The article talks about "growth" as though it has to be absolute growth, but it doesn't; it only needs to be per capita growth. If the population is shrinking, absolute growth can be negative but per capita growth can still be positive (all that's necessary is that the rate of absolute decline of the economy is less than the rate of decline of population). In other words, per capita productivity just needs to increase. Which it has been at least since the industrial revolution.

Only if the 1 person can continue to increase their productivity with nobody else to trade with, which is absurd. Increasing productivity comes from specialization and trade.

So, with a constant population we still achieve economic growth.

That is only true if there is a monopoly on automation, which there generally isn't. In which case the productivity increases go into lower prices, which result in greater demand for whatever is still scarce.

That can be capital owners (e.g. land), but it can also be skilled labor or literally anything else which is in demand and people choose to spend the money on that they had saved from the lower prices driven by automation.

This is especially true for things somewhere between niche and commodity: it's not worth automating something if you're not producing enough of them to justify the capital cost of the automation equipment. It's not worth reusing your rockets if you're only launching like 3 satellites per year (still have to keep the factory open and practiced). This is why Moore's Law has slowed: tech has tapped basically the entire world's population (more than 5 billion people have mobile devices now); there aren't vast new groups of consumers to sell to any more, so the investment in the next step is not worth it like it was before.

In short, more humans actually increases the per-person productivity.

* data mining or AI can analyze data sets better than all the humans you could possibly muster, data sets that can illuminate low volume but high impact decision making (new product need, safety critical alerts, incoming asteroids) * robot surgical devices can perform more consistently (possibly higher efficacy) which is highly valuable even for low volume surgeries * automated cars will be demonstrably safer even if overall demand for transportation declines * demand for more specialized and lifelong education will increase even if the number of students decreases (career changes, working retirements, self-improvement, etc) * automated solutions to climate change remediation (carbon sequestration, planting trees, etc) will likely scale well beyond manual labor options in an aging shrinking population and will be needed generations after the damage levels off * space exploration requires automation even for just a single mission, and even a smaller population will likely continue to explore the solar system

I think imagination and adaptation will manage ok. In fact I would rather see capital deployed to less consumption by volume and more high value consumption. Would you rather eat a farm-to-table organic microgreens salad for dinner, or a bag of Wonder Bread?

There may come a time when we don't NEED a larger population to support increasing specialization, but until then a broader population base is needed to foster growth in technology.

Not to mention that those 'one in a billion' history changing genius happen in larger numbers when we have more billions...

It was doubling every 47 years then. That's slowed down to about every 63 years currently, so the times to reach those levels would now be longer, but his original numbers are still instructive for how fast exponential growth can get away from you. Here they are.

• Suppose we populated the entire Earth to the density of Manhattan at noon on a typical working day, when it is at its highest density. By "entire Earth" that means covering every square meter of the surface, including the oceans, with people.

That would take 585 years.

• Suppose that every single star in our galaxy had 10 habitable planets with the same area as Earth, and that we could trivially expand to them. And suppose that there are another hundred billion galaxies with the same number of habitable planets as ours, that we can also expand to. Surely now we are set for billions of years, right?

Nope. That just takes 4200 years at the growth rate he used (doubling every 47 years).

• OK, suppose we don't limit ourselves to planets. We find some way to tap into hyperspace or something for energy, freeing us to use all the mass in the universe for human bodies. All the stars in all the galaxies converted to humans. Let's multiply the available mass by 100 to account for dust and debris and other interstellar and intergalactic matter.

It takes 6700 years to reach that level.

• He also looks at how long, given a population that consists just of humans and plants for the humans to eat, limited only by the amount of solar energy and the efficiency of photosynthesis, until we are at the limit. That's 624 years.

I've also seen a similar calculation that uses the volume of an average human and the speed of light. I had thought it was in that Asimov essay, but it isn't. That one asks when, if you were to take every human and pack them into the smallest sphere that could them all, would the radius of that sphere have to be increasing faster than the speed of light to accommodate population growth. I don't remember the answer, but I think it was somewhere in the several thousand years range.

