Second wave of post-Budget polling

Overnight two more polls were published:

• In the Fairfax media, the Ipsos poll had the two party preferred result at 50/50. This is the best poll result for the Coalition since Newspoll of 4-6 April 2014 had the Coaltion on 51 per cent. The Ipsos poll was up four points for the Coalition on the April 2015 Ipsos poll.
• In the Australian, Newspoll had the Coalition on 47 per cent, two-party preferred, which was down one percentage point on the previous Newspoll at the start of May.

Plugging these numbers into the Bayesian model yields:

The latest Ipsos poll is substantially adjusted in the Bayesian model.

Where there is remarkable agreement is in respect of the Prime Minister's recovery in the attitudinal polling.

In contrast, happiness with the Leader of the Opposition is largely unchanged.

First batch of post budget polling

It is the weekend after the Federal Budget and the blizzard of post Budget polling has started. There is a venerable tradition in Australian politics of wall-to-wall polling in the week that follows the Budget.

Mark Graph's first law of polling analysis is that most Budgets are meaningless events in the lives of most punters. Budgets have minimal (if any) impact on week-to-week movements in the national voting intention (particularly at the time of the Budget). Where they do have impact, measures that hurt are more likely to have an impact than measures that help. Furthermore, if a Budget measure does have an impact on voting intention, that impact is typically manifest closer to the time of implementation (when it actually hurts) than at the time of announcement.

Mark's second law: breathless reporting, where every micro-movement in the polls is over analysed, follows the Budget polling. In the melee, noise and signal become confused: one media outlet will proclaim the resurrection of the government and another will declare its Armageddon - all in the same week. The reporting of opinion polls in the week following the Budget is often little more than an exercise in intellectual masturbation for the titillation of those living inside the beltway.

Now that I have got that off my chest, let's look at the polls:

• ReachTEL has the national two-party preferred voting intention at 47-53 in Labor's favour. This is a movement of one percentage point in the government's favour since 23 April.
• Galaxy has the national two-party preferred voting intention at 48-52 in Labor's favour. This is a five percentage movement in the government's favour since February 2015.

Before moving to the charts, I need to acknowledge a few things. I have added some early 2014 data that I had missed, including the ACNielsen polling data before it ceased political polling. Because I use a sum-to-zero constraint in my model, these charts are not directly comparable with the earlier charts as a result.

In short, the government's fortunes continue to improve, but at a very slow pace. The government is still some distance from looking competitive were an election called at this time. All-in-all, there is not much to see in the post-Budget opinion polling.

Update

I shifted the graph production process from ggplot in R to matplotlib in python. Of necessity, this saw some analytical tasks move from R to python. In the process, it became clear that the LOWESS (localised regression) package in python statsmodels was not as robust as the conceptually similar LOESS package under R. For comparison, the first two of the remaining charts were produced in R. The subsequent charts were produced in python. I still run the Bayesian model in R/JAGS. However, I now export the model output data to python for chart production.

Correction

On the annotated charts, the last result was rounded to zero decimal places. This has been corrected to round to one decimal place.

Comparison of Attitudinal Polling

Four of the polling houses have asked questions on the performance of the Prime Minister and the Leader of the Opposition. ACNielsen and Ipsos asked if you approve/disapprove of the their performance. Newspoll asked whether you are satisfied or dissatisfied with the way they are doing their job. And ReachTEL gave you a five-point Likert scale on which to grade their performance ranging across very good, good, satisfactory, poor and very poor.

While the questions and methods differ a little, each is essentially asking respondents if they are happy or unhappy with the performance of the Prime Minister and Leader of the Opposition. While the levels of happiness may differ between polling houses, the timing of the ups-and-downs are remarkably consistent between the polling houses. The levels of unhappiness are more closely aligned.

On the happiness and unhappiness maps, the Prime Minister has been on a roller coaster. Newspoll particularly has happiness on the improve at the moment for the Prime Minister. All of of the polls report that unhappiness has declined since the Prince Phillip knighthood and leadership spill motion (late January/early February 2015).

