Category Archives: politics

Polls apart on climate change

Regular Stubborn Mule guest James Glover (@zebra) turns his statistical expertise on some apparently contradictory polls gauging opinions on climate change.

Two polls came out today on the question of whether people believed climate change is real and if so whether it is caused by human activity. The first was a Newspoll published in The Australian and the second was by Essential Media and was commented upon by Essential’s Peter Lewis on ABC’s The Drum. Intriguingly, the Newspoll suggests 73% of Australians believe in climate change with a significant human contribution (so called Anthropogenic Global Warming or AGW). Now The Australian has copped a bit of flak lately for its alleged anti-climate change agenda, but leaving that aside this poll suggests that AGW should be practically a closed book politically as an overwhelming majority believe in it. Essential Media describes themselves as a research tool for progressive political campaigns. Essential’s poll indicates that only 45% of people believe in climate change caused by human activity. In the accepted narrative of such things the results would have been around the other way and the tweetsphere would be apoplectic accusing The Australian and News Corp of once again distorting Newspoll results for their own right-wing political agenda. So what is happening here?

First a note on sampling error. Essential polled 1896 people while Newspoll contacted 1,123 people. For polls where the expected split is approximately 50% a good rule of thumb for margin of error (MoE) is 1/√sample size. In the two polls here this gives MoEs of 2.2% and 3.0% respectively. MoE represents two standard deviations from the sample average so differences of 25% are extremely unlikely (like 10-10 probability unlikely) to be explained by a unfortunate random choice of sample from the general population.

The most likely explanation is that one or both of these polls suffer from an underlying sampling bias. This would be easy enough to generate artificially—just poll people in Newtown if you want to get more people who believe in AGW or in Bob Katter’s seat for the opposite result (is this a little glib? Maybe, but you know I am right). But legitimate pollsters like Essential and Newspoll rely on the rigour of their sampling technique. Especially as every time you publish a controversial result, a large section of the population who disagree with it will accuse you of bias. There are a number of techniques to reduce bias—one is to ask coquestions whose population statistics are well accepted. For example if in your poll you found that 46% of the respondents were female and 54% were male you can readjust the result to reflect the actual population average of 51:49. I assume both polling organisations follow standard methodologies to minimise bias. Often though their actual methodologies are proprietary so question marks remain. A famous political polling agency was well know to always come up with polling results that reflected the political opinions of its founder after “adjustment for bias”.

Some indication that there isn’t an overwhelming bias are some additional questions about voting intention. Here are the results:

Essential Newspoll
Coalition 45% 41%
Labor 38% 34%
Green 11% 14%
Other 6% 11%

I would have to say that the differences in the numbers are on the borderline of being consistent with the MoEs I estimated. In any event the Newspoll which has a higher number believing in AGW has less Coalition voters (though about the same Labor+Green votes). It seems unlikely that the votes for Independents and other alone could account for the 28% difference in the polls on the question of AGW.

So that leaves us with the polls themselves. I have assumed so far that they asked the same questions, but there are major differences. Here are the actual questions and results:


Climate change is happening and is caused by human activity 45%
We are just witnessing a normal fluctuation in the Earth’s climate 36%
Don’t know 19%


No climate change 18%
Climate change solely caused by human activity 18%
Climate change partly caused by human activity 55%
Climate change not caused by human activity 3%
Believe in climate change but don’t know cause 2%
Don’t know if climate change is real 5%

Now what appears at first to be a headline difference between the polls is more subtle. It is quite hard (I tried) to map the answers between them exactly to compare the results. For example Essential doesn’t ask if the respondents directly if they don’t believe in climate change at all (18% in Newspoll) so presumably the climate skeptics get lumped under “Don’t know” (19%) which will also include those who believe in climate change but don’t know if it is caused by human activity or don’t know if climate change is real. That Newspoll total of “don’t knows” and skeptics is 23%, a bit higher than Essentials “Don’t know” of 19% but within the MoEs as reflected by the voting intention results.

However we can try to compare the two main results which boil down to “Believe climate change is real and human activity is significantly affecting it” of 73% (Newspoll’s headline result combining “solely” and “partly” caused by human activity) vs Essential’s “Climate change is happening and is caused by human activity” of 45%. The difference appears huge. The only thing I can think to explain this is that when not offered the choice of “solely” vs “partly” caused by human activity the Essential respondents threw their lot in with “caused by a normal fluctuation in the Earth’s climate”. In other words the results are consistent if most people who believe that “climate change is real” but don’t believe it is “solely caused by human activity” believe it is “partly caused by human activity” but mostly due to “natural fluctuations in the Earth’s climate”.

