Wednesday, November 19, 2014

The worst law in London

What does absurd government monomania in the face technological irrelevance look like?

Back in the early years of the 20th century, before computers had become widespread, the word 'calculator' actually referred to people. They would perform large numbers of arithmetic calculations, essentially being a slow and kludgy version of a spreadsheet.

Let's suppose, hypothetically, that being a human computer was a licensed and highly regulated profession in 1920. The government required you to study for years, and prove that you could do hundreds of long division calculations without making a mistake. A whole mystique grew up about 'doing the sums', the examination required to become a calculator. Only licensed calculators were permitted to perform arithmetic operations for more than half an hour a day in a commercial setting

Then IBM popularises the computer, and  Richard Mattessich invents the spreadsheet, and it becomes totally clear to absolutely everybody that 'doing the sums' is completely worthless as a skill set. Not only is keeping the current regulation raising costs by a lot, but it's producing huge deadweight loss from all the people devoting years of their life to studying something that's now completely redundant.

What do you think the response of the government and the public would be once it became apparent that the new technology was cheap and easily available? Immediate repeal of the absurd current regime? Outcry and anger at the horrendous government-mandated inefficiency?

Ha! Not likely,

I suspect the old regime would trundle merrily along, and the New York Times would write philosophically-minded pieces extolling the virtues of it.

Because, dear reader, there actually exists regulation exactly this disgraceful - The Knowledge, the required examination for London taxi drivers.

The New York Times Magazine wrote a long piece describing just how much taxi drivers are required to memorise:
"You will need to know: all the streets; housing estates; parks and open spaces; government offices and departments; financial and commercial centres; diplomatic premises; town halls; registry offices; hospitals; places of worship; sports stadiums and leisure centres; airline offices; stations; hotels; clubs; theatres; cinemas; museums; art galleries; schools; colleges and universities; police stations and headquarters buildings; civil, criminal and coroner’s courts; prisons; and places of interest to tourists.
 Test-takers have been asked to name the whereabouts of flower stands, of laundromats, of commemorative plaques. One taxi driver told me that he was asked the location of a statue, just a foot tall, depicting two mice sharing a piece of cheese. It’s on the facade of a building in Philpot Lane, on the corner of Eastcheap, not far from London Bridge.
What, in the name of all that is holy, is the purpose of making it a legal requirement of driving a taxi that you can name the location of a foot-tall statue of two mice that exists somewhere in London?

In the first place, the demand for finding the location of a statue like this from your taxi driver is zero. A precisely estimated zero, as the statisticians say. The revenues side of the ledger is a donut. It is literally inconceivable that the location of this statue has been the subject of a legitimate question towards a London taxi driver in the history of the entire profession. The only benefit is rent-seeking and limiting the size of the taxi industry. So why not just make them memorise the Roman Emperors in chronological order, or the full text of War and Peace? It would serve just as much purpose.

Not only is there no value to your taxi driver knowing this, but if I type in 'statue of two mice in London' into Google, the first image lists the location as 'Philpot Lane'. (The only sites that come up, ironically, are ones referencing the damn test, suggesting just how pointless this knowledge is). The internet has made memorising this kind of trivia, for all possible sets of London trivia, irredeemably useless.

Everything a taxi driver needs to know has been replaced by a smartphone. Everything. Which is why every man and his dog can drive Uber around just fine.

So what threadbare arguments does the NYT offer when, three quarters of the way through the article, it finally gets around to discussing the question of whether this damn test is worth anything?
Taxi drivers counter such claims by pointing out that black cabs have triumphed in staged races against cars using GPS, or as the British call it, Sat-Nav. Cabbies contend that in dense and dynamic urban terrain like London’s, the brain of a cabby is a superior navigation tool — that Sat-Nav doesn’t know about the construction that has sprung up on Regent Street, and that a driver who is hailed in heavily-trafficked Piccadilly Circus doesn’t have time to enter an address and wait for his dashboard-mounted robot to tell him where to steer his car.
Okay, I'll bite. They beat them in staged races by... how much? One minute? Maybe two? Perhaps 60 or 70% of the time? And the value of this time-saving is what, exactly? How does it compare to the extra time the person waited trying to hail a cab because of the artificial limit on the number of taxis?

