Peak Population Projections
dothemath.ucsd.edu
dothemath.ucsd.edu
The rate of decline is important to monitor for the purposes of managing expectations of supply and demand in the markets.
One can say that Japan's economy was still buoyed by global population growth, export growth, etc.
Japan's TFR fell below replacement around 1973, iirc. So we should wait at least till 2070 before making assertions about the severity or otherwise of the issue. In the mean time, it sure looks serious.
Japan has been propping up its economy with debt. It has the highest public debt to GDP ratio in the world. Is that sustainable if interest rates climb? I don't know.
https://www.cambridge.org/core/journals/japanese-journal-of-...
previous discussion: https://news.ycombinator.com/item?id=34486824
I imagine if we were consuming news from India, Egypt or Nigeria it would be a very different story.
On top of incorrect projections, I also think most don't understand the math of how fertility rates affect populations. It's an exponential system, so extreme outcomes are entirely possible with rates that seem 'bad' but not that bad, like e.g. a fertility rate of 1. Such a fertility rate, if shared among an entire population, would result in an exponential 50% decline in your population per 20 years. And alongside that you get social chaos, screwed up age ratios, economic chaos, and more. All on an extremely rapid timeframe.
I think this is a self correcting problem, but it's likely far wiser to fix it before it starts fixing itself.
My fear is the correction will involve rolling back women’s rights.
So consider what this would look do to a nation's population over just a single human lifetime - 80 years. China would go from 1.4 billion -> 0.7 -> 0.35 -> 0.175 -> 0.0875 billion. That's China going from 1.4 billion to 87.5 million, the size of Germany, in a single human lifetime. The US would go from 330 million -> 165 -> 82.5 -> 41.25 -> 20.625, the size of Chile, over the same time frame. And this process doesn't stop, it just keeps going.
You would need to essentially replace your entire population with immigrants. And of course you don't just need massive amounts of warm bodies. You need skilled, educated, sex ratio balanced (which means more women than men due to differing mortality rates - men get themselves killed far more frequently), people who are capable of speaking at least reasonable English. There simply aren't enough people in the world to fulfill this in practical terms. And this is just speaking from a technical point of view in terms of scale of the problem. I'm intentionally avoiding the more controversial social, cultural, and other aspects involved in such a process. It's all just a nonsolution. Immigration can briefly help patch a small-scale problem, but at scale it's like trying to keep a sinking boat afloat with a bucket.
In fact when you look at any typical modern fertility correlation explanation, they all really just fall apart under the slightest of scrutiny. Education/income stuff? Look at Thailand - extremely low education, extremely low income, extremely low fertility - even lower than Japan! So what is the real driving factor? It seems clear that if people believe 'true happiness' is just one 'thing' away, then they are motivated to continue chasing those things. Children don't really have a place in this sort of world - as they simply imperil your ability to pursue that sort of perceived happiness. And governments and companies alike have every motivation in the world to push this 'thing based' worldview, consumerism in other words, because it generates income, increases GDP, and so on.
This is the only fertility correlate that explains literally everything in a clean and consistent fashion. For instance the bell curve of income:fertility (very poor and very rich have far more children than the middle class) can be easily explained - both the very poor and very rich are unable to participate in consumerism. The former because of too little money, the latter because they have too much. Thailand? Yes, it's very poor yet there is also rampant consumerism at all levels, and it's even a place when walking into the most mainstream mall in the capitol you're immediately greeted with a literal lambo dealership. And so on for the countless other issues and counter-examples that contemporary fertility correlates fail to explain.
[1] - https://en.wikipedia.org/wiki/List_of_countries_by_tertiary_...
Don’t they correlate with access women’s rights and access to contraception?
I see a very strong correlation with the ability for a woman to live on her own and/or the ability for a woman to access healthcare that prevents her from having to give birth with fertility rate declines.
There is clearly a mismatch between the near term costs of pregnancy/childbirth/infant rearing and the long term benefits of having kids. Humans are unique in that they are the only species (I think) that can analyze and opt out of the mechanism by which evolution propagates the species.
