[0n34n7]

No. The reproductive bracket has remained fairly constant in the last 100 years - i.e whether people get to 70 or 100, reproduction stops at ~50.

The interesting point here is the concept of “population momentum” which acts like a capacitor that buffers decreasing fertility rates in the short term - yet - “peak child” has been reached.

I think the takeaway here is people who extrapolate global population in 2100 at 15+ Billion have it wrong.

[nn3]

It could be also more females reaching reproductive age. Traditionally a lot of kids died early before they could reach it. This was a traditional limiter on average life time.

[simonh]

>No. The reproductive bracket has remained fairly constant in the last 100 years - i.e whether people get to 70 or 100, reproduction stops at ~50.

You're looking at the wrong thing. It's the life expectancy of the children that matters most, not the life expectancy of adults into old age. The reason the number of women in the reproductive bracket has risen is that more of those births are surviving to child bearing age.

[AstralStorm]

To a point this trend does continue, with developing countries taking up some slack.

We'll see soon if this theory is correct with globally stagnating population or not.

[simonh]

I prefer to say stabilising.

[dsfyu404ed]

How you choose to spin it does nothing to change the very negative economic situation that a non-increasing population would bring.

[simonh]

It's not a matter of spin, it' a matter of reality. At some point we need to move to a sustainable economic model. The alternative is eventual catastrophe. By definition an unsustainable economy, which does not become sustainable, will eventually not be sustained.

I also don't agree the consequences have to be 'very' negative. However that's such a vague and undefined term, it could mean anything. I believe the costs are manageable and that a stable, sustainable economy can be compatible with stable or rising living standards.

[jcadam]

It's all self correcting in the long run, I say.

A non-increasing population leads to economic stagnation (at best). That, coupled with a decline in religiosity leading to a loss of societal cohesion will eventually bring down the whole house of cards that is modern civilization.

Famine, war, etc. follows. And we're back to a less populated world with high infant mortality again. Hard times lead to a return to religiosity and large families.

Hopefully this all happens after I'm gone.

[oblio]

> A non-increasing population leads to economic stagnation (at best).

Kind of like in agriculture, there's "intensive" economic growth and "extensive" economic growth. Intensive being when the same number of people are more productive and extensive being when you have more people.

You can have economic growth with a stable population. Heck, Romania's having economic growth while its population is declining! (a population loss of about 10% in the last 15 years, during which time its economy doubled)

[simonh]

What makes you believe secularism leads to reduced social cohesion? Surely it eliminates a source of friction between religious groups?

[ido]

that sounds like a problem with our economic system more than with our reproductive trends. At a certain point population growth would have had to plateau, it couldn't have continued growing forever.

[em-bee]

so that means the replacement rate of 2.3 should be dropping or has dropped

[ido]

15B+ at 2100 is not the main-stream prediction anyway: https://en.wikipedia.org/wiki/Projections_of_population_grow...