Occasional reflections on Life, the World, and Mathematics

Archive for the ‘Academic’ Category

Statistics, politics, and causal theories

A new headline from the Trump era:

Fewer Immigrants Are Reporting Domestic Abuse. Police Blame Fear of Deportation.

Compare it to this headline from a few months ago:

Arrests along Mexico border drop sharply under Trump, new statistics show

This latter article goes on to comment

The figures show a sharp drop in apprehensions immediately after President Trump’s election win, possibly reflecting the deterrent effect of his rhetoric on would-be border crossers.

It must be noted that these two interpretations of declining enforcement are diametrically opposed: In the first case, declining reports to police are taken as evidence of nothing other than declining reports, whereas the latter analysis eschews such a naive interpretation, suggesting that the decline in apprehensions is actually evidence of a decline in the number of offenses (in this case, illegal border crossings).

I don’t mean to criticise the conventional wisdom, which seems to me eminently sensible. I just think it’s interesting how little the statistical “facts” are able to speak for themselves. The same facts could mean that the election of Trump was associated with a decline in domestic violence in immigrant communities, and also with a reduction in border patrol effectiveness. It’s hard to come up with a causal argument for either of these — Did immigrant men look at Trump with revulsion and decide, abusing women is for the gringos? Did ICE get so caught up with the fun of splitting up families in midwestern towns and harassing Spanish speakers in Montana, that they stopped paying attention to the southern border? — so we default to the opposite conclusion.

Do loony leftists use the right-hand rule?

So Leave.EU is still active, and apparently last year they were soliciting a graphic to ridicule journalist Carole Cadwalladr:

As a mathematical scientist it strikes me as significant that she is considered to be discredited by association with three images: Flat Earth, Illuminati (though it looks to me like the Masonic eye from the US dollar bill), and what looks like a cheat sheet for an introductory electromagnetism course. Down in the corner we see that she’s been learning the right-hand rule for multiplying vectors. Right above it she has the formula for calculating power, which seems problematic.

Neanderthal science

I just listened to all of a two-hour discussion between journalist Ezra Klein and professional atheist Sam Harris, about Harris’s defense of the right-wing policy entrepreneur (as Matthew Yglesias has described him) Charles Murray, famous for his racist application of intelligence research to public policy, most famously in a notorious chapter of his book The Bell Curve. Klein pushes back effectively against Harris’s self-serving martyrdom — Harris, not unreasonably, identifies with the suffering of a wealthy and famous purveyor of quack science whose livelihood is ever-so-slightly harmed by public criticism* — but he doesn’t sufficiently engage, I think, with Harris’s contention that he is promoting the values of real science. Unfortunately, the “mainstream social science” that Harris and Murray are promoting exists only in secret messages from “reputable scientists in my inbox, who have totally taken my side in this, but who are too afraid to say so publicly”. Harris doesn’t allow for a second that there is any good-faith argument on the other side. Anyone who disagrees is merely trying to shut down scientific progress, or simply confusing scientific truth with do-gooding wishful thinking.

The truth of the matter is, Murray and other brave seekers of truth are doing the opposite of helping to clarify reality. They are wading into a swamp of confusion, and pulling out some especially stinky slime that they can hurl at disfavoured groups.

As much as Harris tries to promote Murray as a pure-hearted “content-of-our-character” anti-racist individualist, as long as “race” exists as a social factor affecting people’s self-image, the communities they belong to, and the way they are perceived by others, it remains a potent social force. When demographers argue that “race” isn’t “real”, they are saying that racial categories don’t separate natural clusters by genetic or physical traits. When Murray says, let’s stop talking about race, let’s talk about individual genetic endowments, he is saying that racial groupings have no causal effect on their own, but only label clusters whose difference arise from deep physical causes — wrong on both sides. (more…)