I also don’t know how representative Russia is because broad availability and use of very effective and “easy” birth control (IUD/pills) took place in more recent decades. And according to Wikipedia, Russia did roll back women’s rights to only allowing abortion at 12 weeks (passed 2011):
> During the 2000s, Russia's steadily falling population (due to both negative birthrates and low life expectancy) became a major source of concern, even forcing the military to curtail conscription due to shortages of young males. On 21 October 2011, the Russian Parliament passed a law restricting abortion to the first 12 weeks of pregnancy, with an exception up to 22 weeks if the pregnancy was the result of rape, and for medical necessity it can be performed at any point during pregnancy.
As for what I was talking about, Russia is not the USSR. Following the collapse of the USSR, Russia (alongside all former Soviet nations) entered into a catastrophic era. Birth rates, income, safety, and basically every other aspect of life plummeted to dangerously low levels during the 90s, which throws off absolutely all data because of something completely unrelated to anything we're discussing.
It takes time for the knowledge and culture about birth control to spread. South America specifically had a lot of Catholic influence which probably prevented many women from choosing or obtaining birth control.
Also, modern birth control like IUDs are just a whole different beast. Whereas there were “accidental” pregnancies in previous generations, there are almost none these days unless you are aiming to become pregnant at some point.
Fair enough about Russia, but the USSR was a long time ago now, and I don’t see any modern society with replacement level birth rates outside of small religious groups or immigrants that still have the momentum of raising traditional families, which evidence says dissipates after the first generation.
https://jamanetwork.com/journals/jama-health-forum/fullartic...
Looking to past, in ancient times philosophy meant something different than today. Essentially everybody was expected, as a part of becoming an adult, to develop their own philosophy of life. Ancient religions offered very little in the way of life philosophy. Pre-Abrahamic religions, such as in Greek or Norse culture, had Gods which took on all human characteristics - maliciousness, greed, sadism, and more. The stories offered were metaphorical in nature, rather than something to guide your life by. So this is the era where you get people inventing everything from the Cult of Pythagoras to Zenoism (stoicism).
But in modern times we, in general, no longer have religion and we no longer have philosophy. So what have people turned to guide them in life? And the answer seems largely to be Product. Eternal happiness is always just one new Product away. And not only have many people turned to Product, but there has been an increasing trend of people denying their own mortality - whether through some sort of singularity event, the 'marvels of medicine' somehow growing exponentially to enable people to live indefinitely, or even some fringe quantum immortality views.
What alternative philosophies are emerging seem to also be death cults in any case - viewing humans as little more than machines, rejecting ones own consciousness, and so on. In all of these philosophies and world views there seems to be very little reason for children. And it just so happens that when one starts to look at things from this perspective, it somehow explains everything literally perfectly. I've yet to find a single compelling exception, while every other explanation for fertility just completely falls to pieces under the slightest of scrutiny.
Canada is a good example, where the anti-immigration narrative has become much louder very quickly. People get nervous/upset when they see their culture or population visibly changing.
Uh, expand?
Short-termism of our leaders will lead to a systemic collapse just like in the Soviet Union.
Immigrants quickly take on the fertility characteristics of the host population, because they are subject to the same pressures and incentives. So immigration has to be perpetual. In the mean time, the source countries' fertility is slowly coming down to and below replacement as well. So it can't last forever.
The only thing that is "solved" meanwhile is keeping wages depressed, which helps businesses. Allowing wages to rise might help improve native fertility.
Edit: I should note that in the last few years Japan has modified its residency laws. As well as getting hundreds of thousands of "technical trainees" (in reality, pretty much enslaved factory workers) from China and Viet Nam, it's also getting hundreds of thousands of caregivers from the Philippines, and, for some reason, Brazil.
So even Japan is accepting immigration these days, albeit very reluctantly.
https://en.wikipedia.org/wiki/Demographics_of_Japan#/media/F...
https://en.wikipedia.org/wiki/Demographics_of_Japan#Foreign_...
