (taking account of their sub-state geography) –then test those swings against the current seat margins about a million times with a monte carlo simulation and aggregate the results. We end up with a simulated election that shows us how many seats would have changed were an election held during that period and the results of the election closely resembled the polling.
First up, the state based swings the government found themselves facing in the December quarter:
The Coalition was experiencing a two party preferred swing towards them in all states and territories, and in both capital cities and regional areas. Seeing how that plays out in seat terms with our simulation, we get:
During the December quarter, the polling had the government facing an election outcome of 53 seats in the 150 seat House of Representatives. Zooming in to the tasty bit:
The ALP had a 65% implied probability of winning at least 52 seats, dropping down to 53.1% for winning 53 seats (the most likely outcome) before dropping further to a 42% implied probability of winning at least 54 seats.
While that is pretty dismal for the government by just about any yardstick – it was actually a significant improvement over the September quarter results. It’s worth comparing the two (you’ll have to click to expand this one):
In the September quarter simulation, the government was looking at only 43 seats, while the December quarter showed a 10 seat improvement across the probability spectrum for Labor. We can see where the improvement came from by looking at how the State breakdowns changed over the period.
While the two party preferred only increased by 2.1% nationally for the ALP, they made 3.1% gains in Qld, 3.7% gains in regional Australia and 5.2% gains in South Australia. On the other hand, Victoria was flat and the capital cities only moved by 1.2% over the September quarter to December quarter period.
Worth mentioning is that the ALP is currently sitting 1.1% higher on the two party preferred than they experienced in the December quarter (currently 45.8% as opposed to the 44.7% achieved over the October to December period) – mostly because of the relatively poor October results. So the current trend polling would have them somewhere around 5 or 6 seats better off at the moment than they were during the final 3 months of last year.
But the story at the moment is not so much the relatively poor state of Labor’s electoral prospects based on current polling, but the fact that the two party preferred trend line has been unmoved for around 90 days. I can’t find another example of 90 days of nothing in federal polling going back to the mid 1980’s, even over a Christmas break. Usually you get some movement – a bit here, a bit there. This one – flat as a tack.