Fannee Doolee likes college professors but she doesn’t like scientists

When I was a child, there was a regular feature on the program Zoom called “Fannee Doolees”: Riddles about the titular character who liked some things, but didn’t like other very similar things, interspersed with the question “Why do you think that is?”. Listeners could send in their own suggestions, to show they’d figured out the pattern, like: Fannee Doolee likes sweets, but she doesn’t like candy. Fannee Doolee likes batteries, but she doesn’t like electricity. The trick was, FD likes only words that have a double letter in them. So naturally I thought of this when I saw this plot (pointed out by Kevin Drum) from a paper on political partisanship by political scientist Larry Bartels, showing the results of a survey that asked for a favourability rating on a zero-to-ten scale for various groups and institutions, separated between self-identified Republicans and Democrats.

Screenshot 2018-03-20 21.59.44

Looking at this it really jumped out at me that Republicans have widely divergent views of “college professors” and “scientists”. Scientists are well up in the positive zone, about equal with Jews, and Republicans themselves, whereas college professors are well down into negative territory, next to gays and environmentalists. They also like wealthy people, but they don’t like Wall Street Bankers. Fannee Doolee is definitely not a Republican.

Weirdly, Republicans say they like men and women both more than they like Republicans.

Counting to 20

I’m sitting in the Sheldon Theatre for a meeting of Congregation, Oxford University’s governing body, to discuss a suspension of rules to allow a discussion of the proposed resolution to change the university’s negotiating posture on the pension issue. (The motion was proposed with only 18 days notice, rather than the required 22.) The rules allow 20 members to rise (ageism!) to object, which blocks consideration.

It surprised me how determined the university administration was to block this vote.

But it also surprised me how difficult it was to count to 20. It took around ten minutes. They seemed to keep getting confused, and needing to recount various sections.

Whether there really were 20 I’m not sure, but they finally said there were, and adjourned the meeting, to shots of “Shame!”

At which point the meeting was spontaneously moved outside, and a wildcat vote was held.

Natural frequencies and individual propensities

I’ve just been reading Gerd Gigerenzer’s book Reckoning with Risk, about risk communication, mainly a plaidoyer for the use of “natural frequencies” in place of probabilities: Statements in the form “In how many cases out of 100 similar cases of X would you expect Y to happen”. He cites one study forensic psychiatry experts who were presented with a case study, and asked to estimate the likelihood of the individual being violent in the next six months. Half the subjects were asked “What is the probability that this person will commit a violent act in the next six months?” The other half were asked “How many out of 100 women like this patient would commit a violent act in the next six months?” Looking at these questions, it was obvious to me that the latter question would elicit lower estimates. Which is indeed what happened: The average response to the first question was about 0.3; the average response to the second was about 20.

What surprised me was that Gigerenzer seemed perplexed by this consistent difference in one direction (though, obviously, not by the fact that the experts were confused by the probability statement). He suggested that those answering the first question were thinking about the same patient being released multiple times, which didn’t make much sense to me.

What I think is that the experts were thinking of the individual probability as a hidden fact, not a statistical statement. Asked to estimate this unknown probability it seems natural that they would be cautious: thinking it’s somewhere between 10 and 30 percent they would not want to underestimate this individual’s probability, and so would conservatively state the upper end. This is perfectly consistent with them thinking that, averaged over 100 cases they could confidently state that about 20 would commit a violent act.

Why I am striking

Strike actions have been conducted every year or two since I’ve been at Oxford. At the first one I participated unquestioningly. My previous job was at Queen’s University in Ontario, where everyone was a member of the union, and the union was our joint instrument for protecting our rights, both academic and contractual. So if there’s a strike, I figured, everyone stops working.

I felt like I’d fallen for a prank. There were three days of “strikes”, on three different weeks, I signed up to forego my salary for those days, joined three other people on a picket line for an hour, while all of my colleagues were at work — and all my work still had to get done on other days. The strikes would go unnoticed, but the 1.5% after-inflation salary cut would be replaced by 1%, approximately replacing the pay lost by striking, and the whole process would repeat a year or two later.

