Posts filed under Politics (194)

The Royal Statistical Society has just commissioned an opinion poll to look at beliefs about policy-relevant issues and how they relate to reality.  The first few results:

1. Teenage pregnancy: on average, we think teenage pregnancy is 25 times higher than official estimates: we think that 15% of girls under16 get pregnant each year, when official figures suggest it is around 0.6%.
2. Crime: 58% do not believe that crime is falling, when the Crime Survey for England and Wales shows that incidents of crime were 19% lower in 2012 than in 2006/07 and 53% lower than in 1995. 51% think violent crime is rising, when it has fallen from almost 2.5 million incidents in 2006/07 to under 2 million in 2012.
3. Job-seekers allowance: 29% of people think we spend more on JSA than pensions, when in fact we spend 15 times more on pensions (£4.9bn vs £74.2bn).
4. Benefit fraud: people estimate that 34 times more benefit money is claimed fraudulently than official estimates: the public think that £24 out of every £100 spent on benefits is claimed fraudulently, compared with official estimates of £0.70 per £100.

You might look up what the actual figures are in New Zealand. To get you started, Paula Bennett claimed about $200 million in benefit fraud in 2010/11 (and about 10% of that was prosecuted) from about $9 billion, or about 22c per $100.

From the inimitable Dan Davies, a post on how often you’d expect all the front-page photos in major UK newspapers to be of white people

So a while ago on Twitter, I saw this storify by @KateDaddie, talking about ethnic minority representation in the British media, in the context of this article by Joseph Harker in the British Journalism Review. As I am a notorious stats pedant and practically compulsive mansplainer, my initial reaction was to fire up the Pedantoscope and start nitpicking. On the face of it, it is not difficult to think up Devastating Critiques[1] of the idea of counting “#AllWhiteFrontPages” as an indicator of more or less anything. But if I’ve learned one thing from a working life dealing with numbers (and from reading all those Nassim Taleb and Anthony Stafford Beer books), it’s that the central limit theorem will not be denied, and that simple, robust metrics with a broad-brush correlation to the thing you’re trying to measure are usually better management tools than fragile customised metrics which look like they might in principle be better.

Some folks at the MIT Media Lab have put together a simple web app that takes your Gmail headers and builds a social network.

Once you log in, Immersion will use only the From, To, Cc and Timestamp fields of the emails in the account you are signing in with. It will not access the subject or the body content of any of your emails.

Here’s mine, from my University of Washington email (with the names blurred, not that communicating with me is all that incriminating)

Obviously my email headers reveal who I email, and, unsurprisingly, the little outlying clusters are small groups or individuals involved in specific projects.  More interesting is how the main clump breaks down:  the blue and pink circles are statisticians, the red are epidemiology and genomics people that I have worked with in person in Seattle, and the green are epidemiology and genomics people that I work with only via email.

More on the ongoing fluoridation story:

Firstly, there is a very good statement from the PM’s chief science adviser, Peter Gluckman.  As he says, the scientific issues are entirely settled: at the concentrations used in treating water, fluoride reduces tooth decay and does not cause any harm.  At one time there was scientific uncertainty about adverse health effects; this is just not the case any more.  There is still a question of whether you want to treat the whole population in this way.  We add iodine to salt and folate to bread, but these prevent more serious illnesses than fluoridation does, and there are fewer people with an irrational fear of iodine or folate.

Second, the Herald has a Digipoll on fluoridation

The poll showed 48 per cent of New Zealanders supported the addition of fluoride – double the 25 per cent of those who opposed its use. A further 24 per cent believed the issue should be left to local councillors to decide.

Unfortunately, the poll tried to use a single question to address two unrelated issues: do you want fluoride in your water?, and should the decision be made nationally or locally?  As a consequence, it’s hard to interpret the results.  The ratio of for:against is about the same as in the Hamilton referendum that started fluoridation there in 2006, but if you assume all the people who want the issue decided locally  are really against fluoridation, the opinion would be nearly 50:50.  It obviously isn’t reasonable to assume everyone in favour of local decision-making is against fluoridation — I’m on record as a counterexample — but there’s no way to know how these folks would split.

The Herald story goes on to quote an antifluoride lobbyist

Ms Byrne said the group had science to back its claims that fluoride was toxic and harmful when added to water and without applying it directly to teeth offered none of the benefits health authorities claimed.

However, that is hotly disputed within the science community.

It’s not disputed within the scientific community, it’s disputed by the scientific community. The science, as Sir Peter observes, is settled.

In a Stat-of-the-Week nomination, Nick Iversen points out a Herald story about the convention centre deal, under the headline “Support disappears for convention deal”

Public opinion has turned against the Government’s SkyCity international convention centre deal just days before it is due to be signed off, allowing for 230 extra poker machines at the downtown Auckland casino.

The latest Herald-DigiPoll survey shows 61.5 per cent of those polled disapprove of the deal while 33.8 per cent approve.

That’s a sharp turnaround from a year ago when a similar poll found 40.3 per cent disapproved and 57.3 supported it.

As Nick and the SkyCity spokesperson point out, the poll last year had a ‘conditionally approve’ option, so they aren’t really comparable. In fact it’s worse than that. the Herald’s headline last year was “Public opposed to SkyCity deal — or want conditions“, so it’s not just a matter of interpreting last year’s data; the story isn’t even consistent with last year’s headline.