I assume this "zeitgeist" is among academics?
'Cuz I fear a common political zeitgeist in some countries is a combination: "Overpopulating-Others, Underpopulating-Us."
I can explain the math, but the result is pretty simple. If we imagine an equilibrium point where everybody has the same fertility rate (the typical case being when the final healthy fertility rate generation dies off - just leaving offspring upon offspring of comparably low fertility rate generations), then at the point your population will start changing by a factor of ~fertility_rate/2 every 20 years. So for Japan, with a current fertility rate of ~1.4, they'll be losing 30% of their population every 20 years, for an annual decline of around 1.5%.
Right now they're only losing about 0.5% per year. So they're still in their glory days relative to what's to come starting around 2060. And that future which they're headed towards is the one most Western economies are also headed towards if we don't fix this problem.
[1] - https://en.wikipedia.org/wiki/File:Japan_Population_Pyramid....
[2] - https://data.worldbank.org/indicator/SP.DYN.TFRT.IN?location...
"You want to force women to be baby-making machines", and more vitriolic rhetoric, and loss of tenure, is what happens when someone raises the issue.
I think of this as one of Iain Banks's "Outside Context Problems", something that our society cannot (allow itself to) understand or even see, so it cannot begin to solve it.
The right wing so far hasn’t provided any solutions.
I have one child. I would prefer to have two, but I can’t afford it. For reference: my income is in the top 2% for my country and the top 5% in the affluent part of the largest city. I literally cannot afford to buy a house big enough for a growing family unless my partner also works full time. That’s nuts.
To have kids you need a large enough house and ample financial security / schools / daycare etc.
Doesn’t make sense to have kids when both parents have to work full time to barely make it.
The solution is to make parenthood high prestige, higher than doctor or lawyer or CEO or rapper or billionaire. Then everyone will want to do it.
A pity that despite a hundred years of marketing we are clueless about how to do that.
There are 'hygiene' actions like getting rid of credentialism, so lowering the perceived-to-be-required investment in each child, and decreasing density (which inversely correlates with number of children independently of other factors, and giving people an optimistic life plan and expectation, and changing marriage/partnering back from being a capstone (something you do once you are established) to being a cornerstone (something you do at the start of adulthood, to build your lives on).
But ultimately it's about the social prestige. Try saying "she's a soccer mom" in tones of awe and respect, out in public, and watch the funny looks you get.
What's your point?
Ostensibly, modern countries have not yet suffered the predicted population crash that might incentivize more aggressive baby bonuses (https://en.wikipedia.org/wiki/Baby_bonus). This has been a thing for awhile (https://www.npr.org/sections/money/2011/11/03/141943008/when...).
It's a likely strategy to be extensively employed in the future, if the trends are realized. It's reasonable to expect there is an economic inflection point, where the program(s) would be successful.
The only economic incentivize I can think of that might work is to remove all old age benefits and require people to depend on descendants, but that is not going to be politically palatable until there is no choice because the system fell apart.
I'm not sure that's been proven. Granted, if you need bodies, they quality of the bodies matters a bit.
> I don’t think that can be incentivized by a cash gift or tax credit.
I guess we can agree to disagree.
I was thinking, "Ha; you don't have enough money to pay first worlders to breed." No carrot is sweeter than independence.
But the stick? Now you might be on to something. It kind of doesn't work out though since you're going to suffer elder abuse at the hands of an Indonesian lady in America even if you have kids; they throw you inside a home. Maybe try taking away contraceptives.
Either way, as for the "but will the kids be raised well", that's already a lost battle.
But all of this is moot. It's false dharma. It's the lamp-lighters' union trying to outlaw bulbs and lower kerosene prices. The future is pod clones. Legacy biology and 25+ years of education suck. Grow genetically engineered adults in pods in state-run facilities. That's the only meta worth striving toward.
Who benefits?
(I think I read about this on the IIASA website.)