I consequently ignored the most recent strike action, to begin with. But I’ve now come to realise that this is a more serious matter. The strike isn’t continuous, but it covers most workdays over a period of four weeks (to begin with). The basis of the conflict is more fundamental than a one-percent salary cut: the decision by employers to offload pension risk onto the individuals, in replacing defined-benefit plans by defined-contribution plans. It’s not just a matter of how we — and particularly our younger colleagues — are being treated, and how it will affect people’s financial plans. It is part of a longer-term struggle about who will stay in the profession, and who will choose to enter the profession in the future. And of the struggle to define the nature of the academic profession, and of academic institutions.

I entered academia long after those halcyon days when there was an easy path for any reasonably smart person to a secure job. But there was still a sense that an academic career was a plausible aspiration for normal people from all kinds of backgrounds, and that one could plausibly trade away a quick grab at the high salaries of private industry against a quieter, socially useful, and more contemplative life, that would provide at least financial security and a long planning horizon.

Last week we received a letter from Oxford’s registrar, arguing that the pension cuts were unavoidable. Not to worry, though:

Nothing in the current proposals changes anything that USS members have already accrued as pension rights.

This line rankled. It is a direct appeal against solidarity. For all the aggravation that one should have over opaque employment practices and discriminatory pay at Oxford, the fact is that every one of us who have permanent jobs at a leading research university has won the lottery grand prize compared with what is left for equally talented students. We are clinging to the last helicopters fleeing the ruins of the academia that most of us aspired to join. The younger academics who had the poor foresight to be born too late are being overrun.

Decisions are being made on the basis of an ideological assertion that co-operative academic institutions motivated by a shared pursuit of truth and scientific advancement have no future: Universities need to emulate the soi-disant successes of British industry. They need to be ruthlessly hierarchical and constantly marketing their “product”. The proximate cause of  the strike is a qualitative cut in pension rights — the shift from defined benefits to defined contributions — driven by irrational changes to official pension valuation methodology, combined with universities’ boundless need for capital to fund expansion. (Lest one think that expansion might be good for higher education in the long run, and hence for higher education careers, it should be noted that student numbers have actually been declining. In keeping with its ideology of competition, the government seems to be promoting a contest for dwindling resources.) Those of us who got in ahead of the capitalist singularity are being promised a partial reprieve, in exchange for acquiescence to the

I don’t want to strike. It creates conflict. It disrupts the lives of students. It disrupts my own life. At a time when the position of all foreigners is particularly under threat in this country, I’d like to keep my head below the parapets. I don’t like getting caught up in fights between different groups of English people, that always seem to involve subtexts that no foreigner can understand. Especially in Oxford, participating in strike action feels like the opposite of collective action.

In discussions with several colleagues in recent days I tried to argue for why I, personally, shouldn’t strike. No one tried to persuade me otherwise, but I frankly could even persuade myself. The arguments rang hollow, particularly the argument that I don’t know which portion of my work counts for my three-days contribution to the university. (Oxford academics have a complicated division of roles between university and college, and the colleges are not being targeted by the strike. Oddly, because all reports suggest that they had an outsized role in provoking the strike.)

I am inspired by reports of young academics walking picket lines, and humbled by the support of the National Union of Students, which wrote

We believe that fairly rewarded staff are the cornerstone of the university experience and that the proposal by Universities UK to substantially cut the pensions of members of the USS pension scheme will be hugely damaging if implemented.

Day by day we accept the small privileges that accrue to us from the steady erosion of opportunities for the younger generation of teachers and scholars. Now, in the rare circumstance where a decision is forced upon us, where the cost to ourselves is minimal, where the students themselves — “think of the poor students!” — are collectively supporting the action, at the very least now we can take this tiny step in support of our colleagues, and of hope for better conditions in the future. A step that will take me out of my office and down the street, to the picket line.

