Occasional reflections on Life, the World, and Mathematics

Archive for January, 2014

Of hockey sticks and statistics

[Updated at bottom] I recently read two books on climate science — or rather, two books on the controversies around climate science. One book was Michael Mann’s book The Hockey Stick and the Climate Wars; the other The Hockey Stick Illusion by Andrew Montford.

Now, I am, by inclination and tribal allegiance, of the party of Michael Mann, one of the world’s leading climate scientists. He and his colleagues have been subject to beastly treatment by political opponents, some of which is detailed in his book. And I only picked up the Montford book out of a sense of obligation to see what the opposing side was saying. And yet…

Montford’s book makes a pretty persuasive case. Not that climate science is bunk, or a conspiracy, or that anthropogenic global warming is a fiction — there is far too much converging evidence from different fields to plausibly make that claim (and indeed, Montford never makes such a claim) — but that a combination of egotism and back-scratching has seriously slowed down the process of evaluation and correction of sometimes sloppy statistical procedures, and tarnished the reputation of the scientific community generally.

I admit to a certain bias here: The attacks on Mann’s work that Montford describes are statistical in nature, and Mann’s response reminds me of the tone that is all too common when statisticians raise questions about published scientific work. Montford has a remarkable amount of technical detail — so much that I found myself wondering who his intended audience is — and the critiques he describes (mainly due to the Canadian mining engineer Steve McIntyre) seem eminently sensible. In the end, I don’t think they panned out, put they were genuine shortcomings in the early work, and McIntyre seems to have done the right things in demonstrating the failure of a statistical method, at least in principle, and to have earned for his trouble only incomprehension and abuse from Mann and his colleagues.

(more…)

The domestic elephant

I’ve long been bemused by the function of the elephant in the popular phrase “the elephant in the living room”. When it was invented by the recovery movement — I think in the 1980’s — it clearly was supposed to be both a shocking and ridiculous image. Families, it was saying, often deal with huge and obvious problems, such as addiction or abuse, by developing elaborate mechanisms for ignoring the very existence of the problem, that to an outsider seem both confounding and absurd. It’s as though you had an elephant in your living room, but acted as though you could pretend it wasn’t there.

The weird thing about the later career of the expression is that it has come to be an everyday expression — “That’s the elephant in the living room, isn’t it?” — as though it were perfectly ordinary to have such a thing; indeed, as though every living room has its elephants. I thought of this when I encountered an early use of elephants in the domestic setting, but with a different thrust. In Dominic Sandbrook’s history of Britain in the late 1970’s, Seasons in the Sun, there is a quote from Labour’s Welsh Secretary John Morris, acknowledging defeat in the devolution referendum:

If you see an elephant on your doorstep, you know what it is.

(The second episode of the new season of the BBC’s Sherlock made excellent comic use of the phrase, playing on its strange ubiquity. Giving a wedding toast to Watson, Sherlock reels off a list of some of their cases, concluding with “And then there’s the elephant in the living room.” For a moment it sounds like he’s switching modes, from the CV to something more personal, but then we have a split-second flashback to the detective encountering a real elephant in a real living room, and you remember that “The Elephant in the Living Room” does sound kind of like the title of a Conan Doyle story.)

“Institutions of Higher Perspiration”

“They don’t want to turn the universities into sweatshops. They’ll be institutions of higher perspiration.”

That was my conclusion about the trajectory to which our managerial overlords aspire, as I was trying to convince a colleague that he should support the UCU, the British academics union, and its escalating strike action. I walked the picket lines for the first time on Thursday, during our two-hour strike. There were about 20 of us there, and only a few were senior academics, which is somewhat disheartening. There were almost as many reporters as strikers, so I got to talk to    all of them. Their questions were interesting:

  1. Why do you think you deserve more pay, in this time of wage restraint? Other workers aren’t getting raises. I think they should join unions and demand higher wages too. It’s not a law of nature that we have “wage restraint” for everyone but the CEOs and fat-cat bankers. It’s a reflection of political decisions and power imbalance, and the effect of words like “time of wage restraint”. (more…)

Demographic fallacies and classical music

I was just reading an article in Slate with the title “Classical Music in America is Dead”. The argument boils down to two points:

  1. Classical music listeners are a small portion of the population.
  2. Relatively few young people in the audience.

With regard to (1), I thought it interesting that he writes

Just 2.8 percent of albums sold in 2013 were categorized as classical. By comparison, rock took 35 percent; R&B 18 percent; soundtracks 4 percent. Only jazz, at 2.3 percent, is more incidental to the business of American music.

What’s interesting is that, while jazz is certainly a minority taste, and its trajectory in American culture has closely paralleled that of classical music in the 20th century, I don’t think anyone would claim that jazz is dead.

He quotes the critic Richard Sandow, who makes a demographic argument that

And the aging audience is also a shrinking one. The NEA, ever since 1982, has reported a smaller and smaller percentage of American adults going to classical music performances. And, as time goes on, those who do go are increasingly concentrated in the older age groups (so that by now, the only group going as often as it did in the past are those over 65).