It seems that New York Times writers are not required to distinguish between statements like 'the revenue side of the income statement here has literally no items on it' and the statement 'this is a positive NPV project that should be invested in'. Disproving the first statement is sufficient to establish the truth of the second. Look, there's a benefit! Really! See, it shows it must be a good idea to do the project.

Perhaps sensing the unpersuasive ring of this argument to anyone who's ever ridden in an Uber and found it cost 40% of the price, we then get another tack:
Ultimately, the case to make for the Knowledge may not be practical-economic (the Knowledge works better than Sat-Nav), or moral-political (the little man must be protected against rapacious global capitalism), but philosophical, spiritual, sentimental: The Knowledge should be maintained because it is good for London’s soul, and for the souls of Londoners. 
Well, in that case!

But riddle me this - how, exactly, can I tell whether this egregious rent-seeking and artificial deadweight loss monopoly is good for London's soul? 
The Knowledge stands for, well, knowledge — for the Enlightenment ideal of encyclopedic learning, for the humanist notion that diligent intellectual endeavor is ennobling, an end in itself. 
'Enlightenment'. You keep using that word, I do not think it means what you think it means.

Learning is definitely good. Government-mandated learning, especially when used as part of banning the consensual commercial activity of many individuals, is a wholly separate matter.

Just ask someone from the Enlightenment, like John Stuart Mill:
But, without dwelling upon supposititious cases, there are, in our own day, gross usurpations upon the liberty of private life actually practised, and still greater ones threatened with some expectation of success, and opinions propounded which assert an unlimited right in the public not only to prohibit by law everything which it thinks wrong, but in order to get at what it thinks wrong, to prohibit any number of things which it admits to be innocent.
Like, for instance, driving a cab without studying for years to satisfy a ludicrous exam requirement. 

But it's not just the higher taxi fees and difficulty getting a cab at the wrong time of night that make up the real tragedy here. What's the human toll of making every potential taxi driver learn this kind of nonsense, regardless of whether they ultimately succeed?
McCabe had spent the last three years of his life thinking about London’s roads and landmarks, and how to navigate between them. In the process, he had logged more than 50,000 miles on motorbike and on foot, the equivalent of two circumnavigations of the Earth, nearly all within inner London’s dozen boroughs and the City of London financial district. 
 It was now 37 months since he’d paid the £525 enrollment fee to sign on for the test and appearances. “The closer you get, the wearier you are, and the worse you want it,” McCabe said. “You’re carrying all this baggage. Your stress. Worrying about your savings.” McCabe said that he’d spent in excess of £200,000 on the Knowledge, if you factored in his loss of earnings from not working. “I want to be out working again before my kids are at the age where someone will ask: ‘What does your daddy do?’ Right now, they know me as Daddy who drives a motorbike and is always looking at a map. They don’t know me from my past, when I had a business and guys working for me. You want your life back.”
Apparently this must be a strong case of the false consensus effect, because reading this paragraph filled me with furious rage, but the NYT writes about it as one of those quaint things they do in old Blighty.

In the end, McCabe gets his license, so it's all a happy story!

He does not, however, get the three years of his life and £200,000 back.

How on earth do the parasites who run the testing and administration of this abomination justify all this to themselves? How do they explain their role in this shameful waste of money and fleeting human years, the restrictions on free and informed commerce, the ongoing fleecing of consumers, and the massive, groaning, hulking, deadweight loss of this monstrous crime against economic sense and liberty?

They must be either extraordinarily intellectually incurious, morally bankrupt, or both.

As the Russians are fond of saying, how can you not be ashamed?

Friday, November 7, 2014

They're all IQ tests, you just didn't know it

Here's one to file under the category of 'things that may have been obvious to most well-adjusted people, but were at least a little bit surprising to me'.

Many people do not react particularly positively when you tell them what their IQ is, particularly when this information is unsolicited.