Last year, the poll found 40.3% disapproved, 37.7% approved if the total number of gaming machines across Auckland decreased, and 19.6% approved.   This year 61.5% disapprove and 33.8% approve. It’s hard to decide how the 37.7% of conditional approvals should be apportioned, since the number of machines is going down, but it’s going down for reasons basically unrelated to the SkyCity deal.

Some possibilities

• All the conditional approvals should be treated as approvals. That’s the Herald’s current interpretation and gives 57.3% approval last year, and a roughly 25% decrease in approval
• All the conditional approvals should be treated as disapprovals. That was the Herald’s interpretation last year, and gives 19.6% approval last year and and a roughly 13% increase in approval
• The conditional approvals should be ignored, and we should look at the proportion of approval among those approving or disapproving.  That gives 32.7% approval last year, almost identical to this year.

It’s clear that you really can’t say anything very useful about the change using the two different sets of questions.  On the other hand, it’s also clear that the majority in Auckland is currently opposed to the deal, and if public opinion was relevant to the decision-making process, that, rather than the change since last year, would be the important fact.

In the Herald, in late May, there was a commentary on the importance of freeing-up the GCSB to do more surveillance. Aaron Lim wrote

The recent bombings at the Boston Marathon are a vivid example of the fragmented nature of modern warfare, and changes to the GCSB legislation are a necessary safeguard against a similar incident in New Zealand.

 …

Ceding a measure of privacy to our intelligence agencies is a small price to pay for safe-guarding the country against a low-probability but high-impact domestic incident.

Unfortunately for him, it took only a couple of weeks for this to be proved wrong: in the US, vastly more information was being routinely collected, and it did nothing to prevent the Boston bombing.  Why not?  The NSA and FBI have huge resources and talented and dedicated staff, and have managed to hook into a vast array of internet sites. Why couldn’t they stop the Tsarnaevs, or the Undabomber, or other threats?

The statistical problem is that terrorism is very rare.  The IRD can catch tax evaders, because their accounts look like the accounts of many known tax evaders, and because even a moderate rate of detection will help deter evasion.  The banks can catch credit-card fraud, because the patterns of card use look like the patterns of card use in many known fraud cases, and because even a moderate rate of detection will help deter fraud.  Doctors can predict heart disease, because the patterns of risk factors and biochemical meausurements match those of many known heart attacks, and because even a moderate level of accuracy allows for useful gains in public health.

The NSA just doesn’t have that large a sample of terrorists to work with.  As the FBI pointed out after the Boston bombing, lots of people don’t like the United States, and there’s nothing illegal about that.  Very few of them end up attempting to kill lots of people, and it is so rare that there aren’t good patterns to match against.   It’s quite likely that the NSA can do some useful things with the information, but it clearly can’t stop `low-probability, high-impact domestic incidents’, because it doesn’t.  The GCSB is even more limited, because it’s unlikely to be able to convince major US internet firms to hand over data or the private keys needed to break https security.

Aaron Lim’s piece ended with the typical surveillance cliche

And if you have nothing to hide from the GCSB, then you have nothing to fear

Computer security expert Bruce Schneier has written about this one extensively, so I’ll just add that if you believe that, you can easily deduce Kristofferson’s Corollary

Freedom’s just another word for nothing left to lose.

The Herald, writing about Hamilton’s pending removal of fluoridation from their water supply

A Hamilton City Council tribunal examining the topic has re-ignited intense public debate on the issue, with 89 per cent of the 1,557 submissions made to it in favour of stopping fluoridation. In 2006, 70 per cent of residents who voted in a referendum backed fluoride.

This actually isn’t evidence or even a suggestion of a change in opinion. All we can tell from the numbers is that 1386 people now want fluoride removed.  Public submissions are useful qualitatively, not quantitatively.

It may be true that the people of Hamilton don’t want fluoride in their water, in which case I think they are unwise, but it’s their problem. Confusing self-selected numbers with referendum votes  isn’t going to help determine what they want, [and neither is the exclusion from voting of three of twelve council members on the grounds that they also sit on the DHB and so have thought about the issues before]

Andrew Dillnot has the dream job for a statistics blogger — he is responsible for telling British MPs and government departments that their misrepresentations of official statistics are naughty.  From a Guardian story

But the big number was – there is no other word for it – a lie. Dilnot, now responsible for protecting the integrity of official statistics, exposed it as a lie this week, albeit using mild Whitehall language in letters to Shapps and Iain Duncan Smith, the work and pensions secretary. The 878,300 alleged malingerers had never received incapacity benefit. They were new claimants, aggregated over three-and-a-half years. Many (probably most) withdrew their claim because they recovered from their condition or found a new job. In 2011-12, out of 603,600 established benefit claimants referred for the new medical tests, just 19,700 (3.3%) withdrew before taking them. That figure – which most of us would think small – represented the true scale of people pretending to be sick.

From BBC Radio: listen online

On Start the Week Emily Maitlis talks to the Executive Chairman of Google, Eric Schmidt about the digital future. A future where everyone is connected, but ideas of privacy, security and community are transformed. Former Wikileaks employee James Ball asks how free we are online. The curator Honor Harger looks to art to understand this new world of technology. And worried about this brave new world? David Spiegelhalter, offers a guide to personal risk and the numbers behind it.

(via @cjbayesian)

Keith Ng’s budget visualisation now has today’s newly-released Government budget.

(update) There’s also one at Stuff, by Harkanwal Singh (note that it uses nominal, not inflation-adjusted amounts)