The grammar school fallacy

No fallacy dominates popular attitudes to education like post hoc ergo propter hoc (“after this, therefore because of this”). Y follows X, so X must have caused Y.

Consider three common lines of reasoning. Much of the British elite went to Oxford and Cambridge, therefore Oxford and Cambridge must be the best universities and ambitious youngsters should therefore strive to get into those institutions. University leavers tend to get higher paying jobs, therefore a university education must give young people the skills necessary to secure such employment, and therefore almost all young people should go to university.

And because grammar schools produce children with excellent exam results, that must be because grammar schools are excellent schools, and we should wish to see more of them. Post hoc ergo propter hoc.

But it ain’t necessarily so. What if the 18-year-olds who go to Oxford and Cambridge and other Russell Group universities are already bright? Perhaps those particular institutions aren’t really adding very much in academic terms at all.

What if university leavers already had many of the skills required to thrive in the modern workplace before they arrived? Perhaps a university education doesn’t actually confer those abilities after all, and that from an economic perspective, it’s a waste of resources to cram ever more young people through this particular form of higher education.

To identify whether a particular factor causes an outcome, we need to consider the counterfactual. In other words, to ask what would have happened in the absence of that factor? Establishing counterfactuals is tough but, to be credible, an analysis has to at least attempt it.

Now let’s consider the case of the 164 grammar schools in England, which select girls and boys at age 11 on the basis of their academic ability. There’s no question that the 167,000 students who attend them get better GCSE and A level results on average, relative to the roughly three million pupils who attend nonselective state schools. But is that because of the quality of the teaching at the schools themselves and their selective mechanisms? Or is it because of the pre-existing abilities of the children who attend them, perhaps because they come disproportionately from well-off families? What’s the counterfactual? Might those children perhaps have gone on to do well anyway in another school environment, such as a comprehensive? Research from Durham University suggests a definitive answer to that.

When the academics make statistical adjustments for the prior abilities of students and the wealth of their family background (grammar schools do tend to be dominated by the middle classes), they find little evidence that these schools add much.

However, there is some pretty compelling statistical evidence that poorer children in regions such as Kent, where grammar schools are still relatively common, have worse academic results than one would otherwise expect. This suggests brighter children with wealthier parents tend to drive up overall standards in comprehensive schools. But the corollary of this is that the presence of grammar schools is indirectly harmful to the wider local schools system. “Grammar schools in England endanger social cohesion for no clear improvement in overall results,” concludes Durham’s Professor Stephen Gorard.

When she became Prime Minister in 2016, Theresa May promised she would allow the establishment of new grammar schools. For the first time since the mass comprehensive conversions of the 1960s, the government planned to encourage them. The evaporation of her authority after last year’s election fiasco has forced May to retreat from that. Yet it remains Government policy to allow existing grammar schools to expand, in itself a significant departure from the cross-party policy consensus of the past 40 years.

Many of those who want to expand academic selection at age 11 (though not all) are inspired by decent motives. They not only look upon the good academic results produced by grammar schools and wish to proliferate that success, but also observe that the post-war era of expanding grammar schools was also an era of rising social mobility, when it felt like talented young people from modest backgrounds could “get on”.

Yet they may have been tripped up by another statistical fallacy: confusing correlation with causation. Was the acceleration of social mobility of this era due to the introduction of grammar schools in the 1944 Education Act? Or more “room at the top” in British economic life, as white-collar work and the professions expanded rapidly thanks to rapid technological change? The evidence leans to the latter.

The question of how to resurrect the social mobility of the post-war era is a complex one. But when it comes to education, the most statistically rigorous research we have (drawing on the research of economists, psychologists, neuroscientists and statisticians) strongly suggests the key to boosting lifetime attainment lies in improving (very) early years care and in targeting resources on the least advantaged.  If ministers really care about the life chances of the poorest, they should invest heavily here, reverse the post-2010 cuts to Sure Start funding, and, finally, shed those beguiling grammar school fallacies.

#correlationcausation #grammarschools #posthocergopropterhoc

The hidden fees "drip-off"

Donald Trump versus Simon Calder. There was only ever likely to be one winner.

