Comment by thaumaturgy | Hacker News Reader

Comment by thaumaturgy | Hacker News Reader

I keep being surprised that this is surprising to anyone. This is a commonly-observed pattern in biology; a simple graph called the Gompertz function (https://en.wikipedia.org/wiki/Gompertz_function) is often used to model it.

I guess most folks have always assumed that humans were somehow exempt from the natural laws, maybe because of the much greater degree to which we are able to reshape our environment to suit our needs (sometimes to our long-term detriment).

But so many growth-related things seem to follow a Gompertz function that I think it's likely we just don't yet understand all of the factors when figuring out our own carrying capacity.

I'm really curious whether our asymptotic population limit only applies to our population on one world, or if, were we to eventually become multiplanetary, we'd discover that a whole other planet wouldn't really increase our overall population that much.

I wish I could be around to see the answer to that question.

Unless I'm missing something, the Gompertz function you refer to has an implicit model that the organism's population stabilizes because of Malthusian constraints, a lack of some kind of resource.

But birth rates have been declining in first-world countries for a long time in the absence of this kind of constraint, and the Foreign Affairs article specifically notes that both Malthus and Paul Ehrlich's "Population Bomb" doomsday resource-shortage scenarios didn't come to pass.

The Earth certainly does have some kind of carrying capacity for humans, but that's not the limit that's being it, it's something else.

It's often observed that as societies grow richer, their birthrate plummets. The paradox is that in order to tap into those riches people have to work more, which may be one of the explanations for why the population tends to decline in those countries.

Thus the constraint may just be "time to make babies".

Time and resources to make and support babies is a big constraint.

Most parents want to provide a standard of living to their kids that is better than what they grew up in, which costs significantly more to provide.

Kids didn't always have their own bedrooms or cellphones, and in an agrarian society kids were useful as extra "free" labor. The shift to cities has rewritten the economic calculations potential parents do.

Children used to be a way to support oneself in retirement. The more children you had, the better chance that at least one or two would be around in adulthood to take care of you.

Affluence means you have the means to take care of yourself, so therefore don't need to spend the effort of raising kids for this reason.

In the US, I would say affluence actually allows you to have children, if you want to provide them with life in a good school district and a single family home in a suburb close to burgeoning city. You have to borrow student loans, then work to save for a down payment, then save for childbirth and health expenses. Now you have structural costs of student loan debt repayment, mortgage debt repayment, daycare, property tax, retirement savings debt, and possible vehicle debt repayment. And now you’ve advanced in age, and you can only have 2 kids.

I think western population development has gone sustainable largely due to social advancements re women. Not all parts of the world have yet had that kind of progress, and are still happily multiplying in an unsustainable way. Unless we manage to export this kind of progress, I fear we will not be able to avoid all overpopulation issues. One problem is that costly (in loss of lives) regional wars over resources and the enslavement of women as a means of replenishment for your armies are a circular feedback mechanism. Unless the circle of war and patriarchy is broken, some cultures will probably expand to their malthusian limits.

> the enslavement of women as a means of replenishment for your armies

What society has ever done that?

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

We're they raping in order to replenish their armies? The claim is rather far fetched.

The word "rape" in this context is taken to mean abduction. This is then followed by the integration of the abductees into the abductor's society.

From the article: "At the festival, Romulus gave a signal, at which the Romans grabbed the Sabine women and fought off the Sabine men. The indignant abductees were soon implored by Romulus to accept Roman husbands".

That the second phase may have employed carrots as well as sticks does not detract from the fact that the Romans have thereby managed to expand their reproductive capacities while simultaneously contracting that of the rival Sabines.

Every society that denies women independence from men. I agree this is a sliding scale, but near the extreme end is this staple: Girls belong to the parents until such time as they are married off to a husband, who is then in effect their new owner. I take the liberty to call this slavery.

I was talking about forcing women into the army.

Oh my, that's what you thought I meant with "the enslavement of women as a means of replenishment for your armies"?

I fear that was a misunderstanding, good sir. I didn't mean that women were ever press ganged into the army, but into producing the next generation of recruits. Frankly, I actually lold when I got that just now! =)

> Not all parts of the world have yet had that kind of progress, and are still happily multiplying in an unsustainable way. Unless we manage to export this kind of progress, I fear we will not be able to avoid all overpopulation issues.

This is simply not true. Not even close.

I recommend watching:

https://www.gapminder.org/videos/will-saving-poor-children-l...

or, if you can spend more time,

https://www.gapminder.org/videos/dont-panic-the-facts-about-...

or any of Hans Rosling's TED talks. And you'll find that your statement I quoted above is simply wrong.

I've watched Rosling stuff before. What part of the linked videos do you think are evidence against? I maintain there are a number of countries that still have unsustainable population growth. I wouldn't want to pick any one out. But be my guest and have a look-see at https://en.wikipedia.org/wiki/List_of_countries_by_natural_i...

The population growth is basically a transitional state between high infant mortality / high birthrate to low infant mortality / low birthrate. There's no society in existence that had sustained "high birthrate / low infant mortality".

Play the following graph from 1800 to today:

https://www.gapminder.org/tools/#$state$marker$axis_x$which=...

It's very clear where we're headed and we're actually closer to the stable point, given China and India are already near the birthrate of 2.

> ... are still happily multiplying in an unsustainable way.

See the graph above. This is already not true.

> Unless we manage to export this kind of progress

This has already happened mostly. Africa is the laggard currently but is already rapidly catching up, and it's crystal clear that we'll get there.

I recommend taking the gapminder.org test. I think you'll be surprised how wrong you are.

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