"This is a post long on problems and short on solutions".
Thank you for having the modesty not to suggest solutions. I wish more people did.
Often pointing out the issue in itself leads to mitigations while many proposed solutions (Marx etc) disastrous.
I wondered how successful a society would be where you can self select to either point out problems or to suggest a solution. Then i remembered we call them "The loyal Opposition" and "The government" and its been going quite well for longer than most other societies.
Thanks for writing this (or I guess, thanks to the paid subscribers!). One of the most significant problems facing humanity today, and under discussed and under appreciated.
Footnote 14 ends mid sentence (and thought)
glory.Partygate is either looking for a space or a .com at the end.
"Much of this was done in the name of the Public Sector Equality Duty [which] requires public institutions to "
"Based on the results - a society increasingly polarised [on] political, identity and cultural matters"
"with housing perhaps in this case in the UK" should lose the first in, or swap case for state.
"We should certainly take care [something is missing here] does not lead us to embrace"
I don't understand why schizophrenia rates are up 67% in the chart you share. I thought schizophrenia was very genetic, and should be very stable? I admit this isn't very relevant to your hypothesis, other than throwing doubt on the veracity of the chart.
Re schizophrenia, I am not remotely an expert, but the NHS doesn't think that schizophrenia is entirely genetic but claims it is a 'combination of physical, genetic, psychological and environmental'.
There are lots of other charts by Haidt and other data people (Twenge, Burn-Murdoch) that show the core lines going the same way, so I'm not that doubtful about the veracity:
Twin studies show schizophrenia is 80% genetic, which I claim matches my 'very genetic' claim. You say 'the NHS doesn't think that schizophrenia is entirely genetic', and of course they don't - it isn't, and I wasn't claiming it was. But it would take something seriously funky in the environment to produce a 67% increase in something that is 80% genetic. As a result overdiagnosis is by far the most likely explanation.
This is what I was getting at in challenging the veracity of the chart. I don't mean "someone literally typoed all these numbers", I mean "if the number that is likely to be extremely stable is showing as up 67% due to overdiagnosis, then there's a good chance the other numbers in this chart are distorted by overdiagnosis".
I don't think this is the whole of the effect (the other diagnoses are up by more than 67%, and I think suicides are also up), but spotting it altered my perspective from "my word mental health among the young is in free fall" to "my word overdiagnosis of mental health conditions is strapped to a rocket, and also real mental health is getting a bit worse".
I've checked WebMD and they agree with your stat. That's quite disappointing of the NHS website to downplay the genetic element so much.
Yes, I fully agree that over-diagnosis is playing a big role here, and that there is also some actual mental health getting worse too (and this matches the less genetic ones going up more). They may also be feeding off each other (you are on the edge of formal depression, get diagnosed as it and then are able to sign up for welfare with no work requirements; as a result of the isolation, your mental health tips over into full-blown depression).
From a 'having children' perspective, it may also be that overdiagnosis and changing attitudes are important alongside any rising real cases (if someone believes they have ADHD and alters their life choices because of it, that's an impact that may make them less happy and less likely to have children, even if they wouldn't have met the criteria for diagnosis a generation ago).
I wouldn't be so hard on the NHS web-site. "Heritability", or "proportion of disease risk 'explained' by genetic factors", is quite a complicated concept so saying "this disease is 80% genetic" could be more misleading to many people than just saying what they do say (combination of physical, genetic, psychological and environmental - which is accurate).
You can reduce the 80% number just by increasing the variance in the environmental factors, without affecting the genetics at all, because heritability is defined as a variance ratio. This isn't very intuitive IMO.
As a real example of this, when most of the population smoked cigarettes, the proportion of heritability of lung cancer attributable to genetics was low. As smoking prevalence drops, the proportion of heritability due to genetics rises.
Yes, this. I find heritability percentages very unintuitive, especially since they don't max out at 100%. I'd be inclined to give the NHS (and WebMD, which is similarly woolly about the causes and just says "*can* run in families", https://www.webmd.com/schizophrenia/mental-health-schizophrenia) the benefit of the doubt.
