Back to school

Summary

More or Less (BBC Radio 4)

Episode: Back to School
Date: September 10, 2010
Host: Tim Harford

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Episode Overview

This episode of "More or Less," hosted by Tim Harford, explores the often-misunderstood world of numbers and statistics, as they apply to key societal debates. The main topics covered are the teaching of maths in primary schools, statistics about disability and social inclusion, immigration numbers—specifically student visa figures—and a fascinating counterfactual: what the world population might look like if the First World War never happened.

The tone is engaging, informative, and, as Tim puts it, does for dodgy numbers what the Spanish Inquisition did for religious pluralism.

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Main Segments & Key Insights

1. Rethinking Primary School Maths (00:47–10:40)

The Changing Face of Maths Methods

• New Teaching Methods:

  • Since 1999, the "national numeracy strategy" has recommended new (but not compulsory) ways to teach maths in UK primary schools.
  • Emphasis is on conceptual understanding, multiple solution methods, and moving from mental to formal calculations.

• Laurie Jacks (Maths Consultant):

  • “Ideally, we want all children to have an efficient method of calculating, but at some points along the way, children aren’t quite ready to move on and just learn a process. And actually, what we have now is our children who understand the process and not just know how to do it for a short time…” (01:19)

Testing Adult Reactions

• Listener Panel:

  • Four adults with maths “histories” (Jo, Andy, Clare, Charlotte) try out new methods.
  • Rob Eastaway, author of “Maths For Mums and Dads”, explains:
    • The grid method for long multiplication.
    • The chunking method for long division.

• Panel Experiences:

  • Jo: “All my life I’ve been absolutely petrified of maths, particularly long division.” (02:35)
  • Andy: “I liked times tables… but then... it was scary.” (02:44)
  • Clare: “I got 1% [on an exam] because I just did my name right.” (02:57)
  • Charlotte: “This is my equivalent of bungee jumping.” (03:12)

• Explanation of Methods:

  • Grid Method: Breaks larger multiplications into more manageable chunks (03:32).
  • Chunking: Chipping away at division step by step (04:54).

• Panel Feedback:

  • Jo: “Oh, it was lovely. I really like it. I shall play with this on the train going home. It’s really nice.” (06:05)
  • Andy: “Now I feel I can [help my daughter], with this.” (06:10)
  • Charlotte: “The grid method is the thing that appealed to me because I can finally visualize the way that it could be. I won’t go as far as saying enjoyable, not yet.” (06:36)

Are New Methods Effective?

• Research Update:

  • Little formal research on outcomes.
  • Mickey Harcourt Heath and the University of East Anglia studied 1,000 pupils across 22 schools:
    • “The data definitely shows that children are using much more successfully the new strategies, like the grid method for multiplication.” (08:20)
    • Strategies are seen as more transparent, effective, and linked to understanding.

• Skepticism from Experts:

  • Tony Gardner, University of Birmingham:
    • “The grid method is a lovely idea. Its only shortcoming is it doesn't work as an algorithm. When kids come to implement it, they can’t make it work reliably... The proven method, which there is no reason to ditch, is long multiplication.” (09:26)
  • Dr. Jeremy Hodgson, King's College London:
    • “In a world with calculators, what one really needs is to be able to know how to use a calculator. Now, knowing how to use a calculator is much more than just pressing the buttons.” (10:10)

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2. Disability Stats Scrutinized (11:26–15:05)

The Confusing Numbers

• Listener Question:

  • Charlotte cites a Guardian article stating there are 10 million disabled people in the UK, and that “90% of people had never invited a disabled person into their home.” (11:26)

• Richard Knight Digs In:

  • The 10 million figure is from the Office for Disability Issues, based on the DWP’s Family Resources Survey.
  • The definition is broad (includes any "substantial and long term adverse effect on your ability to carry out normal day to day activities"), and is self-reported (12:35).
    • “Somebody involved in this survey... considered the definition to be about as broad brush as you can get.” (13:24)

• On the 90% Figure:

  • Derived from a Scope/ComRes poll, but with an undefined idea of what "disabled" means—likely interpreted more narrowly by respondents (14:00–14:30).

