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james_nicoll
Someone appears to have added to the article on Demographic Transition this bit (in October, I think):

In the current century, the past decade as of 2012, most advanced countries have increased fertility. This is completely expected from the viewpoint of evolutionary psychology, with drastic environmental changes causing selection of behavioral traits that increase reproduction.



There is an associated footnote but the
link it goes to is dead. All I can tell from a bit of search is that it began with

13 Oct 2012 – Forecasters say they expect the world's population to reach 10bn by the year 2050 - but could the figure be 36bn?


Did the BBC yank this article from their site?

Also posted at Dreamwidth, where there are comment count unavailable comment(s); comment here or there.

I got to the BBC article without any difficulty. It's long on speculation, and short on numbers.

So as countries get richer their fertility rates fall. But what happens next? Many statisticians assume that advanced nations will remain in periods of low population growth.

But recent evidence suggests they could be wrong.

"Historically, fertility has been falling across Europe," says Professor Jane Falkingham, director of the ESRC Centre for Population Change at Southampton University. "But actually if we look at the most recent period, the last 10 years or so, we see rises in fertility in the most advanced countries."


No citation or numbers provided.

I know there's been some evidence that fertility rises to some degree among the very wealthy, and also that some countries have been able to stem demographic decline by destigmatizing single motherhood and providing lots of social support. So there may be a degree of demographic retransition where an individual is so wealthy on a cash or social support basis that having children becomes a relatively negligible cost and therefore it's just a matter of personal taste as to how many.

It's not usually a high level of growth, though, just above replacement rate.

Weird. It was not working earlier...

There has been some talk of a fertility J-curve, with fertility rising as HDIs increase.

http://www.flickr.com/photos/rfmcdonald/6154239901/

Many countries have seen sustained fertility increases over the past decade, for a variety of reasons including relatively higher immigrant fertility and the recuperation of fertility by women later in their reproductive careers. (i.e. women having in their 30s the children that they didn't have in their 20s.)

Is this necessarily the case? I'm agnostic about the idea. Certainly it's not universal. In the case of West Germany, despite steadily rising HDI since the early 1980s, with the exception of a minor bump upwards in the late 1980s and a sharp drop afterwards lasting to the mid-1990s, TFRs have been consistently below 1.4. Italy has seen a bump upwards in fertility in the second half of the decade just passed, but TFRs are still lower than they were in the early 1980s. Et cetera.

Maybe a case can be made that human development broadly defined to include progress in gender equity, i.e. structuring societies so as to allow women to do a better job of combining family life and work life instead of forcing them to choose and pushing a goodly share of women out of the family track, is related to fertility.

Bear in mind that I will be very surprised if IVF doesn't become remarkably cheaper within the next 10 years; currently the functionally stillborn nature of the agricultural cloning industry has slowed down a lot of research that would have driven IVF a lot closer to the platonic "one egg = at least one baby" standard as well as other little biology things that would drive costs of the procedures down a fuck ton.

And remember that the most important, as far as the average person is concerned, discovery this year was not the Higgs Boson but the fact that ovaries do not have a physical limit to how many eggs they can produce.

Give it 10 years and you'll have the first octogenarian mother giving birth to a child that started out as one of the first oocytes to be coaxed out of the octogenarians ovaries in 40 years, was fertilised in the lab and then implanted back into the octogenarian's fully operation battle station uterus. (oh and more importantly, the first anti-menopause treatments that don't fuck with old lady's bone density, but that's not relevant to this discussion)

A sudden wave of retiree mothers could wash away some of the foundations of the demographic transition in the MEDCs, especially in florida, god help us all.

Assuming said octogenarian moms also have enough energy to carry a pregnancy to term, give birth, and raise said baby...

1) While IVF is expensive -- typically around $12 - $15k per go -- its cost is tiny compared to the cost of actually carrying and raising a child. You could make IVF free and gross fertility rates would barely budge.

2) An octogenarian mother is a deeply bad idea, for reasons that hardly need spelling out. See, e.g., the very sad case of Rajo Devi Lohan.

I'm going to go out on a limb and guess that you don't have kids?


Doug M.

I confidently predict that there isn't going to be a statistically-significant number of octogenarian mothers before the average lifespan rises enough that none of them are retirees.


Interesting graph, but

(Anonymous)

2012-12-29 03:39 pm (UTC)

eyeballing the latest TFRs, I have trouble seeing all these countries with high HDIs but >2.2 TFRs. Running down the list and looking at the countries between 2.2 and 3? I see Israel, Argentina, Malaysia, a few of the Gulf States and maybe South Africa. So, I'd be interested to know what countries those little triangles stand for.


The idea of a fertility J-curve isn't inherently nuts, but at this point it would have to be a hell of a curve to bring Spain, German, Italy, Japan or the Ukraine back -- all countries that have been far below replacement for over a generation now. Of course, it wouldn't need to; if it were just to affect China, India, or a few of the more populous second-tier countries, it would be enough to reverse the decline in world population growth. But there's no sign of that happening right now.