Is it really a stretch for the NHS to take as a context conditions in the UK at the time of writing the article? To say it's fair enough to be vague when stating facts if that fact varies by time and place would justify saying "it's hard to say whether there are between 65m and 75m people in the UK today, and the population has varied over history, and today varies by country".
Do you really believe that they couldn't easily provide the reader with considerably more information by writing something like "mostly genetic, but physical, psychological and environmental factors also make some contribution"?
I couldn't imagine writing something so unnecessarily vague unless I couldn't be bothered to check what the truth was, or I didn't want to admit what the truth was.
I'm not sure if your numbers are right. If the TFR is 1.0, then each parent has (on average) 1 child, who have on average 0.5 children. So each grandparent has on average 0.5 grandchildren. If the TFR is 1.4, then each parent has (on average) 1.4 children, who have on average 1.4*0.7 = 0.98 children. So 100 randomly selected grandparents have 98 children. Your numbers work if you mean 50 grandparent couples, but if you mean 100 unrelated grandparents, I think you are out by a factor of 2. So maybe it's that we mean different things, but it's not as bleak as I understood from my reading of your numbers!
I don't follow your reasoning. You seem to be double-counting the children in the first generation, but only single-counting the ones in the second.
Either approach could make sense for different purposes, but not mixing them.
I think the approach Edrith is using here is more usual and makes sense in this context. Although I have two children, they're the same two children my husband has, so I've only replaced myself with 2*0.5 = 1 person, not 2.
If the TFR is 1, then for every 100 adults in generation N, there will only be 50 children in generation N+1. This multiplies up across the whole population. If you decide to look at a group of 100 unrelated people and say they actually have 100 children, then you also have to say that the group of their 100 partners has 0 children (because you already counted those children to the first partners), so overall there's only 100 children from 200 adults.
So the number we're really interested in here is how many people are there in Gen(n+2) for every 100 people in Gen(n). I'm confident my numbers are correct in terms of describing this
I find the 'grandchildren' framing a useful way of communicating this simply (can't claim credit as have seen it used elsewhere) as a lot of people find TFRs non-intuitive.
I framed it as 'Every X Taiwanese can expect Y grandchildren between them' to try to make clear we were talking about populations, not counting how many grandchildren a specific person had, to avoid the double-counting you refer to. I'd welcome any suggestions on reframing that keep the simplicity but avoid ambiguity.
P.S. I think Rachael is right in that in your example you've double-counted the children in the first generation and single-counted in the second. In the simple case where TFR = 1 because everyone has precisely 1 child, everyone of the relevant generation is a grandparent and all of them have precisely 1 grandchild, not 0.5.
I think we are reaching understanding here, if not consensus. There is a natural double counting of children at the next generation, as you count not only your children, but also your spouse's children. If I say: you have 2 children, that is correct. If I say: your spouse has 2 children, that is correct. But together, you have 2 children, not 4 children.
But there is a natural single counting at each subsequent generation, you count only your children's children.
The simple phrasing is that a TFR of 1 means that for every 100 people of the current generation, there will be 50 in the next generation. But if you use the parenting phrasing, every 100 fathers in the current generation will have on average 100 children. And every 100 mothers in the current generation will have on average 100 children. So it seems reasonable to say that every 100 parents in the current generation will have on average 100 children. Each child is counted twice - but that is how we count children! They belong to both the father and the mother.
My assertation is that your numbers are correct for describing the numbers of members of each generation, but that they are incorrect for the way in which I have read and understood the statement. I think my way of reading the statement is a natural one, and yours is convoluted. For me, at best it's an ambiguous phrasing - although granted, a more emotive one.
> But there is a natural single counting at each subsequent generation, you count only your children's children.