• Conclusion:

  • “We’re not saying either number’s necessarily dodgy, but quoting them both in the same breath is a little bit misleading because you are talking really about two different groups of people here.” (14:55)

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3. Decoding Immigration Numbers and Student Visas (15:10–20:54)

The Policy Challenge

• Government Target:

  • David Cameron (then PM) vowed to cut net migration below 100,000; by late 2009, it was nearly double that (15:55).
  • Recent focus: a sharp 35% increase in student visas. (16:17)

• Expert Analysis – Mark Easton (BBC):

  • Home Office’s “Migrants Journey” report: Of 2004’s student visa arrivals, 21% remained in Britain five years later.
    • The figure was presented in media as alarming, but:
      • “Far from this 21% figure being something that we should all be really worried about. What the report is saying is this is exactly what we should have expected.” (17:11)

• Legitimacy and Categories of Students:

  • Not all “sub degree” courses are suspect (example: Eton); but many “bogus” institutions have since been purged from eligibility lists (19:49).
    • “...if you come to Britain now on a sub degree course, your institution has to be on something called the highly trusted sponsors list... reduced... from something like 40,000 institutions down to less than 7,000.” (20:54)

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4. Counterfactual: If the First World War Never Happened (21:23–26:31)

Listener Curiosity

• Question from Florence:
  • “What would the world population be today if the First World War had never happened?” (21:23)

Professor Jay Winter Explains the Complexities

• Death Toll Estimates:

  • ~70 million mobilized, 9 million soldiers killed, plus 5 million civilians (mainly Eastern Front), and another million from hardship: “15 million as a direct result.” (22:06)

• Civilian Health Paradox:

  • "One of the paradoxes of the Great War is that the bloodiest, most murderous war in history produced a totally unexpected and unplanned improvement in the standard of living and in the life expectancy of the civilian population." (23:33)
  • Due to rationing and protective policies, civilian life expectancy sometimes improved, particularly post-40 years of age.

• Birth Rate Dip & Unexpected Benefits:

  • Birth rate plummeted, but infant survival improved because midwives, not doctors, managed more deliveries.
    • “I think roughly 100,000 are alive because of the change in obstetric practices.” (25:08)
  • Estimated 1 million fewer births due to war.

• Spanish Flu as a Secondary Impact:

  • "I would say that the 20 million people who died from the Spanish flu, more than twice those who were killed or died in active service, were secondary victims of the First World War." (26:00; see also introduction by Jay Winter at 00:33)

• Population Impact Calculation:

  • Tim Harford sums:
    • 9 million soldiers + 6 million civilians + ~1 million fewer births = 16 million
    • Add 2 million (10% of Spanish flu) as a conservative secondary impact = 18 million
    • WWI reduced the world population by about 1%.
    • Today, the world population would be about 69 million higher—“a little more than the entire population of the UK.” (26:31)

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Notable Quotes

• Tim Harford, episode opening:

  • “...the programme that does for dodgy numbers what the Spanish Inquisition did for religious pluralism. You didn’t expect that, did you?” (00:05)

• Laurie Jacks, on modern maths education:

  • “What we have now is our children who understand the process and not just know how to do it for a short time, and then it gets pushed into the back of their memory and ultimately lost in adulthood.” (01:19)

• Panelist Charlotte, on self-image and maths:

  • “I’m the proud possessor of an unclassified in mat O level. So this is my equivalent of bungee jumping.” (03:12)

• Rob Eastaway, on maths anxiety:

  • “That sense of getting it wrong in front of other people is a really horrible one. We all feel you’ve got to create the culture in which it becomes something you investigate together and you explore. And when you get things wrong, you discover why...” (06:49)

• Tony Gardner, on the grid method:

  • “The grid method is a lovely idea. Its only shortcoming is it doesn’t work as an algorithm... When you want to master a general algorithm… the proven method… is long multiplication.” (09:26)

• Professor Jay Winter, on the war’s paradox:

  • “The bloodiest, most murderous war in history produced a totally unexpected and unplanned improvement in the standard of living and in the life expectancy of the civilian population.” (23:33)