It will be interesting to see whether this latest movement in happiness will translate into a more substantial improvement in two-party preferred voting intention for the government.

For the Leader of the Opposition, these attitudinal maps have been relatively flat for many months. Nonetheless, there is a hint that things might be declining a just little in the last three months.

Update

A couple of extra charts:

Not a lot to report

Two new polls this week: Morgan at 46.5 per cent for the Coalition (down 0.5 percentage points) and Newspoll (perhaps the last Newspoll as we know it) at 48 per cent for the Coalition (down 1 percentage point).

When I feed the latest data to the Bayesian aggregator, we can see a very slow improvement over the past nine weeks (less than one tenth of one percentage point per week - an improvement of 0.72 percentage points over the nine weeks).

Steady as she goes

There is not much to report since the last fortnight. The Bayesian model has been a flat line now for eight weeks, deep in catastrophic loss territory for the Coalition.

The LOESS model has come back into line with the Bayesian model.

Aggregated polling update

Another set of noisy polls - moving in different directions - giving different messages on the state of the nation's voting intentions:

• Newspoll over the weekend is unchanged on three weeks ago with the government on 49 per cent.
• Ispsos over the weekend has the government down three points on the end of February at 46 per cent.
• ReachTEL at the end of March, had the government up one point on the beginning of February at 46 per cent.
• Morgan at the start of April had the government up three points on the middle of March at 47 percent.

Using the Bayesian model to peer through the polling noise and house effects suggests there has been little movement for six weeks in the government's polling fortunes.

If we adjust the recent polls for house effects, an interesting pattern emerges. Very few of the recent polls are close to the median model prediction. A cluster of adjusted polls sees the government on 48.5 to  49 per cent. Another cluster of adjusted polls sees the government on the very uncompetitive 44.5 to 45.5 per cent. I am not sure that this is meaningful, beyond being cautious and acknowledging that the polling seems quite volatile at the moment.

I also use a less-sophisticated localised regression (LOESS) as a cross check. The end-points in the LOESS regression are very volatile, and the technique is overly sensitive to endpoints and outliers. At the moment, the LOESS regression is telling a different story to the Bayesian model. However, my experience is that the LOESS model usually comes into line with the Bayesian model as more data points are added. I would be cautious with a recovery narrative based solely on the LOESS regression. Noting the Bayesian bifurcation above, a recovery narrative for the government over recent weeks cannot be ruled out; but nor can it be proclaimed as absolute fact. All we can do is patiently wait for more data points. 

Poll update

The polls are noisy and contradictory this fortnight. At 49-51 in Labor's favour, today's Newspoll is the best result for the Coalition since September 2014.  It represents a four point move towards the Coalition over the previous fortnight. However, tempering the celebrations in the Coalition's ranks was yesterday's Morgan poll at 44-56 in Labor's favour. This was a 2.5 percentage point move towards Labor over the previous Morgan poll.

Let's look at the charts. We will start with the polling house-by-house line chart. You will note we have not seen a national Galaxy or ReachTEL poll for some time, as they focus on the NSW election.

Plugging the latest numbers into the Bayesian model, suggests the Coalition's fortunes are improving slowly, but there is a way to go before the Coalition would be in there with a chance at the next election. Nonetheless, the 2.2 percentage point improvement since the spill motion just six weeks ago is not to be sneezed at.

The LOESS model has come back into line with the Bayesian model.

Polling update

This week's Newspoll was unkind to the Coalition (but not as bad as the early February poll). The Morgan poll this week was the most favourable from the polling house since late November 2014.

Collectively, through the Bayesian model, the polls are suggesting a one and a half percentage point recovery for the Coalition since the Prince Philip purple patch at the beginning of February. But they are also suggesting that the Coalition's recovery momentum is stalling.The Coalition could not win an election with these numbers.

February poll update

Since the spill motion on 9 February, the polls have improved for the Coalition. If an election was held now, it would still be a thumping loss, just not as thumping as early February.

I should point out that LOESS regressions can be overly influenced by outliers, especially at the end-points. We will need to see more polls to know whether the recent change in voting intention is as dramatic as that suggested by the previous chart.