There's no amount of even remotely plausible technological hand waving one can do to make a case that we could ever actually achieve any of the above, except maybe the "cover the Earth" one.

To convert the numbers above to other doubling intervals, just multiply by the doubling interval you want to use, and divide by the one Asimov used (47 years).

[1] https://www.amazon.com/Stars-Their-Courses-Isaac-Asimov/dp/0...

The global fertility rate is 2.426, which is barely above the replacement rate. The population continues to grow primarily because the people who have already been born have good life expectancies. The UN forecasts that the population will reach a maximum of 10-12 billion by 2100, driven mainly by increasing life expectancy in the developed world. Key quote:

Two-thirds of the projected growth of the global population through 2050 will be driven by current age structures. It would occur even if childbearing in high-fertility countries today were to fall immediately to around two births per woman over a lifetime.

https://en.wikipedia.org/wiki/Population_momentum

https://population.un.org/wpp/Publications/Files/WPP2019_Hig...

http://www.triumf.info/wiki/pwalden/index.php/Issac_Asimov's...

Also, Al Bartlett's thesis:

"The greatest shortcoming of the human race is our inability to understand the exponential function"

https://www.youtube.com/watch?v=sI1C9DyIi_8

The transcript:

https://www.albartlett.org/presentations/arithmetic_populati...

If we can build enough to handle 1000 times that population, one quadrillion people, that can handle 1000 years of growth.

An upper limit on the number of people we can have without leaving the solar system is about 28 octillion (2.8 x 10^28), obtained by dividing the mass of the sum (1.9891 x 10^30 kg) by the mass of an average human (70 kg).

At the current growth rate, that's 3900 years away.

Indefinite exponential growth can overwhelm pretty much anything.

Well said.

Let's face it. Capitalism doesn't need to exist. What need to exist is the human race. Capitalism might as well be a byproduct of our rapid technological advances comes with industrial revolution.

If we think out of box, this might be as well an outlier of our history. Productivity rarely increases this much and drastically through human history, and guess what, the world is fine.

We might as well approaching the ultimate limit that we are testing the Earth's very capacity under the name of growth.

Maybe acknowledging that technology advances later will slow down (it probably already does), the easy to grab resources are fully utilized, and we might not further optimize our energy efficiency, isn't an abnormal thing in the future.

Capitalism is a tool we devised, now it has probably fulfilled its destiny, at least for that time being. And the focus of global governance should shift from being the economical winner to co-exist peacefully and sustainably in a controlled way.

  ...Capitalism doesn't need to exist. What need to exist is
  the human race. Capitalism might as well be a byproduct of
  our rapid technological advances comes with industrial
  revolution.

  Capitalism is a tool we devised, now it has probably 
  fulfilled its destiny, at least for that time being. And 
  the focus of global governance should shift from being the 
  economical winner to co-exist peacefully and sustainably 
  in a controlled way.

Keep in mind they are just entering the phase when they can expect to greatly benefit from their favorable demographics while those in the West are facing decline.

Do you expect them to willingly come on board this new economic deal, that the West proposes? Do you see no conflict of interests?

A sticking point also seems to be: Are people who are having lots of children the same people who are consuming middle-income+ levels of resources?

Back in the 1970s your typical sci-fi dystopia was an overcrowded world. Personally I'm more afraid of a world with ghost cities inhabited by a handful of elderly people

So we'll hit a replacement problem long before natural selection has time to catch up. The replacement issue has already real implications, this will become much more obvious in the course of the next 30 years.

Any relevant change on the population size the propensity for fertility can have; it will take (three, four, five , ...) generations to manifest.

No it doesn’t. My wife an I both wanted to have large families, even when we were children. How will contraceptives affect people’s basic motivations and life goals?