• Tim Harford, on the population cost of WWI:

  • “The world population today is about 6.9 billion. If we assume the same average population growth since 1918, with or without the First World War, then the world's population would be 1% higher today, 69 million more people, a little more than the entire population of the UK.” (26:31)

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Segment Timestamps

• 00:47–10:40: Primary school maths methods
• 11:26–15:05: Disability statistics in the UK
• 15:10–20:54: Immigration and student visas statistics
• 21:23–26:31: World population “what if” – impact of the First World War

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Summary

This episode demystifies the numbers behind current debates in education, inclusion, migration, and history. The hosts and guests emphasized that while numbers can illuminate issues, context, definitions, and motives often distort their meaning. Whether exploring new methods for teaching multiplication or examining statistics on disabilities or migrants, "More or Less" insists on careful scrutiny and thoughtful interpretation. The historical section offers a sobering—and surprisingly hopeful—look at how even the darkest events can have unexpected consequences for population and health.

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For more, check out the More or Less website and Rob Eastaway’s video tutorials on the BBC site.

Transcript

[Tim Harford]

Thank you for downloading this week's More Or Less podcast. Here's Tim Harford.

Hello and welcome to More Or Less, the programme that does for dodgy numbers what the Spanish Inquisition did for religious pluralism. You didn't expect that, did you? This week, we unpick the statistics on disability and on immigration and we ask what's happening to primary school maths? And we'll try to work out what the world population would be today if the First World War had never happened. Not easy. In fact, it's hard even to figure

[Richard Knight]

out what the war did to the

[Tim Harford]

world's population back then.

[Professor Jay Winter]

One of the paradoxes of the Great War is that the bloodiest, most murderous war in history produced a totally unexpected and unplanned improvement in the standard of living and in the life expectancy of the civilian population.

[Tim Harford]

But first, as the nation's school children get used to being back in the classroom after their long summer break, we've decided to take a closer look at what they'll be learning there. Most parents simply wouldn't recognise the way their children are being taught mathematics in primary school. Although the current methods were introduced through the national numeracy strategy in 1999, they're not compulsory, but they were recommended and are widely used. I spoke to Laurie Jacks, until recently mathematics coordinator at a primary school and now an independent mathematics consultant.

[Laurie Jacks]

Ideally, we want all children to have an efficient method of calculating, but at some points along the way, children aren't quite ready to move on and just learn a process. And actually, what we have now is our children who understand the process and not just know how to do it for a short time, and then it gets pushed into the back of their memory and ultimately lost in adulthood.

[Tim Harford]

The basic idea is, first, to teach children that there's more than one way

[Richard Knight]

to skin a cat when it comes

[Tim Harford]

to sums, and second, to give children a way to calculate intuitively in their heads before moving on to more formal pen and paper methods. Laurie Jacks thinks that school children cope very well with the new methods, but we were interested to see how adults would take to them. We assembled a panel of loyal listeners, each of whom had responded to our request last week. For people who felt that primary school maths had simply passed them by, we had a huge response with some very moving stories. For those to whom we've not had a chance to reply, we apologise. Then we asked Rob Eastaway, the author of a new book, Maths For Mums and Dads, to explain the new methods. The grid method for long multiplication and the chunking method for doing long division. And so Rob and our four brave souls gathered together in central London.

[Jo]

My name's Jo, I've come from Essex. All my life I've been absolutely petrified of maths, particularly long division.

[Andy]

Hi, I'm Andy from South London. I quite liked maths at primary school, actually. I liked times tables and things like that when you could sing along to it. But then I've sort of avoided it because it's any more complicated than that. It was scary.

[Jo]

Hello, I'm Clare Murray, I live in Norfolk and I've always been bad at maths, ever since I was about 10 and failed my exam. I got 1% because I just did my name right. I didn't do anything. I was lost, completely lost. Maybe I'll learn something today.

[Charlotte]

I'm Charlotte from London. I'm the proud possessor of an unclassified in mat O level. So this is my equivalent of bungee jumping.

[Tim Harford]

Rob began by explaining the grid method for long multiplication. It starts with what Rob calls an array, which is basically a bunch of dots gathered together in the shape of a rectangle.