Which means that the audience is most definitely shrinking. Younger people aren’t coming into it. In the 1980s, the NEA reported, the percentage of people under 30 in the classical music audience fell in half. And older people also aren’t coming into the classical audience. If they were, we’d see a steady percentage of people in their 40s and 50s going to classical events, but we don’t. That percentage is falling.

Of course, this is vastly overstated. “Younger people” are “coming into it”… in smaller numbers than before. It’s an absurd fallacy (not uncommon, and addressed first (to my knowledge) in theoretical ageing research by Yashin et al. in the 1980s) that you can determine the longitudinal dynamics for individuals by looking at the cross-sectional age distribution.

Consider a model where individuals are recruited into classical music at a constant rate over their lifetimes, ending with 10% of the 80-year-olds. (We’ll leave the older population out of it.) Then about 11% of the adult audience would be under 30. Suppose there were now a change, just so that children under 15 were no longer being recruited into classical music, but after that age they continued to be enter at the same rate as before. Then the fraction of the adult audience under 30 would be halved, to about 5.5%. The number of people in their 40s and 50s going to concerts would decline by about 15%.

I’m not arguing that this is what is going on. A lot of the story is probably the general splintering of the music audience, and the fact that people increasingly prefer to stay home for their entertainment. (This is one reason why I have argued that the classical music establishment’s reliance on enormously expensive orchestras and opera companies is a mistake.) Just that you can’t make inferences about individual trajectories over time without data about individual trajectories.

A plan to completely segregate British schools

It’s hard to believe this is not a cynical ploy:

The wealthiest parents should have to pay the same fees to send their children to a top state school as they would to an independent school, a leading headteacher has proposed.

Independent schools should also offer a quarter of their places to children from the poorest of backgrounds, according to Anthony Seldon, the master at Wellington College.

In a report published by the Social Market Foundation (SMF), Seldon calls for a radical wave of reforms to end the divide between state and independent schools, enhance social mobility and offer young people a more rounded education.

Maybe he’s just trying to “bring new money into the state system, as well as incentivise state schools to perform better”, as he says, while being too naive to understand the consequences. Seems unlikely. He also says his plans would “reduce the domination of places at the top state schools by the children of well-off parents”. Indeed it would, since children of well-off parents would be almost completely absent from state schools.

If you think the well-off aren’t paying enough for education, why not just raise their income taxes? Why specifically penalise them for sending their children to state schools? There is already a prejudice — often unfounded — that private schools provide superior education. Forcing out the upper classes — and that’s clearly what would happen, if they were to be charged the same fees for a school that is less exclusive, and thus apparently inferior. The only ones who would benefit would be the independent schools, which would no longer need to compete with the state sector on price. How convenient!

If you want to know what the benefits really are of British independent schools, a colleague made it clear to me a while back, when he said he sends his children to private school so that they learn “self confidence”. I was reminded of this recently when someone spoke to me about having heard about research about “perceived fair wages”. “Someone who’s earning £30,000 a year isn’t going to apply for a job with a £60,000 salary. He knows it’s out of his league, that he doesn’t have the skills for that.” Now, I’ve encountered this notion of “perceived fair wages” in the  analysis of wage inequality: in particular, that women often are paid less because they are conditioned to expect lower wages. (For example here.) But this fellow thought it was simply a matter of everyone having a good sense of their proper place.

So how do you get to be a self confident banker who refuses to roll over and let The Man cut his multi-million pound bonus? Presumably, that’s the job of the independent schools.

Spying on allies

Reading about President Obama’s speech on the significant but minimal changes he is planning to make to US intelligence gathering in the wake of (but in no way as a consequence of, it goes without saying) the Snowden revelations, I found myself wondering: How much shit are US allies expected to take? I don’t mean their leaders (who have been promised a personal exemption from espionage). I mean the average people, who have put legal regimes in place that prevent their own governments from spying on them. Why should they be more accepting of spying by the US?

And it’s not as though there’s nothing they can do about it. The solution would be to limit the role of American companies in the European market, particular with regard to sales of computer technology and collecting private information. As well as monitoring US embassies and diplomats more closely for engagement in illegal espionage. The US is assuming they won’t dare, because of the economic power of the US, the goverments’ reliance on US military and diplomatic power. That’s probably true, in the short term, but it’s clearly going to be an expensive, ongoing drain on US influence.

And then there’s the recent full court press by US legislators on the various intelligence committees to assert that Edward Snowden is a foreign agent — a pretty egregious assertion to be making publicly, since it would potentially make him liable to the death penalty. For example, here’s Michael McCaul, chairman of the House committee on homeland security:

Hey, listen, I don’t think … Mr Snowden woke up one day and had the wherewithal to do this all by himself. I think he was helped by others. Again, I can’t give a definitive statement on that … but I’ve been given all the evidence, I know Mike Rogers has access to, you know, that I’ve seen that I don’t think he was acting alone.

What’s most interesting is that, for all the bluster about “evidence”, it sounds like the claim he’s making is, the NSA couldn’t possibly be so incompetent that some random guy could just come in and walk off with their complete files. Since Snowden is obviously not a master criminal, it can only be that he was being steered by brilliant, nefarious foreign intelligence services.