Doug M.

But the thing that needed citation wasn't evolutionary psychology but the assertion that fertility rates have increased in developed coutnries since 2000 (or 2002, or 2010, I am not sure which they mean -- "In the current century, the past decade as of 2012." (it could be anything really)

It's counter to what I've heard in the recent past, and would be really interesting if it were true. It's also counter to what I've seen anecdotally with the child-bearing-age people I know, though we all know what an anecdote's good for (it's good for forming a question so you can run and get good statistic).

This isn't exactly what we're looking for, I don't think.

It gives a slight rise in estimated 2012 fertility over actual 2005-2010 for the US, and a slight rise in 2010 over 2005-2010 followed by a bigger drop for the UK, Sweden, Norway, and a slight drop from 2005 to 2010 followed by an estimated return for Germany (settling at 1.41!, Finland, )and Lithuania (at 1.27!), and a steady rise for France (almost all the way to 2!)and Japan (up to 1.39!), and a steady drop for China.

None of the developed countries I looked at were at or above replacement values except the US. (which is barely above replacement level, and considering the steady erosion of living conditions and safety net here, it may not be above replacement level for long -- replacement level is supposed to be an average of 2.3 or so worldwide, and 2.1 for the developed countries, and much higher where child mortality is high, or where there is famine or war or any other factor that would impact the survival of the granddaughter).

If these figures for total fertility rate are at all related to the claim in the article, they don't seem to support it unless you choose like four countries to stand for all of them. Honestly, all the numbers looked like noise to me -- it looked like these countries were all holding steady, at replacement levels or well below.

edited in a desperate attempt to stop leaving typoes all over the landscape like a fool. Probably futile . . .

Edited at 2012-12-28 11:03 pm (UTC)

They didn't even back up the evopsych thing though, here's the bit from the beeb:
"Demographers used to be the lucky ones because we thought it was easy to forecast population change. I think that's no longer true. It's no longer true at the global level because recent fertility trends [indicating an increase in fertility rates of non-immigrants] are showing that the future is much more uncertain than we thought. There may be a complete change in the ranking of fertility levels in the world."

Evolutionary biologists might not be surprised by this. The idea that as we get richer we have fewer children is, from their perspective, very odd. Normally natural selection produces individuals who are good at converting their resources into lots of fertile descendants.

It's a demographic paradox that in the past few centuries, developing societies haven't been filled by families who raise as many kids as they can possibly afford.


(ignoring the issue that their use of "natural selection" is not correct) The article is asserting that the evopsych friendly result would be one where the population of MEDCs literally impoverishes themselves through childcare costs as a result of having such a high fertility rate, which the minor upward bounce in fertility rates isn't and which means that existing demographic trends are therefore paradoxical given evopsych, not that evopsych actually predicts the upward bounce or anything.

The rest of your comment: Bear in mind of course that due to the difference in populaton levels in India and China and indonesia compared to pretty much the entire world the fertility rates in those countries are going to be the main driving force for global demographic trends for the next 50 years or so, so a layman can basically ignore the demographics of europe or north america unless something really weird happens, because they're only really interesting as possible indicator models for future trends in India, China or Indonesia if a layman wants to know about future global population trends as they move into and through the 5th demographic stage, not in and of themselves (simply because at this point they seem to have hit an equilibrium that they're not budging from)

I agree that population levels in India and China make their fertility trends largely the driving force of future world population. Indonesia, not so much. Indonesia is smaller than the US, and not much larger than Brazil, Pakistan, Nigeria, and Bangladesh.

Yes it's important for future population estimates whether Indonesia stays near replacement level, but more important is whether some of the other second tier large countries with high birthrates continue their fertility or transition to replacement level. So Nigeria with 5+, Pakistan approximately 3 1/2, and Ethiopia with 5+ may be more vital to estimate future population.

Jim Lovejoy

Ignore the indonesia stuff, I remembered their population wrong.

Nigeria with 5+, Pakistan approximately 3 1/2, and Ethiopia with 5+

Death rates are likely going to be a confounding issue with Pakistan: the increasingly inevitable 9001st afghan civil war is probably going to lead to the further pakistanisation of the taliban in the tribal regions and with that is going to come Pakistani Crack Epidemic 2: bigger, worser, which is going fuck with demographics in hard to predict ways in the near future.

Ethiopia and Nigeria are gonna work best as useful heuristics for the rest of the LEDCs as far as the demographic transition is concerned imho.

If India and China afre driving population growth, we aren't looking at growth at all. China's well below replacement level at 1.6 in 2010, and given the poverty that most of India still lives in, they are not above replacement level either at 2.6 in 2010. Indonesia's at 2.1 by the chart I linked to, which is probably a bit under replacement for them.