[Rob Eastaway]

This is a picture of a crate of bottles. You can just have between this. The starting point for multiplication these days is actually to start with an array and just do dots in an array. You could obviously count them, but very quickly realize, well, actually there's my tables involved here, seven rows of 8, 7, 8, 56. And that's how to start with a multiplication. Now let's do seven times 14. We could actually do that as an array. So you're going to end up with this array of seven dots, seven rows and 14 dots. Now, you could count those up, but can you see that you can actually split this box of dots up so that Instead of saying seven times 14, you could divide it into 10 and four. So you could say, well, seven times 10. Everyone do that in their heads, seven and then what's left? Well, seven times four.

[Tim Harford]

Our panel seemed to find the grid method reasonably intuitive, particularly with a bit of practice. So Rob moved on to what is to many a much harder problem, long division. I know I used to be able to do it, but these days I just reach for the calculator. Children are now taught to do long division through what's called chunking, a practice which sounds like it's illegal in several US states. In fact, chunking is a sort of improvised method of chipping away at the division problem a chunk at a time. Here's Rob Eastway again.

[Rob Eastaway]

Let's Take the sum I gave you at the beginning there was 322 divided by 14. And let's suppose this time it's 322 sweets and we're putting 14 in every bag. How many bags are we going to need? So I'm going to take away a chunk of 10, because I know 10 lots of 14 is 140. I've already taken 10 bags away. How many does that leave me with?

[Jo]

So you could do that again and get another 140? Yeah, 280.

[Rob Eastaway]

So I've taken 140 and I work out what I've got left, which is 182, and I can take, as Claire so rightly says, I could take another 140 away from that. So I've taken another bunch of 10. So so far I've taken 20 bags away from this and I'm left now with 42.

[Jo]

I'm with you. Right, yes, yes. Yeah.

[Rob Eastaway]

Okay, so we've got 42 left. Does everyone agree?

[Andy]

Yes.

[Rob Eastaway]

So how many more bags can we take away?

[Jo]

You can do at least three. Yeah.

[Rob Eastaway]

You can take, in fact. Three. 14, 42, exactly.

[Jo]

Oh, is it.

[Rob Eastaway]

That's. That's handy, isn't it?

[Tim Harford]

So, what did our brave panelists make of Rob? The grid method and chunking.

[Jo]

Oh, it was lovely. I really like it. I shall play with this on the train going home. It's really nice.

[Andy]

It really hit me when I was helping my daughter with her homework. I said, oh, yeah, I'll help you with your long multiplication. It was sat there and showed her how to do it and there was this pause and she just said, no, that's wrong, isn't it? And we had to go and get a calculator and it was wrong. I don't help her anymore, so now I feel I can with this.

[Jo]

It's been very interesting. It's been very interesting to realise that you don't have to do it just one way.

[Charlotte]

Yes, it's certainly interesting. I think also I enjoyed the visual side of it. The grid method is the thing that appealed to me because I can finally visualize the way that it could be. I won't go as far as saying enjoyable, not yet.

[Rob Eastaway]

You're incredibly brave people for coming in because so many adults kind of bury these feelings about math and don't actually dare to, you know, that sense of getting it wrong in front of other people is a really horrible one. We all feel you've got to create the culture in which it becomes something you investigate together and you explore. And when you get things wrong, you discover why you've got it wrong and you don't get punished or laughed at for it.

[Tim Harford]

Rob Eastway there, author of Maths for Mums and Dads. Of course, Rob's tutorial lasted far longer than the few minutes we're able to devote to it in this program. So if you couldn't follow it, and I wouldn't blame you, there's a video tutorial presented by Rob just for more or less listeners on our website BBC.co.uk more or less. But at this point, we have to ask the awkward question, are these newfangled methods actually any good? Or rather, has anybody bothered to find out whether they've raised standards since they were introduced in 1999? Little research has been done. My original script said. Surprisingly little research has been done. But to the more or less team, such things are sadly not surprising at all. We spoke to Mickey Harcourt Heath. She leads a team of local government maths consultants in Norfolk. They couldn't find any evidence, so along with the University of East Anglia, they conducted their own. With almost 1,000 children randomly selected from a broad range of 22 schools, the children were given some sums. Then the researchers looked at the methods the children chose and whether they produced the right answer.