Actually, scratch that. You are right - if I'm double counting at one generation, then I should be double counting at all generations. TFR of 1 means that on average, every person will have on average 1 child, 1 grandchild, 1 great-grandchild, and so on ever more. But nevertheless, the population is shrinking as each of those children is double-counted, each grandchild is quadruple-counted, and so on.
It's definitely helpful to know that you read it a particular way!
The grandchildren phrasing is definitely emotive, but it also really clearly conveys the time period, which is why I like it. Some people have different views of what a generation is (and e.g. Gen X, Millennial, etc. are only 15 years long).
I think an unambiguous phrasing that keeps grandchildren is, 'for every 100 Koreans today, their will only be 11 people in their grandchildren's generation.'
It won't solve the overall fertility replacement crisis, but I have a policy that would get you more of the people you most want to have.
Make having two of your own children over the age of five living with you a prerequisite for enrolment at universities. Three children, ditto, for grad programs. The carrot: make university free for those accepted. All costs, including for the children.
What's that? Overton Window? Yeah, heard of it. It's a long way away from here, though. Never seen it. I heard it's drifting this way, though. Due to get here in a hundred years.
However, one could conceivably think of other benefits that directly help young parents. Why not give them the first right to certain new (bigger) apartments when they have one child more? Why not either pay them directly more and for longer, or lower social security and tax contributions massively for them as long as their kids are young? Why not tie the value of your old-age pension (at least partly) to the number of kids you raised? And so on.
These are all things that are actually very directly connected with families and raising kids and so far we've always shied away of also reflecting that in our societies. Maybe we ought to start to.
I'm aware of the Overton window and of course you can try to shift it.
The options im proposing are also pretty radical and haven't been tried yet to a full extent. A €200 monthly bonus is a far cry from a €2,000 tax credit per month. And so on.
"This is a post long on problems and short on solutions".
Thank you for having the modesty not to suggest solutions. I wish more people did.
Often pointing out the issue in itself leads to mitigations while many proposed solutions (Marx etc) disastrous.
I wondered how successful a society would be where you can self select to either point out problems or to suggest a solution. Then i remembered we call them "The loyal Opposition" and "The government" and its been going quite well for longer than most other societies.
Thanks for writing this (or I guess, thanks to the paid subscribers!). One of the most significant problems facing humanity today, and under discussed and under appreciated.
Footnote 14 ends mid sentence (and thought)
glory.Partygate is either looking for a space or a .com at the end.
"Much of this was done in the name of the Public Sector Equality Duty [which] requires public institutions to "
"Based on the results - a society increasingly polarised [on] political, identity and cultural matters"
"with housing perhaps in this case in the UK" should lose the first in, or swap case for state.
"We should certainly take care [something is missing here] does not lead us to embrace"
I don't understand why schizophrenia rates are up 67% in the chart you share. I thought schizophrenia was very genetic, and should be very stable? I admit this isn't very relevant to your hypothesis, other than throwing doubt on the veracity of the chart.
Thank you! And wow, what a lot of typos.
Re schizophrenia, I am not remotely an expert, but the NHS doesn't think that schizophrenia is entirely genetic but claims it is a 'combination of physical, genetic, psychological and environmental'.
https://www.nhs.uk/mental-health/conditions/schizophrenia/causes/
I also found (in a very brief search) a John Hopkins report suggesting there was overdiagnosis.
https://www.hopkinsmedicine.org/news/newsroom/news-releases/2019/04/study-suggests-overdiagnosis-of-schizophrenia
There are lots of other charts by Haidt and other data people (Twenge, Burn-Murdoch) that show the core lines going the same way, so I'm not that doubtful about the veracity:
https://www.anxiousgeneration.com/research/the-evidence
Twin studies show schizophrenia is 80% genetic, which I claim matches my 'very genetic' claim. You say 'the NHS doesn't think that schizophrenia is entirely genetic', and of course they don't - it isn't, and I wasn't claiming it was. But it would take something seriously funky in the environment to produce a 67% increase in something that is 80% genetic. As a result overdiagnosis is by far the most likely explanation.