Thanks to The Independent’s indefatigable travel correspondent the £ 20 “resort fee” that Trump’s Scottish golf course, Turnberry, had attempted to impose on its guests has been pretty swiftly removed by its managers.

Simon’s hand was doubtless strengthened by the fact that such concealed-but-compulsory charges for things like wi-fi, swimming pool access, in-room coffee machines etc are actually illegal here in the UK.

And long may it remain so. This is one kind of American import against which we should resist as vigorously as Trump himself seeks to repel Chinese steel and Mexican-made cars.

A report commissioned by the outgoing Obama administration in 2016 notes that such sneaky fees in the American hospitality industry extorted more than $2bn (£1.4bn) out of Americans in 2015. Despite only being introduced in the late 1990s such fees have metastasised and now make up almost a fifth of the revenues of US hotels.

But before we get self-congratulatory about our enlightened proscription of resort fees, we might remember that considerable tranches of our own markets are also, and apparently quite legally, distorted by what’s sometimes known as “drip pricing”. 

On my way to Darlington from London on Virgin’s East Coast mainline last week I logged on to the train’s “free” wi-fi to discover that it was only complimentary for those who had booked their ticket directly through Virgin’s website, something I suspect very few of their customers actually do. So to get online for a couple of hours I had to fork out £ 5.

There are plenty of other examples of sharp selling. Those who hire a car at a UK airport will still often find all manner of unexpected compulsory additions wrung out of them upon arrival, such as insurance and refuelling. And of course there are those notorious excess baggage charges from airlines.

The tricks can be subtle too. An entire industry exists to create “strategic choice architecture” to exploit our psychological frailties over pricing. Sales assistants are trained to “upsell”, flogging everything from pointless insurance for small household electronics to extra fries with your hamburger. 

And have you noticed how clothing retailers’ seasonal “sales” now actually tend to cover most of the year? And why are printers so cheap, yet the replacement cartridges so expensive? 

Is it something to worry about though? Doesn’t it all even out in the end, as we get wise to the scams and tricks over time? Doesn’t the free market work its magic? 

Possibly not. The White House report into drip pricing concluded that such charges aren’t just an irritation, but do wider economic damage by interfering with the price signals that free markets need to function efficiently.

If you think a room is on sale at $80 you might consider it decent value and book it. But if you’d known the real price was actually $110 you might not have. Or perhaps you might have booked a different hotel with an all-in fee of $90. Yet if that $90 hotel had needed to compete with the headline prices offered by a dishonest one, it too might have had to conceal it’s own true room price, adopting a spurious resort fee of its own. And so on and so on. It’s easy to see how a market can quite soon become corrupted.

The rise of price comparison websites seems to have accelerated this race to the bottom on tariff opacity in some markets. As we do an increasing amount of our shopping and purchases online, this problem will likely grow. When people are making a decision on a one-off purchase remotely, based on headline quoted price, they are inherently vulnerable to exploitation.

Vendors should put their houses in order and ensure genuine price transparency. If they will not – or cannot – more will be expected of regulators. And the longer the “drip-off” continues, the heavier the hand of that intervention is liable to be.

#DonaldTrump #drippricing #hiddenfees #SimonCalder

Trump’s pride in his lies makes him even much more dangerous than we thought

Donald Trump tells lies. That’s hardly news, of course. And certainly not fake news. According to The Washington Post, which is assiduously keeping count, the 45 US President has uttered or tweeted more than 2,000 false or misleading statements since swaggering into the White House. That’s an average of around five a day.

But does Trump spew this waterfall of lies knowingly? Or could it be that he is just chronically ignorant and obscenely intellectually lazy? Or is it perhaps a case of cognitive impairment, as suggested in a recent book? Is Trump mentally unable to distinguish between fantasy and reality? A leaked audio recording of Trump recalling his talks with the Canadian Prime Minister Justin Trudeau at a private fundraising event in Missouri gave us a pretty strong steer on this. Trump bragged to his audience that he asserted something to the Canadian leader that he simply didn’t know was true or not.