> Any relevant change on the population size the propensity for fertility can have; it will take (three, four, five , ...) generations to manifest.

Five generations is only 100-150 years. And anyway, we have a precedent for what happens when there is significant population reduction: the Black Death. Life got way better for the vast majority of people who survived that event. So much so that it ended feudalism in most of Europe. The only problem is finding pensions. Oh well. It’s incredibly immoral to yoke our descendants with the responsibility of funding an extended retirement for us.

As for the Black Death, the personal and societal restrictions that result from not wanting to die from casual contact were probably quite a relief to escape and reverse. I don't know enough about history, but I could imagine that kicking off a positive chain reaction. After a cold season, people love to play in the sun.

This part is just speculation on my part, though; you're welcome to continue siding with Thanos.

https://www.sciencedirect.com/science/article/pii/S109051381...

The Black Death is pretty well accepted as a contributor to the end of feudalism. I guess you’re positing that somehow that would be the result of survivors feeling elated at having gotten past the catastrophe (which is a temporary emotion), versus their facing an easier life as a result of 50% of the population dying (an effect which lasts a lifetime). Seems implausible to me.

But also, that the reduction in labor supply lead to vastly improved outcomes for laborers is pretty well attested. Lords of the manor started competing for labor because it was scarce. As a result, laborers were able to transition into owning their own property. It was a big deal. And it has to do with permanently reducing the population to well below the Malthusian limit (the plague periodically re-occurred for centuries, culling the population each time).

Is this entirely a genetic thing or are there also cultural components? I’ve long entertained a crackpot theory that North America will be almost entirely Mormon or Roman Catholic in 200 years, partially for this reason. The only reservation being that secular-humanist culture seems to convert people from more traditional cultures even faster than they reproduce....

Or Muslim, although that's more likely in Europe at this point.

> The only reservation being that secular-humanist culture seems to convert people from more traditional cultures even faster than they reproduce....

Perhaps in a few hundred years secular humanism will be seen a memetic Black Death.

It may not be the case that this is how it will work, but it's not a foregone conclusion that "on average" most people will continue to not want to have kids even in the "first world."

(Don't Mormons for instance have a fertility rate well above replacement despite also having higher than average incomes?)

There is pretty strong evidence that the variance in the number of offspring is about 50% genetic.

The difference between the Black Death and a population decline driven by lower fertility rates is that the Black Death disproportionately claimed the lives of the old and the frail. The result of that (at terrible cost) was an increase in average productivity by removing the people who would otherwise have required assistance, along with a reduction in competition for scarce resources (like food).

A population decline driven by a reduction in the fertility rate effectively does the opposite -- you end up with more elderly people compared to the number of young working people. And we haven't had a meaningful scarcity of food in centuries, so the things that are scarce now are certain types of skilled labor (e.g. doctors), which you can only really source from young people because there aren't a lot of medical school applicants from the population of people 55 and older.

they will in combination with economic incentives. In a world where skilled labour is rewarded and the cost of raising a child is higher and higher, whose going to pay for your large family? When people in developed economies today date, do you think they favour high social status and intelligence or sperm count?

Fertility and some other biological traits have always been positively selected for. Is the world overrun by virile, promiscuous musclemen and women with wide hips?

Fertility is a multifaceted trait; the degree to which a woman is fertile is dependent on a multitude of other traits and characteristics. It seems pretty clear that a desire to have children was not really necessary in the past in order to end up with lots of children. Having children was just something you did, so most couples had children and, consequently, fertility was driven by other traits. Perhaps desire to have sex, ability to earn income, etc. But things have changed. Now it seems pretty clear that the most important factors in fertility are A) whether or not the woman pursues college and a white collar career path, and B) whether or not both parents have an innate drive to have children (those two traits are probably related).

So yes, fertility has always been positively selected for. But the traits that drive fertility have changed as a result of our changing environment. So evolution is selecting for different traits at the moment.