[Laurie Jacks]

The data definitely shows that children are using much more successfully the new strategies, like the grid method for multiplication. And I think alongside that, there's definitely been a better understanding, not just by teachers but by parents as well, of the progression in those skills. And I think it's become really clear that those strategies are transparent for children. Not only are they effective and efficient, but children can see what they've done and they are linked very clearly to mathematical understanding.

[Tim Harford]

Mickey Harcourt Heath but while a little evidence is better than none, the fact that the children who use the new

[Richard Knight]

methods also tend to get the answers

[Tim Harford]

right isn't really conclusive.

[Richard Knight]

Perhaps they're just the ones paying attention in class.

[Tim Harford]

Perhaps they'd also get the answer right with the old methods. It's hard to say for sure. There are critics of the new methods, such as Tony Gardner, a reader in mathematics and mathematics education at the University of Birmingham. He has no quarrel with chunking, but he's no fan of the grid method, which he says breaks down with larger numbers and harder sums.

[Tony Gardner]

The grid method is a lovely idea. Its only shortcoming is it doesn't work as an algorithm. When kids come to implement it, they can't make it work reliably. When you want to master a general algorithm, that will allow you to calculate any multiplication at all. The proven method, which there is no reason to ditch, is long multiplication. It's a very effective way of exploiting place value and of keeping numbers in their columns. The grid method ordinary English kids these days cannot handle because there is no column structure in the layout and they get confused.

[Tim Harford]

Tony Gardner of the University of Birmingham and Dr. Jeremy Hodgeon, senior Lecturer in Mathematics Education at King's College London, thinks we might be missing the wider point. Do we even need to learn these sorts of skills anymore?

[Jeremy Hodgson]

Understanding multiplication isn't simply about being able to do it, it's about being able to use and estimate. In fact, when we look at what adults need, they don't really need to do pencil and paper calculations. In a world with calculators, what one really needs is to be able to know how to use a calculator. Now, knowing how to use a calculator is much more than just pressing the buttons.

[Tim Harford]

Jeremy Hodgson and of course, the question hanging over these methods which were introduced in Tony Blair's first term, is what the new coalition government plans to do with them. That's not clear. The government plans a curriculum review in the autumn, but for now they didn't have much to say to us about what plans they have, if any. If they do want to introduce some funky new methods, never fear, Singaporean school children are even now using double number lines and ratio tables. And no, we don't know what they are either. You're listening to More or less. In association with the Open University, I'm Tim Harford. Not everyone who emailed us last week did so to confess poor long division skills. Sally Heafer wanted us to investigate a Guardian article in which she says there

[Charlotte]

were some odd sounding stats I wish you would dig into. It said there were 10 million disabled people in the UK and illustrated the social isolation and discrimination they faced by claiming 90% of people had never invited a disabled person into their home. The article was illustrated with a picture of a woman in a wheelchair. 10 million seemed a high number to me as it's roughly 1 in 6 of the population. I wonder how disability was defined in this article.

[Tim Harford]

Well, our producer Richard Knight has been

[Richard Knight]

looking at these numbers.

[Tim Harford]

Rich, what have you found?

[Richard Knight]

Well, Sally pointed us to this Guardian piece which claimed there to be 10 million disabled people in Britain and it turns out that number does come from an official source. It comes from the Office for Disability Issues. And that number in turn is taken by them from the DWP who publish a large annual report called the Family Resources Survey.

[Tim Harford]

So this is the Department for Work and Pensions. How do they do that survey? Because the details usually matter here.

[Richard Knight]

Well, they phone up a sample of people and ask them a whole bunch of questions about their circumstances, their employment, their income and so on. They also do have a chapter on disability. So they ask people, are you disabled?

[Tim Harford]

Do they give them any guidance in how to answer that question?