“I said, ‘Wrong, Justin, you do [have a trade surplus with the US].’ I didn’t even know … I had no idea. I just said, ‘You’re wrong.'” In other words, Trump has admitted that he lies knowingly and shamelessly. Indeed, the Missouri audio demonstrates that he’s not merely shameless, but proud of his untruths. There are problems with psychological diagnoses from a distance, but it’s worth noting that pathological lying and immunity to feelings of guilt are traits associated with psychopaths.

Is there anything more to be said about Trump’s estrangement from truthfulness? Yes. And it’s the fact that Trump is a political liar. The lies are not simply intended to deceive; they are, as the Russian dissident Masha Gessen has argued, a brute assertion of the primacy of power over truth. They indicate a conception of power that simply does not recognise the authority of truth.

Trump says something that is untrue, that people around him know is untrue, that he himself knows to be untrue, and which he knows they know is untrue. Why? As a statement of his authority and the absolute nature of it. As the Missouri audio also reveals, the job of his aides, when a lie is told by their master, is to locate some evidence that his assertions are, in fact, correct.

By forcing his spokespeople and subordinates to repeat, defend or rationalise his blatant falsehoods in public, he destroys their own reputations and their own sense of self-respect. This may, or may not, be intended as a means of binding them more closely to him. Given the rate at which personnel have been departing the Trump administration, it has arguably not been particularly effective in that regard.

Yet there’s ample evidence that Trump is also a calculated and manipulative liar. The timing of his tweets makes it plain that he frequently uses lies to create media frenzies, to distract from other uncomfortable stories, to whip up his voter base. His lies are thus a form of propaganda, of disinformation.

It’s impossible not to summon to mind, writing all this, the repeated insistence of an apparently guilt-free Boris Johnson that the UK sends £350m a week to the European Union’s coffers, even when the UK statistics watchdog has explicitly told him that this totemic Brexiteer claim is simply wrong.

How to cover shameless, political and calculating liars and propagandists such as Trump (and, on dark days, Johnson) represents an immense and complex challenge for the media. The instinct is to seize on the lie, to “fact check” an individual assertion and demonstrate why it’s wrong. I’ve written plenty of such debunking articles myself of Trump’s various statistical abuses.

Yet if the objective of the lie is to distract, to dictate the news agenda, one can’t get away from the fact that this risks dancing to Trump’s tune.

And what of the impact on the public? Some psychological research hints at a “backfire effect”, where people become more entrenched in their wrong convictions, perhaps fed to them by Trump, when they are exposed to contrary evidence.

The validity of this finding has been contested by other researchers. But nevertheless, it’s pretty clear that truth in America is under the cosh, led by the assaults of its liar-in-chief. Trump’s US support base has not grown since the 2016 election, but it has not collapsed either.

Heartbreaking as it is for liberals to acknowledge, John Stuart Mill’s classic philosophical justification for freedom of expression – “the clearer perception and livelier impression of truth [is] produced by its collision with error” – looks shaky in the face of the empirical evidence of recent years.

So what should the media’s response be? The idea that journalists should simply report blatant lies neutrally along with contrary information, and let audiences make up their own minds, feels to most journalists like a dereliction of a fundamental responsibility to inform and be fair to the public.

One temptation is to take the lies for granted, to focus on policies. I confess I’ve felt that urge at times, when Trump comes out with yet more mendacious rubbish. Is one more debunking really going to achieve anything? But that’s surely an abdication of responsibility, too. For lies on this scale and with this malevolent intent corrupt the public realm and erode our democracy, which ultimately relies on some acceptance of shared truth.

They are an authoritarian attack on pluralist institutions – one that’s disturbingly familiar from the last century of world history. “Contempt for truth goes hand in hand with political oppression,” observes Lee McIntyre of Boston University.

However the media deals with them, we must never deceive ourselves into thinking that the brazen lies of Trump – and the lies of any politician in an open and democratic society – are harmless.

#factchecking #disinformation #backfireeffect #DonalTrump #lies #JohnStuartMill