It’s not hard to guess who put the idea in his head that the NSA couldn’t possibly be so incompetent…

Hippie science

There are two books I’ve read sort of recently, From Counterculture to Cyberculture by Fred Turner and How the Hippies Saved Physics by David Kaiser, that supplement each other as a picture of how antimaterialistic culture of the SF Bay area in the late 1960s through mid-1970s produced a lot of nonsense, but also hugely important new impulses in hard technical fields. Silicon Valley grew out of an ethos of DIY back-to-the-earth-ism (hence the “Homebrew Computer Club”), while the Fundamental Fysiks Group at Lawrence Berkeley Lab, took the energy of enthusiasm for parapsychology and mysticism, and channeled it into revival of an inquisitive style of physics that rediscovered entanglement and Bell’s Theorem, and laid the groundwork for quantum cryptography and quantum information science.

Math and taxes

Oxford University has a new mathematics building. It’s very nice, looks like it would be a good place to work. But I found it fascinating to learn that the building is split in half, one part for teaching, one for research, with undergraduates basically forbidden to enter the research part. It’s a bit of a nuisance for the faculty, who need to give tutorials, and would sometimes find it convenient to do it in their Maths Institute office rather than in their college. Why is it? The story — I can’t vouch for its truth, but I’ve heard this from several people — is that it is for tax reasons. Apparently, research is considered a charitable activity, while teaching is… I don’t know, commercial activity? By splitting the building this way, they were spared paying VAT (close to 20%) on the construction.

This suggests an updated version of an old Jewish joke:

(Student tries to enter the research side of the Maths Institute Building.)

Receptionist: Where do you think you’re going? You’re not allowed in there.

Student: I’m looking for my brother. He’s a graduate student here.

Receptionist: Why don’t you ring him?

Student: He’s probably in one of the interaction zones, which have been designed to facilitate informal discussion outside the framework of traditional office spaces.

Receptionist: You could ring his mobile.

Student: As you are probably aware, the lovely metal cladding on the interior walls has exactly the right dimensions to block all mobile telephone and computer wireless radio signals. (True, apparently.) Please, I just need to go in for two minutes.

Receptionist: Well, okay. But don’t let me catch you learning in there!

What is income?

A strange paradox has opened up in the magnificently cruel US healthcare system. The Affordable Care Act was supposed to subsidise people with modest incomes (above the federal poverty line) to purchase private health insurance. Those below the poverty line — in fact, 138% of the poverty line — were supposed to be moved onto free health insurance with Medicaid. But Medicaid is administered by the states, and quite unexpectedly many states with Republican governors have refused the Medicaid expansion, out of pure political spite, making a hash of this system: Now individuals in those states whose income is below the federal poverty line still don’t get Medicaid (unless they qualify for Medicaid under the old rules, which are much more restrictive), but they can’t get the health care subsidies because they don’t earn enough.

Ignoring the huge human suffering that is being intentionally inflicted, I find this situation fascinating, because it’s something that shouldn’t exist in the world imagined by quantitative finance. How can you have too little income to receive public assistance? After all, this isn’t about net income. They don’t have to do anything with the money. It just needs to be recorded as income. Someone can give me a cheque for $1000, in payment for “personal services”, and I can give it back to pay his bill for “financial services”. There. I’ve just gotten another $1000 in income. You’d have to put some extra organisational effort in to make sure that you don’t incur any tax obligations.

But the point is, in the world of high finance, there isn’t a category of “income”. There’s just money. And they don’t leave money on the table just because there’s not enough in one particular accounting category. But the poor don’t just lack money; they don’t have people to structure their transactions in beneficial ways.

American exceptionalism: Harassing tourists and others

A discussion broke out on The Dish about the high-handed and sometimes abusive treatment that foreigners entering the US are subjected to, even citizens of international peers, like the EU, compared with the treatment that Americans (and others) receive entering most European countries. All foreigners entering the US are, by law, treated as “an intending immigrant” when they arrive, and need to prove otherwise. Now, a former immigration official has replied with a justification:

Congress demands by law that every applicant for a tourist visa (or any nonimmigrant visa) be considered “an intending immigrant” until they prove otherwise. With good reason – a lot of them are intending immigrants. Why is it Americans have such an easier time traveling to other countries than citizens of those countries have traveling here? Because Americans go home, that’s why.

Even when US citizens work off the books for a year or two overseas, they almost always wind up coming home. The same can’t be said of most foreigners who come here, even Europeans.

Sounds pretty convincing. But is it true? How would he know? I’m always suspicious of categorical claims like this, even when I make them myself.

How about if we compare the number of people from different countries living abroad. According to the French government, there are 1.6 million French citizens living abroad, so about 2.7% of the population. About 2 million Germans (not counting the 600,000 or so Russians who are officially considered “Germans” by ancient descent), so about 2.5%. And Americans? According to the Bureau of Consular Affairs (part of the State Department) there are 7.6 million Americans living abroad. Divided into a population of 316 million, we get about 2.4%. Even if some of these estimates are off, it’s clearly not a qualitative difference.

Sorry, America, the world just isn’t as into you as you like to imagine.

Tag Cloud