What is clear here is that the wording of polls is important and that both polls failed to tease out the subtle distinctions in people’s views on climate change (though Newspoll did a better job of this than Essential). There are also question marks about the sampling bias as shown in the voting intention results. But the headlines of both polls will superficially look like totally different results. And that is a problem when the results are used to support political rather than scientific views on anthropogenic global warming as fact or fiction.

A Delicate Balance

3-way BalanceEver since Julia Gillard managed to wangle the support of two of the three country independents and scrape through to a second term in government, speculation has focused on how long the arrangement can last…and not only in the media but also on the Mule Stable.

Challenging though the road ahead may be for the new government, with so many different interests to juggle, I am of the view that Labor will do whatever they can to hold on to power. Even if they are unable to pass “crucial” legislation, they would be very unlikely to go to the polls early lest they lose the election. After all, if they did not have the courage to trigger a double dissolution when they failed to pass emissions trading legislation to combat the “greatest moral challenge of our time”, it is hard to see what issue could be important enough to them to jeopardise their power.

As for the independents, another election would risk their own new-found power. Furthermore, in siding with Labor they have not really promised very much. All they are committing to is to pass supply and to support the government in the event that no confidence motions are brought against it. On each and every particular piece of legislation they are free to horse-trade once more and potentially vote against the government. Also, as Bob Brown recently pointed out, there is nothing to stop the independents and the Greens backing legislation initiatives brought forward by the Liberals. So there really is no good reason for the independents to withdraw their support from Labor.

Without the numbers, the Liberals and Nationals are powerless to bring on an early election. So, this unlikely new coalition government is likely to be here to stay. The only scenario I can see that could undo Labor is a by-election. If one of the MPs supporting Labor were to fall under a bus, retire, disgrace themselves and resign or in some other way leave the Parliament, the Liberals would have the chance to win the by-election and chance the numbers on the floor. Failing that, I would expect to see Labor ruling for a full term.

What do you think? While it may take some time to see the result, this seems like a good opportunity for another poll on the Mule, so have your say!


More Informality

Yesterday’s post on informal votes generated a lot of questions, both on and off the blog. One commenter was interested in understanding why there was so much variability in informal votes in New South Wales. It is a good question, and one I do not have an answer to. Presumably demographic differences across electorates (such as varying facility with reading English among non-native speakers) would come into play. But this still leaves open the question as to why the swing in informal votes varies so much across New South Wales. I will have to leave it to you to explore: the table below has the informal vote in all 48 New South Wales seats for your perusal. Let me know if you have any theories!

Division IDDivisionInformal (%)Informal Swing (%)
127Kingsford Smith8.232.92
137North Sydney4.620.9
135New England3.60.63

An email correspondent asked whether it was in fact the 2007 election that was anomalous rather than the 2010 election, so I have also compared the 2010 informal vote to the 2004 election. Interestingly, the uptick in informal votes from 2004 to 2010 is indeed smaller. In fact, Western Australia had a lower rate of informal votes in this election than in 2004. New South Wales still shows significant increases in informal votes in a number of electorates, which helps drive a national trend. Overall, compared to 2004 there does still seem to be something going on with informal votes, but the effect is certainly less marked.

Informal Votes: 2010 vs 2004

I also received various questions about whether correlations could be seen between informal votes and Green votes, whether the increase in informal votes was greater in more marginal seats and so on. Unfortunately, as yet my data mining has not revealed anything of substance. Here, for example, is the increase in the rate of informal votes versus the absolute two-party preferred margin. The regression lines show no simple relationship.

Informal vs 2PP

Informal Vote versus Two-Party Preferred Margin

Comparing Green votes to informal votes is just as unenlightening. That, at least, seems to make sense. While it is reasonable to consider some of the Green vote as a protest vote and some of the informal votes likewise as a protest vote, it may be that in some electorates more voters were inclined to protest by voting Green than informal, or vice versa. This would mean that there would be negligible correlation between the Green and informal swings at the division level.

So, despite my efforts, I am yet to squeeze further insight from the data. Of course I remain open to further suggestions! If you would like to do your own analysis, the current 2010 data is available from the AEC as is past data.