Golfing VCs

Economist David Blanchflower wrote an article for The Guardian inviting us to pity the poor underpaid university vice chancellors with their paltry sub-million-pound salaries. In discussing what an awful job it is, and why you

A vice-chancellor’s schedule is set for them. The job has a huge effect on family life. There are few places to hide and find privacy. You are always on show, even on the golf course.

Even on the golf course! Have these vice-chancellor-oglers no shame?

Oddly enough, the analysis by this economist, which included the striking phrase “If you pay peanuts, you get monkeys” — the monkey here being everyone who is not a vice chancellor — omitted any evidence that universities do indeed prosper from having non-monkeys doing the job. I mean, there are all kinds of jobs that are hard and important, but there’s a limit to how much you’re willing to pay to get just a tiny bit of extra talent (assuming that you can even reliable recognise those distinctions in the course of the hiring process). The suggestion is that you need to pay huge sums just to get one of the exceptional rare individuals who is even minimally qualified not to run the university into the ground. “In the end, there are few qualified and willing applicants.” I’d like to see some working-out on that problem.

Why people hate statisticians

Andrew Dilnot, former head of the UK Statistics Authority and current warden (no really!) of Nuffield College, gave a talk here last week, at our annual event honouring Florence Nightingale qua statistician. The ostensible title was “Numbers and Public policy: Why statistics really matter”, but the title should have been “Why people hate statisticians”. This was one of the most extreme versions I’ve ever seen of a speaker shopping trite (mostly right-wing) political talking points by dressing them up in statistics to make the dubious assertions seem irrefutable, and to make the trivially obvious look ingenious.

I don’t have the slides from the talk, but video of a similar talk is available here. He spent quite a bit of his talk trying to debunk the Occupy Movement’s slogan that inequality has been increasing. The 90:10 ratio bounced along near 3 for a while, then rose to 4 during the 1980s (the Thatcher years… who knew?!), and hasn’t moved much since. Case closed. Oh, but wait, what about other measures of inequality, you may ask. And since you might ask, he had to set up some straw men to knock down. He showed the same pattern for five other measures of inequality. Case really closed.

Except that these five were all measuring the same thing, more or less. The argument people like Piketty have been making is not that the 90th percentile has been doing so much better than the 10th percentile, but that increases in wealth have been concentrated in ever smaller fractions of the population. None of the measures he looked was designed capture that process. The Gini coefficient, which looks like it measures the whole distribution, because it is a population average is actually extremely insensitive to extreme concentration at the high end. Suppose the top 1% has 20% of the income. Changes of distribution within the top 1% cannot shift the Gini coefficient by more than about 3% of its current value. He also showed the 95:5 ratio, and low-and-behold, that kept rising through the 90s, then stopped. All consistent with the main critique of rising income inequality.

Since he’s obviously not stupid, and obviously understands economics much better than I do, it’s hard to avoid thinking that this was all smoke and mirrors, intended to lull people to sleep about rising inequality, under the cover of technocratic expertise. It’s a well-known trick: Ignore the strongest criticism of your point of view, and give lots of details about weak arguments. Mathematical details are best. “Just do the math” is a nice slogan. Sometimes simple (or complex) calculations can really shed light on a problem that looks to be inextricably bound up with political interests and ideologies. But sometimes not. And sometimes you just have to accept that a political economic argument needs to be melded with statistical reasoning, and you have to be open about the entirety of the argument. (more…)

The World’s Greatest University(TM) has a bad PR day

Pity the poor flack in Harvard’s press office that needs to deal with two remarkable instances of cravenness in a single day: Harvard’s Kennedy School of Government bowed to criticism from the CIA to revoke its invitation to military whistleblower and transgender activist Chelsea Manning to come for a short stay as a “visiting fellow”. And Michelle Jones who rehabilitated herself in prison after a gruesome childhood that culminated in the neglect, abuse, and possibly murder of her own child, to emerge 20 years later as a noted historian of the local prison system, to be admitted to multiple graduate programmes in history, but had her acceptance at Harvard overruled by the university administration. (more…)

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