Remember, fertility is just the babies they give birth to, not the people who reach maturity and go on to have more babies. So those numbers for Pakistan and Ethiopia may not actually represent growth at all, given the persistance of war and famine in both those places. As for Nigeria, what that birth rate means depends on who's having those babies, as disparities in living conditions are pretty stark there depending on where in Nigeria you live.


Higher death rates and--in India and China--gender bias at birth do raise the platform necessary to support replacement level fertility.

Ethiopia

(Anonymous)

2012-12-29 03:49 pm (UTC)

Hasn't had a major famine in ~15 years. The current Ethiopian government is not exactly a liberal beacon of human rights, but it has proven pretty competent at the basic task of making sure its people get fed.

Ethiopia also hasn't had a major war in that long. Several little wars, but they've all been fought largely outside Ethiopia's borders.

(A minor point, but I've spent time in Ethiopia.)


Doug M.


Yeah, I should have said "and in Ethiopa, where things are looking up, they're still feeling the pressure from their neighbors." Notice also that their fertility rate is lower than most of Africa.

Thanks for catching that (I don't think misrepresenting the conditions of a country is that minor, so, again, thanks)

I'm not making an argument as to whether the countries I looked at indicate anything for world population trends. I just looked at a handful of countries to see whether they supported the claim that "developed countries are experiencing an increase in fertility."

The "demographic paradox" is a stupid assertion too. There's nothing paradoxical about people concentrating their resources on a smaller number of children when they have reasonable assurance that the children are going to live long enough to benefit from the investment.


The link seems fine now, but it actually starts (possibly edited subsequently) "Forecasters expect the world's population to reach 10bn by the year 2050 - but could the figure be a lot, lot higher?"

It cites this document: http://www.un.org/esa/population/publications/longrange2/WorldPop2300final.pdf

which mentions 36.4bn all right, but as an upper bound on what population might reach by 2300, not 2050; their predictions for 2050 were 7.4 to 10.6bn. I think whoever wrote the BBC article might have completely misunderstood the UN document.

the 36bn is of course from the UN's highest possible fertility rate projections, the low is 2bn, it gets mentioned at the end of the beeb article thusly:

Dr Pawlizcko at the UNFPA says she doesn't expect it to be very significant. She may well be right. But, then again, neither she nor anyone else can be too sure. Statisticians have a long track record of failing to predict important demographic changes.


[snip]

But forecasting population will always be a highly uncertain science.

In 2004 the UN's department of economic and social affairs tried to guess what the global population could be in 2300. [link is PDF]

It said the population would stabilise at around nine billion by 2050 and then remain at that level for the rest of the period. But that was just its medium estimate. Its high estimate was 36.4bn, and its low estimate just 2.3bn.

In other words, when you look beyond existing generations, anything could happen.


So in other words, beeb says: "experts deny this is actually a trend, but experts might be wrong eh? And they hedged their bets so they can't be trusted, not like you can Trust Auntie Beeb and our unstoppable army of grinning necrononces. Be vigilante citizen, and keep fearing that future."

I honestly can't tell: By "fertility" do they mean the ability to have children, whether they procreate or not, or the choice to have children? Because it seems like the two things are being conflated; that is, it looks like "fertility" in some cases means "the choice to have kids increases based on income" and in other cases "fertility" means "the ability to have kids later in life thanks to medical advances."

Seems like two different issues, but maybe the semantics is tripping me up.

Usually when talking about population trends, "total fertility" means the amount of children the women are actually having, so neither the ability nor the choice, just the actuality. It also doesn't tell you how many living children they produce over their lifetime, just how many they give birth to.

The number to watch out for is how many grandaughters reach maturity, but nobody ever produces that exact number for us to look at.

Ah, gotcha. It would be really interesting to see living children versus how many were born, though I assume one could extrapolate a decent estimate if combining childbirth death rates with fertility rates.

In most of the world, rates of infant mortality are sufficiently low to make a relatively small impact on replacement-level fertility.

http://en.wikipedia.org/wiki/List_of_countries_by_infant_mortality_rate

http://en.wikipedia.org/wiki/Total_fertility_rate#Replacement_rates

"If there were no mortality in the female population until the end of the childbearing years (generally taken as 44 or 49, though some exceptions exist) then the replacement level of TFR would be very close to 2.0 (actually slightly higher because of the excess of boy over girl births in human populations). However, the replacement level is also affected by mortality, asexuality, genetic disorders inhibiting procreation, and by women without the desire to have children. The replacement fertility rate is roughly 2.1 births per woman for most industrialized countries (2.075 in the UK for example), but ranges from 2.5 to 3.3 in developing countries because of higher mortality rates. Taken globally, the total fertility rate at replacement is 2.33 children per woman. At this rate, global population growth would trend towards zero."

I've heard some speculation completely unmotivated by data that the Pill is just another environmental challenge that humanity will evolve around by inventing genetic cultural conservatism.

Which apparently never existed before chemical birth control, which in turn is the only way that ever existed to avoid enormous TFRs. I think it's just a fancier form of "the liberals will abort and gay-sex themselves to oblivion."