This is what I was getting at in challenging the veracity of the chart. I don't mean "someone literally typoed all these numbers", I mean "if the number that is likely to be extremely stable is showing as up 67% due to overdiagnosis, then there's a good chance the other numbers in this chart are distorted by overdiagnosis".
I don't think this is the whole of the effect (the other diagnoses are up by more than 67%, and I think suicides are also up), but spotting it altered my perspective from "my word mental health among the young is in free fall" to "my word overdiagnosis of mental health conditions is strapped to a rocket, and also real mental health is getting a bit worse".
I've checked WebMD and they agree with your stat. That's quite disappointing of the NHS website to downplay the genetic element so much.
Yes, I fully agree that over-diagnosis is playing a big role here, and that there is also some actual mental health getting worse too (and this matches the less genetic ones going up more). They may also be feeding off each other (you are on the edge of formal depression, get diagnosed as it and then are able to sign up for welfare with no work requirements; as a result of the isolation, your mental health tips over into full-blown depression).
From a 'having children' perspective, it may also be that overdiagnosis and changing attitudes are important alongside any rising real cases (if someone believes they have ADHD and alters their life choices because of it, that's an impact that may make them less happy and less likely to have children, even if they wouldn't have met the criteria for diagnosis a generation ago).
I wouldn't be so hard on the NHS web-site. "Heritability", or "proportion of disease risk 'explained' by genetic factors", is quite a complicated concept so saying "this disease is 80% genetic" could be more misleading to many people than just saying what they do say (combination of physical, genetic, psychological and environmental - which is accurate).
You can reduce the 80% number just by increasing the variance in the environmental factors, without affecting the genetics at all, because heritability is defined as a variance ratio. This isn't very intuitive IMO.
As a real example of this, when most of the population smoked cigarettes, the proportion of heritability of lung cancer attributable to genetics was low. As smoking prevalence drops, the proportion of heritability due to genetics rises.
Yes, this. I find heritability percentages very unintuitive, especially since they don't max out at 100%. I'd be inclined to give the NHS (and WebMD, which is similarly woolly about the causes and just says "*can* run in families", https://www.webmd.com/schizophrenia/mental-health-schizophrenia) the benefit of the doubt.
Is it really a stretch for the NHS to take as a context conditions in the UK at the time of writing the article? To say it's fair enough to be vague when stating facts if that fact varies by time and place would justify saying "it's hard to say whether there are between 65m and 75m people in the UK today, and the population has varied over history, and today varies by country".
Do you really believe that they couldn't easily provide the reader with considerably more information by writing something like "mostly genetic, but physical, psychological and environmental factors also make some contribution"?
I couldn't imagine writing something so unnecessarily vague unless I couldn't be bothered to check what the truth was, or I didn't want to admit what the truth was.
I'm not sure if your numbers are right. If the TFR is 1.0, then each parent has (on average) 1 child, who have on average 0.5 children. So each grandparent has on average 0.5 grandchildren. If the TFR is 1.4, then each parent has (on average) 1.4 children, who have on average 1.4*0.7 = 0.98 children. So 100 randomly selected grandparents have 98 children. Your numbers work if you mean 50 grandparent couples, but if you mean 100 unrelated grandparents, I think you are out by a factor of 2. So maybe it's that we mean different things, but it's not as bleak as I understood from my reading of your numbers!
I don't follow your reasoning. You seem to be double-counting the children in the first generation, but only single-counting the ones in the second.
Either approach could make sense for different purposes, but not mixing them.
I think the approach Edrith is using here is more usual and makes sense in this context. Although I have two children, they're the same two children my husband has, so I've only replaced myself with 2*0.5 = 1 person, not 2.
If the TFR is 1, then for every 100 adults in generation N, there will only be 50 children in generation N+1. This multiplies up across the whole population. If you decide to look at a group of 100 unrelated people and say they actually have 100 children, then you also have to say that the group of their 100 partners has 0 children (because you already counted those children to the first partners), so overall there's only 100 children from 200 adults.