Not in the sense of 'I think you're an idiot', or 'you seem very clever'. Broad statements about intelligence, even uncomplimentary ones, are fairly easy to laugh off. If you think someone's a fool, that's just, like, your opinion, man.

What's harder to laugh off is when you put an actual number to their IQ.

Having done this a couple of times now, the first thing you realise is that people are usually surprised that you can do this at all. IQ is viewed as something mysterious, requiring an arcane set of particular tasks like pattern spotting in specially designed pictures, which only trained professionals can ascertain.

The reality is far simpler. Here's the basic cookbook:

1. Take a person's score on any sufficiently cognitively loaded task = X

2. Convert their score to normalised score in the population (i.e. calculate how many standard deviations above or below the mean they are, turning their score into a standard normal distribution). Subtract off the mean score on the test, and divide by the standard deviation of scores on the test. Y = [ X - E(X) ] / [ σ(X)]

3. Convert the standard normal to an IQ score by multiplying the standard normal by 15 and adding 100:
IQ = 100 + 15*Y

That's it.

Because that's all IQ really is - a normal distribution of intelligence with a mean of 100 and a standard deviation of 15.

Okay, but how do you find out a person's score on a large-sample, sufficiently cognitively-loaded task?

Simple - ask them 'what did you get on the SAT?'. Most people will pretty happily tell you this, too.

The SAT pretty much fits all the criteria. It's cognitively demanding, participants were definitely trying their best, and we have tons of data on it. Distributional information is easy to come by - here, for instance. 

You can take their score and convert it to a standard normal as above - for the composite score, the mean is 1497 and the standard deviation is 322. Alternatively you can use the percentile information they give you in the link above and convert that to a standard normal using the NORM.INV function in excel. At least for the people I looked at, the answers only differed by a few IQ points anyway. On the one hand, this takes into account the possibly fat-tailed nature of the distribution, which is good. On the other hand, you're only getting percentiles rounded to a whole number of percent, which is lame. So it's probably a wash.

And from there, you know someone's IQ.

Not only that, but this procedure can be used to answer a number of the classic objections to this kind of thing.

Q1: But I didn't study for it! If I studied, I'm sure I'd have done way better.

A1: Good point. Fortunately, we can estimate how big this effect might be. Researchers have formed estimates of how much test preparation boosts SAT scores after controlling for selection effects. For instance:
When researchers have estimated the effect of commercial test preparation programs on the SAT while taking the above factors into account, the effect of commercial test preparation has appeared relatively small. A comprehensive 1999 study by Don Powers and Don Rock published in the Journal of Educational Measurement estimated a coaching effect on the math section somewhere between 13 and 18 points, and an effect on the verbal section between 6 and 12 points. Powers and Rock concluded that the combined effect of coaching on the SAT I is between 21 and 34 points. Similarly, extensive metanalyses conducted by Betsy Jane Becker in 1990 and by Nan Laird in 1983 found that the typical effect of commercial preparatory courses on the SAT was in the range of 9-25 points on the verbal section, and 15-25 points on the math section. 
So you can optimistically add 50 points onto your score and recalculate. I suspect it will make less difference than you think. If you want a back of the envelope calculation, 50 points is 50/322 = 0.16 standard deviations, or 2.3 IQ points.

Q2: Not everyone in the population takes the SAT, as it's mainly college-bound students, who are considerably smarter than the rest of the population. Your calculations don't take this into account, because they're percentile ranks of SAT takers, not the general population. Surely this fact alone makes me much smarter, right?

A2: Well, sort of. If you're smart enough to think of this objection, paradoxically it probably doesn't make much difference in your case - it has more of an effect for people at the lower IQ end of the scale. The bigger point though, is that this bias is fairly easy to roughly quantify. According to the BLS, 65.9% of high school graduates went on to college. To make things simple, let's add a few assumptions (feel free to complicate them later, I doubt it will change things very much). First, let's assume that everyone who went on to college took the SAT. Second, let's assume that there's a rank ordering of intelligence between college and non-college - the non-SAT cohort is assumed to be uniformly dumber than the SAT cohort, so the dumbest SAT test taker is one place ahead of the smartest non-SAT taker.