UPDATE: If you sort the table at the top by informal vote, you’ll see that the two electorates with the lowest rates of informal voting were New England and Lyne, the seats of the independents Tony Windsor and Rob Oakeshott respectively!

Also, here is a national table of informal votes (just to avoid being to NSW-centric).

Dress: Informal

While Australia still waits to see which party will manage to scrape into power, the Australian Electoral Commission (AEC) has announced an investigation into the unusually high rate of informal votes. Veteran ABC analyst Antony Green observed that the rate of informal votes was the highest since 1984. Some are attributing the rise to the “Latham effect” following the exhortation by former Labor leader now professional provocateur, Mark Latham, that voters should spoil their ballots to thumb their noses at both major parties.

It will be interesting to see what conclusions the AEC draws, but there is no doubt that the informal votes in this election were significant.There are more votes to be counted and the trends in postal votes may differ somewhat from votes cast in person, but enough of the votes are in to get a reasonable picture of what has been going on. The figures here are based on the AEC data for the House of Representatives as at 23 August 2010. Informal votes rose in every state from the rate seen in the 2007 election, increasing by a margin of between 1.0% and 2.4%.

State 2007 2010 Change

Informal Votes by State (%)

One way to visualize the changes is to plot the informal vote rate in 2010 against that of 2007. The chart below does this at a state level and also adds in a 45 degree line. Points falling above this line (as they all do) show an increase from 2007 to 2010, while points below the line would indicate a decrease.

Informal Votes by State

Aggregating to a state level hides a lot of the interesting detail and can be misleading. For example, the ACT shows the biggest increase in informal votes, but with only two electorates, these figures have less statistical value. A more interesting picture emerges when the changes are shown by division. The chart below groups the changes by state, but plots points for each division*. Once again, 45 degree lines provide a guide as to whether informal voting rates increased or decreased.

Informals by Division (State and National)

Leaping out from this picture is the extraordinarily high rate of informal votes in some divisions in New South Wales. It is also striking that the rate of informal votes has increased in almost every division. At this point, there are only 4 divisions in the whole country (one in Victoria and three in New South Wales) to see the rate of informal votes drop.

It is hard to escape the conclusion that the increase in informal votes reflects a protest vote arising from deep voter dissatisfaction with both major parties. The Greens are pleased with the “Greenslide” they have experienced, but some of their success is likely to amount to the same voter protest, only expressed another way, rather than a permanent shift in commitment to the Greens.

* For the purists, there were changes to electorates between elections, and the chart only shows divisions which existed in both 2007 and 2010. Given changes to boundaries, some of these electorates are, strictly speaking, no longer perfectly comparable, but they have been plotted regardless.

Recognise this?

Last night I was watching the Chaser’s Yes We Canberra (only a day late), and jumped out of my chair when I saw Craig Reucassel corner Tony Abbott to challenge him about his obsession with reducing Government debt. Have a look at this to see why!

Here is the post referred to in the video.

UPDATE: here’s a tweet from Craig on the topic of attribution (or lack thereof):

Infrastructure Bonds

With Australia’s Federal election looming, the opposition has today proudly announced a new policy to fund infrastructure without actually increasing Government debt! What are we to make of this?

It’s hard to determine the details from a media announcement, but based on the text posted by Peter Martin on his blog, it would seem that the idea is to provide tax incentives for entities other than the Federal Government to borrow to fund infrastructure:

Private infrastructure operators and State and Local Governments will be eligible to apply for the concessional treatment.

The way the scheme would seem to work is that eligible projects could issue bonds and investors would receive a tax rebate amounting to 10% of the interest on the bond. So, if you received a $100 interest payment and your earning put you in the top marginal tax bracket, you would pay $45 in tax. Under this scheme, you would only pay $35 in tax.

So, the cost to the Federal Government would simply be forgone tax revenue (and this would be capped at $150 million per annum) and the Opposition believes that the program could support up to $20 billion in infrastructure financing. Presumably, investors currently buying plasma TVs would rush to buy these bonds instead.

Seems like a neat trick, but I have a number of reservations about the scheme.

First, I have argued in the past that the near-hysterical concern about Government debt is overdone. For a start, Government debt in Australia is far lower than in other developed countries around the world. More importantly, the facile analogy that compares Government finance to that of a household budget does not stand up for one very important reason: unlike you or me, the Government is the monopoly issuer of Australian dollars. This changes the game and breaks the analogy utterly.