Time will tell.
China and India having 2.5 billion if they are subsistence farming is a much faster different thing that China and India with some approximation of western lifestyles.
Demographic decline does seem endemic to urbanization, but urbanization is hand in hand with western consumption rates.
Net economic activity will probably increase in net, but with, uh, bumps.
But of course you are correct. Urbanization is responsible for the largest population migrations and geographic redistributions of the last century. I consider it the major factor in the demographic birth rate declines.
Take a look at the massive population increase especially in some countries in 50 to 100 years, even ones without huge amounts of land..population density has skyrocketed vs historical norms. It is no wonder that eventually this puts pressure on birth rates, and some of the lowest birth rates are found in places with some of the highest population densities.
Cost of living and real estate has risen, and it will be a good thing for this to reverse or slow. And some foolish leaders want to short circuit this natural correction by importing new people to compete with local citizens for real estate and resources. Not smart. It will only depress domestic birth rates further.
In the United States 75% of the population lives on 2.7% of the total land area. And in the last century we figured out how to harness unlimited energy, produce as much clean drinking water as we could ever need, practically unlimited food production, raised the quality of life for the average human a thousand times over, not even getting into the fact that we are on the cusp of cheap, reusable access to space. I would consider the human population unbounded.
Our aquifers are being permanently drained, our most productive regions are rapidly desertifying, our growing seasons are becoming increasingly unstable as the climate shifts, our crops are genetically homogenous and therefore catastrophically susceptible to disease, our rampant use of pesticides is unraveling the food chain, we're 100% reliant on the use of artificial fertilizers which is dependent on functioning global supply chains and fossil fuels, and even if you can grow the food there's no guarantee that you have the logistics network necessary to distribute it before it rots.
Which is all to say, food is far from a solved problem. And there's nothing in space that's going to address that particular need.
To your point of housing: that is the most clear example of a thing that is artificially constrained by policy. The reason there are housing shortages has absolutely nothing to do with resource constraints and everything to do with terrible policy decisions.
The world is... only partially finite. The resources are not finite. Check studies for oil wells that have replenished in China over 100 year periods.
Finite space is a tacit of conventional wisdom. Cities like old and modern Rome would disagree.
Your view is centered particularly in the past.
Can you send me some of whatever you've been imbibing?
However that could have been UK specific data.
*EDIT*: It was global, data comes from the Lancet, which is considered a strong source by many: https://www.thinkglobalhealth.org/article/global-life-expect...
We'll probably have more outliers of wealthy/healthy people living longer, but poor management of broader access to basic health and education may not result in that drastic an increase in overall average results.
So start at the bottom. And say we have exactly 2 twenty year olds. Since there are 2 twenty year olds there must be 4 forty year olds, 8 sixty year olds, and so on. This generalizes to there being a total of (2^n) people of age (20*n). So there are 512 people of age 180. The entire population is 512 + 256 + 128 + ... 1 = 1023. So what happens when this 180 year old generation dies? Your population declines by half. What happens twenty years later when the 256 population group dies? Your population decreases by half. So each generation, you start seeing an exponential halving of your population.
So how long people live doesn't actually matter. All it does is add some noise/delay as you shift from an equilibrium between fertility rates. And once that equilibrium is reached, your population will shift by a factor of fertility_rate/2 every breeding generation (~20) years. This holds true whether people live for 40 years, or 40,000. So with a fertility rate of e.g. 1 your population will exponentially decline by 50% every 20 years, until you go extinct or start having babies.
Lots fewer babies are dying, a good amount of young adults are staying alive, some middle age people are living longer, and a handful of older folks are too.
But once you get to 80, 90, your life expectancy is within a few years of where it would have been 100 years ago.
There’s absolutely no evidence that medical technology has made any impact on the maximum age humans can live.
And any impact it’s had on the raw numbers making it past 100 are utterly dwarfed by the kind of factors affecting global population. Like tiny, tiny percents of the population are in this “ nouveau old”.