[Richard Knight]

They do. They say, are you disabled? According to the definitions applied by the Disability Discrimination Act. The act does give a very specific definition of what it is to be disabled. It says you are disabled if you have a physical or mental impairment that has a substantial and long term adverse effect on your ability to carry out normal day to day activities. And then in clarifications further on, it says day to day activities might include eating, walking, washing, shopping and relevant capacities are mobility, manual dexterity, speech, hearing, seeing and memory. That's fair enough. But the survey is of course self reported. You're phoned up and asked, are you disabled? According to that criteria, it's up to you to decide whether you are or not. And somebody involved in this survey, a DWP person, did tell me that they considered the definition to be about as broad brush as you can get. Those were his words.

So presumably then, this is rather subjective and somebody with, for instance, a chronic bad back been going on for more than a year could well report himself or herself as being disabled.

He could well do that, and that might very well be reasonable. Bad backs can of course be really incapacitating, but I suspect that's not the kind of thing Sally has in mind when she thinks about what it means to be disabled. And I think that's why the figure looked really high to her.

The Guardian put together these two different figures.

[Tim Harford]

One was about the number of disabled

[Richard Knight]

people and the other was this quite shocking claim about the number of people who've ever invited a disabled person into their home.

That 90% figure was taken from a poll conducted by Scope, or at least commissioned by Scope, the disability charity, and conducted by Comrades, the pollsters. Now, we've looked at the raw data. When they ask the question of their respondents, have you ever invited a disabled person into your house for a social occasion? They don't qualify what it is to be disabled and I think it's probably a pretty safe bet to suggest that the definition in the minds of many of those polled on that occasion, would have been a lot narrower than the definition supplied by the DWP to the people they phone up.

Yeah, because you've got these two very different definitions. Here one is you are encouraging people to self report their own disability status, given a very broad brush definition. And the second question, you just say, well, have you ever invited a disabled person into your home? People may well think of more stereotypical definitions of disability, more visible signs of disability. Did the person have a guide dog? Was the person in a wheelchair? And we're really just not comparing like with like.

Yeah. So we're not saying either number's necessarily dodgy, but quoting them both in the same breath is a little bit misleading because you are talking really about two different groups of people here.

[Tim Harford]

Well, thanks, Rich.

[Richard Knight]

Isn't Wesley Stevenson supposed to be the reporter in this series, by the way?

Well, he was, Tim, but remember he was killed last week by a freak sound effect.

[Tim Harford]

Oh, yes, I forgot. Thanks to Sally Heaver for that question. If you'd like to write to us, you can do so at more or lessbc.co.uk or via our website BBC.co.uk more or less. Or tweet at me, Tim Harford on Twitter and I will slavishly forward your question to the team. Now, the Home Office Minister Damian Green gave his first major speech on immigration this week and shot out some interesting figures about student visas. These visas appear to be his latest target in his attempt to bring down net migration. During the election campaign, David Cameron committed the new government to bringing net migration below 100,000. At the end of last year, it was nearly twice that.

[Richard Knight]

Net migration is the difference between those

[Tim Harford]

coming into the country for more than a year minus those leaving the country for more than a year. Now, the BBC's home editor, Mark Easton, has raised a few concerns about the task the government has set itself and the way this week's figures have been reported. So I went to find him in the BBC newsroom. I began by asking whether Damien Green had been set a target that was hard to hit.

[Mark Easton]

I think he's got a bit of a problem. That figure of net migration is a factor of many, many things. And while the previous government, and to some extent this current government, has been quite successful in squeezing the numbers of non EU workers coming into the uk, there's another element which has suddenly popped up which, which is student visas. We saw in the last quarter a fantastically big increase of 35% in the number of student visas being issued. And so what we saw with Damian Green was, yes, a continued commitment to reduce the net migration figure to below 100,000, a recognition that just squeezing the workers, bit of it is not going to be enough. And so he's having to turn his attention to those students.

[Richard Knight]

You've blogged about this and you were concerned with the way that Damian Green's speech was reported in some of the newspapers.