Second, the opposition’s policy would still involve raising significant amounts of debt, just not issued by the Federal Government. If that debt is all incurred instead by State Governments, should that really be a cause for celebration? After all, unlike the Commonwealth, State Governments do not control issuance of currency, so they really could go bankrupt and indeed, recent history has shown that many of the State Governments are loath to increase their debt levels too significantly for fear of having their credit rating downgraded. What if the borrowers are in the private sector? Well, that would be worse still! Back in March I updated my chart showing private and government sector debt. The debt level we should all be worried about in Australia is private sector debt, which is far higher than government sector debt.

History of Government and Private Sector Debt levels

Third, infrastructure bonds have form. Back in the 90s, the then Labor government introduced an infrastructure bond scheme which also featured tax incentives. Of course, it did not take long for clever investment bankers to work out how to surgically isolate the tax benefit so that wealthy individuals could take advantage of the concession without actually taking on any investment risk. In the end, the whole scheme was shut down, although some of the transactions that were done still survive today. I would expect exactly the same thing to happen with this policy. Any special tax treatment is always a red rag to the tax expert bull.

So, it may sound clever, but to me it does not seem to be sound policy.

Broadband Poll

As a follow up to our guest post on the numbers behind Labor’s broadband policy, here is a quick poll to see whose policy you prefer. Let us know what you think!

Labor’s National Broadband Network – Less than $10/month

Our regular guest contributor James Glover (aka @zebra) returns today with a look at the numbers behind the National Broadband Network. He asks: do you think it would be value for money?

The Labor Government’s proposed National Broadband Network (NBN) has many things to recommend it, not least speeds of up to 1GB/s (currently I am on 10Mb/s for ADSL; theoretical speeds of 24MB/s on ADSL2+ and 100MB/s on VDSL are also soon to be widely available, though the reality is dependent on many variables such as distance from an exchange). It would revolutionise the way we communicate as the higher bandwidth would allow not just interactive entertainment and fast downloads, but genuinely accessible cloud applications that really felt like they sat on your computer…and of course dishwashers waking up at 3.00am to negotiate the best electricity price. I doubt whether anybody on either side of politics would disagree that, in a perfect world, this is all desirable. But like all utopias, it comes at a cost and that is where the real divergence between the Labor Party and the Coalition’s broadband policies exists. I hope to cast some light on this cost argument using the power of the Time Value of Money, in particular calculating the real cost to you on a monthly basis so you can compare it with your existing broadband cost.

Labor wants an all-connecting fibre optic network (with subsidised satellite to cover really remote areas) that will cost an estimated $46bn. The Coalition wants a more modest effort: a fibre optic “backbone” network that uses existing copper wiring in urban areas and relies on market competition to pay for further improvements. It is estimated to cost about $8bn plus later commercial costs. Both of these figures seem extraordinarily high. How to decide if it is really worth it? Well if I told you that Labor’s NBN would cost you $10 per month would that sound too high? After all that only includes the infrastructure cost, not the access cost via an ISP. But most of us don’t pay upfront for our broadband or mobile (cell) phone bills, we pay monthly. The Coalition’s figure of $8bn works out at less than $2/month each (for those so inclined, you can read the details behind these figures). But it doesn’t include any additional costs charged by commercial companies building additional infrastructure. It also only claims to provide “peak speeds” of 10Mb/s which I already get on my ADSL+.

Is $10/month a lot of money? Or $2/month for that matter? It obviously depends on what your income is and how much you are currently prepared to pay for broadband. My broadband plan costs $50 for 120GB/month. I also live in a one-person household. It doesn’t sound much to me, but all those $10/month costs add up to the thousands we pay in tax each year. There’s no point paying more for little for no benefit. Of course it’s not going to be charged directly, but through increased taxes (or decreased services). I estimate $10/month to represent an average increase in the tax rate of about 0.5%. This seems reasonable to me. After all, if in 2020 a businessperson (or BusinessBot2020) came to Australia and found our broadband to be the equivalent of dial-up today, they’d hardly be impressed enough to invest in a technology business. Of course, by 2020 with super-fast broadband we should really be able to do most business remotely, right? But we’ve been saying that since the invention of the telephone.

So I’m for the Government’s NBN plan…but what do you think?