So the number we're really interested in here is how many people are there in Gen(n+2) for every 100 people in Gen(n). I'm confident my numbers are correct in terms of describing this
I find the 'grandchildren' framing a useful way of communicating this simply (can't claim credit as have seen it used elsewhere) as a lot of people find TFRs non-intuitive.
I framed it as 'Every X Taiwanese can expect Y grandchildren between them' to try to make clear we were talking about populations, not counting how many grandchildren a specific person had, to avoid the double-counting you refer to. I'd welcome any suggestions on reframing that keep the simplicity but avoid ambiguity.
P.S. I think Rachael is right in that in your example you've double-counted the children in the first generation and single-counted in the second. In the simple case where TFR = 1 because everyone has precisely 1 child, everyone of the relevant generation is a grandparent and all of them have precisely 1 grandchild, not 0.5.
I think we are reaching understanding here, if not consensus. There is a natural double counting of children at the next generation, as you count not only your children, but also your spouse's children. If I say: you have 2 children, that is correct. If I say: your spouse has 2 children, that is correct. But together, you have 2 children, not 4 children.
But there is a natural single counting at each subsequent generation, you count only your children's children.
The simple phrasing is that a TFR of 1 means that for every 100 people of the current generation, there will be 50 in the next generation. But if you use the parenting phrasing, every 100 fathers in the current generation will have on average 100 children. And every 100 mothers in the current generation will have on average 100 children. So it seems reasonable to say that every 100 parents in the current generation will have on average 100 children. Each child is counted twice - but that is how we count children! They belong to both the father and the mother.
My assertation is that your numbers are correct for describing the numbers of members of each generation, but that they are incorrect for the way in which I have read and understood the statement. I think my way of reading the statement is a natural one, and yours is convoluted. For me, at best it's an ambiguous phrasing - although granted, a more emotive one.
> But there is a natural single counting at each subsequent generation, you count only your children's children.
Actually, scratch that. You are right - if I'm double counting at one generation, then I should be double counting at all generations. TFR of 1 means that on average, every person will have on average 1 child, 1 grandchild, 1 great-grandchild, and so on ever more. But nevertheless, the population is shrinking as each of those children is double-counted, each grandchild is quadruple-counted, and so on.
It's definitely helpful to know that you read it a particular way!
The grandchildren phrasing is definitely emotive, but it also really clearly conveys the time period, which is why I like it. Some people have different views of what a generation is (and e.g. Gen X, Millennial, etc. are only 15 years long).
I think an unambiguous phrasing that keeps grandchildren is, 'for every 100 Koreans today, their will only be 11 people in their grandchildren's generation.'
It won't solve the overall fertility replacement crisis, but I have a policy that would get you more of the people you most want to have.
Make having two of your own children over the age of five living with you a prerequisite for enrolment at universities. Three children, ditto, for grad programs. The carrot: make university free for those accepted. All costs, including for the children.
What's that? Overton Window? Yeah, heard of it. It's a long way away from here, though. Never seen it. I heard it's drifting this way, though. Due to get here in a hundred years.
This would imho never hold.
However, one could conceivably think of other benefits that directly help young parents. Why not give them the first right to certain new (bigger) apartments when they have one child more? Why not either pay them directly more and for longer, or lower social security and tax contributions massively for them as long as their kids are young? Why not tie the value of your old-age pension (at least partly) to the number of kids you raised? And so on.
These are all things that are actually very directly connected with families and raising kids and so far we've always shied away of also reflecting that in our societies. Maybe we ought to start to.
... never hold. You might want to read about the Overton Window sometime.
Those other things have been tried from time to time, although not all of them at once, admittedly. It might be different this time, you never know.
I'm aware of the Overton window and of course you can try to shift it.
The options im proposing are also pretty radical and haven't been tried yet to a full extent. A €200 monthly bonus is a far cry from a €2,000 tax credit per month. And so on.