[Mark Easton]

The Home Office published an excellent report called the Migrants Journey, which looked at a cohort of migrants who came to Britain, I think, in 2004 and asked the question, where are they, in fact in 2009. And the home Office selected from that document the fact that of those people who'd arrived on a student visa in 2004, 21%, a fifth, were still in Britain in 2009 and they kind of left it there. The question is, well, what conclusion are we to draw from this figure? I think there was a sense in which just saying a fifth of them are still here five years on was to invite people to say, oh, that sounds absolutely appalling. Actually, the original report from which that figure comes comes to a very different conclusion about that 21% figure. Let me read actually what the report says. It says the findings relating to the study route appear to be consistent with the pattern expected for students coming to the uk. And they make the point that a small proportion of students on one year courses leave the system fairly early, while those on mid length courses graduate postgraduate degree and so on, are likely to remain for three years or more. And that a small proportion remain in the system as a student in 2009 having been on perhaps long term career education like medical students, or having taken more than one course of study so far from this 21% figure being something that we should all be really worried about. What the report is saying is this is exactly what we should have expected.

[Richard Knight]

But if the students have left the visa system, has the Home Office then assumed that they've left the country and do we know that they have left the country?

[Mark Easton]

No, we don't. And there will be some, I'm sure, even now, despite very tight controls on all of this, who come to Britain to study and stay illegally hiding from the authorities, you know, for some time afterwards. The thing is though, that the thing that we worry about, illegal migration is not going to be affected by the government determination to reduce the net migration figure to below 100,000.

[Richard Knight]

One of the things that Damian Green was concerned about was, or seems to be concerned about, was how many of these courses were really legitimate, how many of these students were really students? Now, you pointed out in your blog post that students studying for A levels at Eton, David Cameron's alma mater, would count as foreign students studying for sub degree courses. But we're mostly not talking about Eton here. A lot of back alley, up the stairs, institutions that aren't fully accredited.

[Mark Easton]

I think that certainly has been a real problem. My point in the blog was trying to make out there was a suggestion again, I think in the language that was used, that anybody who was studying in Britain at sub degree level was somehow a bit dodgy. My point was, look, that's just clearly illogical. I mean, there are lots of students who are here at private boarding schools from all over the world who are not dodgy in the least are bringing valuable cash into the country. But you're right, the vast majority of those who are here at sub degree level are coming to study at colleges, a number that have been proved to have been completely bogus. They were really just fronts for people to get round the immigration system over the last few years. The previous government was still tightening up the rules on that. If you come to Britain now on a sub degree course, your institution has to be on something called the highly trusted sponsors list held by the Home Office. It's been reduced, I think, from something like 40,000 institutions down to less than 7,000. So those things have been changed.

[Tim Harford]

The BBC's home editor, Mark Easton, Mark, who all by himself has won twice as many journalism awards from the Royal Statistical Society as the entire more or less team, has written more about this on his blog. And there's a link from our website, BBC.co.ukmoreorless this week we've been commemorating the 70th anniversary of the start of the Blitz. But our young but loyal listener, Florence Hewitt, had an earlier war in mind when she wrote to us over the summer.

We were watching the film oh, what a Lovely War and they were flashing up the number of men who died in every battle. I just couldn't believe the numbers. If you just added up all the Allied losses, it was hundreds of thousands. It made me wonder what the population worldwide would be today if the war had never happened.

A good question. And to some extent it's imponderable. I mean, if the First World War had never happened, would the Second World War have happened? The Russian Revolution? The Cold War, The Great Leap Forward in China? But even limiting ourselves to the question

[Richard Knight]

of how many soldiers died in the

[Tim Harford]

Great War, there's some homework to do. Fortunately, Professor Jay Winter, author of the Great War and the British People, has done it. I spoke to him down the line from Paris.

[Professor Jay Winter]

The question about the number of men who died in the First World War is one of the hardest ones to. The reason is Partly, the enormity of the war, the sheer size and scale of it, made accounting impossible at the time. But if we try to estimate, we can assume of the 70 million men who put on a uniform in the First World War, 9 million were killed. But that isn't enough, because the war produced chaos in Central Europe and in Eastern Europe on a greater scale than in the West. In the west, it was a war between armies, but in the east it was war, civil war and revolution together. And it is probably the case that another 5 million civilians were killed in the Eastern Front, which was a 19th century war fought with 20th century weapons and 19th century or 18th century medicine. In addition, shortages, hunger, miserable conditions, overwork, fear, anxiety over loved ones, produced an increase in civilian deaths in Central and Western Europe. So another million would go there. And I would put the number of people who died as a result of the First World War directly at 15 million.