Update: I have since writing this post changed my mind based on readers’ comments and some research. It appears that many of the benefits of the NBN are available already on ADSL2+,  VDSL and 4G and the Coalition’s more modest plan to build a fibre-optic network backbone might be sufficient. There is also the question of whether a Government entity is best placed to oversee such a large scale project – it’s not like Peter Garrett is going to personally project manage the NBN but Governments in general are not (IMO) best placed to predict and respond to consumer demand. But I accept there are strong feelings on both sides. Sometimes that bright shiny thing in your vision is a light on a hill and sometimes it’s a white elephant blocking your view.

UPDATE: Let us know what you think by voting in this broadband poll.

When will Julia go to the polls?

After taking Kevin Rudd’s scalp and now having done a deal with the miners, Australia’s new prime minister, Julia Gillard, is widely expected to call an early poll. The question is, when will the election be held?

As usual, my first inclination is to dig into the historical data. Looking at all of the Federal elections since Federation, December is far and away the most popular month for a poll. Although the election does not even have to be held this year, December is sufficiently far into the future that it fails to qualify as an early election. Unless the bounce Gillard has experienced in opinion polls proves to be extraordinarily short-lived, we should be looking at a somewhat earlier date. Interestingly, both July and August have only seen one election. On the admittedly spurious grounds of historical precedent, September would be a better bet.

Australian Federal Elections by month

But what of other sources of information? At the time of writing, the shortest odds from SportingBet were on August 7. In my own rather modest poll, August is also proving the most tipped month (it’s not too late to vote in the poll…just make your selection in the form below). No-one has voted for a date in July and I am inclined to agree that that is really a bit soon. Nevertheless SportingBet is still showing odds (admittedly long ones) for 31st July.

In a bid for contrarian status, I will diverge from both the bookies and voters in my poll and will tip a September election. But which date? History is not much help there. Of the four September elections in the past, there has been one on the 1st, 3rd, 4th and 5th Saturday of the month (1914, 1934, 1940 and 1946 respectively). So, I will veer as close as possible to the people’s choice of August, while still tipping September and predict that the election will be on Saturday 4th September. In choosing that date, I have not been swayed by the fact that the fourth Saturday of the month has been the most popular historically, other than to nominate 28th August as my fall-back selection.

Since I will most likely be wrong and you probably disagree with me, make sure to vote!

RSPT RIP – Long Live the MRRT

In the third in a series of guest posts on the subject of Australian mining tax, Zebra (James Glover) considers the changes to the proposed tax the new prime minister, Julia Gillard, has negotiated with miners.

The Govt has announced a replacement for the RSPT discussed in earlier posts to a Mineral Resources Rent Tax (MRRT). The principle differences are the tax rate – 30% and a change in the deduction. For established mines it is now based on market value depreciated over 25 years and the uplift rate is 12% not 5%. In addition there is a 25% deduction from earnings upfront which makes the base rate of tax 22.5% rather than 40%.

This post replaces an earlier one I put up about the MRRT in which I erroneously assumed that the opt-in about using the market value of assets applied in the way I proposed in my second post. The key statement here is:

“Miners may elect to use the book or market value as the starting base for project assets, with depreciation accelerated over 5 years when book value, excluding mining rights, is used; or effective life (up to 25 years) when market value at 1 May 2010, including mining rights, is used. All post 1 May 2010 capital expenditure will be added to the starting base.”

In the case where the mining company opts to use a market value approach I take it to mean the depreciation takes place before the MRRT is calculated. This means the formula is:

MRRT = 30% x (75% x Earnings – Price(2010)/25)

Currently the mining industry average for P/E (price to earnings ratio) is 14, though in the case of BHP-Billiton it is 19. For an average miner then Price(2010)/25 = Earnings x 14/25 = 56% Earnings so the actual MRRT is based on 19% of Earnings. However the Price is fixed at the May 1 2010 value so this will not increase over time even though earnings will. Should earnings continue to rise at the dramatic rate we have seen in the past decade then the MRRT will eventually look more like the 22.5% base rate.

It appears that the Govt and the mining industry’s compromise is to push the revenue from the tax windfall out from today to later years. In a sense the mining industry has also removed the contentious “retrospectivity” of the tax by using the current high price and choice of 25 years depreciation to ensure the current value of the MRRT is minimised but will rise at 22.5% of increased earnings going forward.

Thanks to an observant reader who pointed out my error. Mea culpa.