So let's say that I'm in the 95th percentile of the SAT distribution. We can use the above fact to work out my percentile in the total population, given I'm assumed to have beaten 100% of the non-SAT population and 95% of the SAT population
Pctile (true) = 0.341 + 0.95*0.659 = 0.967

And from there, we convert to standard normals and IQ. In this example, the 95th percentile is 1.645 standard deviations above the mean, giving an IQ of 125. The 96.7th percentile is 1.839 standard deviations above the mean, or an IQ of 128. A surprisingly small effect, no?

For someone who scored in the 40th percentile of the SAT, however, it moves them from 96 to 104. So still not huge. But the further you go down, the bigger it becomes. Effectively you're taking a weighted average of 100% and whatever your current percentile is, and that makes less difference when your current one is already close to 100.

Of course, the reality is that if someone is offering these objections after you've told them their IQ, chances are they're not really interested in finding out an unbiased estimate of their intelligence, they just want to feel smarter than the number you told them. Perhaps it's better to not offer the ripostes I describe.

Scratch that, perhaps it's better to not offer any unsolicited IQ estimates at all. 

Scratch that, it's almost assuredly better to not offer them. 

But it can be fun if you've judged your audience well and you, like me, occasionally enjoy poking people you know well, particularly if you're confident the person is smart enough that the number won't sound too insulting.

Of course, readers of this august periodical will be both a) entirely comfortable with seeing reality as it is, and thus would nearly all be pleased to get an unbiased estimate of their IQ, and b) are all whip-smart anyway, so the news could only be good regardless.

If that's not the case... well, let's just say that we can paraphrase Eliezer Yudkowsky's advice to 'shut up and multiply', in this context instead as rather 'multiply, but shut up about it'.

The strange thing is that even though people clearly are uncomfortable having their IQ thrown around, they're quite willing to tell you their SAT score, because everybody knows it's just a meaningless test that doesn't measure anything. Until you point out what you can measure with it. 

I strongly suspect that if SAT scores were given as IQ points, people would demand that the whole thing be scrapped. On the other hand, the people liable to get furious were probably not that intelligent anyway, adding further weight to the idea that there might be something to all this after all.

Sunday, November 2, 2014

On Being Sensible

There comes a point in one’s life where one surrenders to the lure of the practical, rather than the romantic. Bit by bit, the arguments for whimsical and aesthetic considerations make way for the fact that it is generally better to simply have one’s affairs in order. I suppose this is part of what maturity means – the extension of one’s planning horizon, so that the present value of sensible choices outweigh the desire to do things merely for the je ne sais quois of seeing something new.

For those of us of a mostly sensible bent, the appeal of solid, practical decisions doesn’t need much extra boosting. But even among such as I, there is still romance, in the broad sense. It just shows up in unexpected places.

While I don’t know exactly when this shift towards sensibility occurred (or even if it had a particular turning point), I do know one of the marks of its arrival.

The clearest indicator, at least to me, is the choice of which seat to choose on the aeroplane.

At some point, the desire to be able to easily get to and from the bathroom becomes the thing one values in this microcosm of life’s choices. Stepping over people is a pain, not being able to pee when one wants to is a pain, waking up people who fell asleep at inopportune times is definitely a pain, especially for the introverted. Life is just easier when you don’t have to worry about these things.

And yet, sometimes an overbooked flight forces you into a window seat, and you remember when you used to pick the window to watch the world beneath. You gaze out into the silvery moonlight, with wisps of clouds floating below you. Tiny patches of criss-crossing light mark the small towns far distant, defying the sea of darkness. The steady glow appear as lichen, growing in odd patterns along the grooves of a rock in an otherwise barren desert.

How many generations of your ancestors lived and died without seeing a sight so glorious?

How many would trade this for slightly more convenient bathroom access?

It is worth noting that this tradeoff does not need to be explained to small children. They instinctively get what’s amazing about watching the world below at takeoff and landing.

Particularly for those of us whose affairs are mostly in order, it is worth being occasionally reminded of the lesson.