[Tim Harford]

Now, what about the population back home?

[Richard Knight]

I mean, to take a British perspective

[Tim Harford]

for a moment, were people less healthy because of the chaos?

[Richard Knight]

Were they more healthy because there was

[Tim Harford]

greater medical attention available? What's the story?

[Professor Jay Winter]

One of the paradoxes of the Great War is that the bloodiest, most murderous war in history produced a totally unexpected and unplanned improvement in the standard of living and in the life expectancy of the civilian population. Part of the reason were rations, which meant that everybody had a chance to a decent basket of consumables. And maternal and child health was defended because the biological characteristics of the population were strategically important. There was an improvement in the well being of the population that happened independently of the fact that almost all of the general practitioners were away from the civilian population. So fewer doctors meant better health.

[Richard Knight]

And my understanding is you examined this

[Tim Harford]

by looking at insurance records.

[Professor Jay Winter]

Yes, they make calculations about how much you should pay per month, how much the premium should be on the likelihood of your dying between the age of 30 and 31, and so on. Using those, I was able to estimate the number of people who would have died had there been no war. And the results produced the statistics of casualties for Britain that resulted in my estimation of three quarters of a million British men who died. But it also produced the puzzling paradox that after the age of 40, the number of people who would have died had there been no war was higher than the number of people who actually died. And that meant there was an improvement in civilian health.

[Tim Harford]

Now, we've been talking about death rates, but of course birth rates would also be affected.

[Richard Knight]

With so many young men off at

[Tim Harford]

the front, what was happening to birth rates.

[Professor Jay Winter]

By and large, the birth rate plummeted. But one of the puzzling features of the First World War was the chances of survival of infants improved. And one way to understand that is that the practice of midwifery took over from doctors, who frequently used force. The fact that doctors did not organize deliveries probably saved the lives of infants who otherwise would have been damaged. I think roughly 100,000 are alive because of the change in obstetric practices. My guess is that there would have been 1 million more babies born had the First World War not taken place. But the important thing to recognize is that the experience of Britain was different from the experience of most countries in the war, where civilians suffered as much as soldiers did.

[Tim Harford]

Or what about Spanish flu? And should we blame the Spanish Flu on the First World War?

[Professor Jay Winter]

I would say that the 20 million people who died from the Spanish flu, more than twice those who were killed or died in active service, were secondary victims of the First World War. That is to say, had the First World War not happened, mutant viruses would have occurred. They occurred long after. But they wouldn't have had that astonishing power that they did in the two waves in 1918 and 1919 that hit so many, so hard and provided a devastating second wave of bereavement to a world already in mourning.

[Tim Harford]

Professor Jay Winter. Adding up these truly awful numbers, I make it 9 million soldiers killed and 6 million civilians killed, mostly on the Eastern Front. Probably a million fewer children were born. That's a total of 16 million fewer people. Add 2 million, a rather conservative 10% of the death toll from the Spanish flu, and you get to 18 million. While civilian health in the UK improved. That's a rounding error compared with the horrors on the mainland. We spoke to the United Nations Population Division and they estimate that the world population on the eve of the war was about 1.8 billion. So the war reduced world population by 1%. The world population today is about 6.9 billion. If we assume the same average population growth since 1918, with or without the First World War, then the world's population would be 1% higher today, 69 million more people, a little more than the entire population of the uk. That's all we have time for this week. As always, you can check out our website, BBC.co.uk more or less. You might also try to listen to this week's Moneybox. They've been dealing with a story from the Royal Statistical Society itself. Apparently, it's about money. We'll be back next week. Until then, goodbye.

More or less was presented by Tim Harford, the FT's undercover economist. The producer was Richard Knight and the editor was Richard Varden. It was made in association with the Open University.