"Comfortable retirement" is a luxury of the recent past. It wasn't a concept for most of human history and will stop being one for most people fairly soon.
If anything, for most of human history, having someone to take care of you when you're old has been a primary incentive to have kids.
I think that societies should return to supporting this approach to life (but through valuing an individual's contribution, not sanctions). Growing older will always come with changes in one's abilities (not always to the worse) and personal priorities. This should be embraced and encouraged basically up to the point of death. I.e. my village has an organization called "Rentnerbande" (="gang of pensioners") where older guys help local schools, kindergartens and people with beautification and handicraft stuff for free.
We could be a lot less humans on earth, it would be amazing for the environment, and I think we'd be as happy.
The only downside I see is economic (in the sense that everything is built with the expectation of growth). But it is to me an economic problem, and not a reproduction problem.
Because when people are happy they fuck on impetuous and fucking on impetuous generates children (modulo vasectomy and morning after pill)
It’s not about the outcome , it’s about the happiness on the way there, whatever outcome it might be.
Also when people are happy they wind up perishing by fucking around in the real world due to excessive confidence doing dangerous activities such as drinking and driving, jetski accidents, drug overdoses etc
You have to substitute these people somehow
I was quite amused that in your comment you explicitly talk about expanding your lifestyle to have another child: "the need for a larger car and possibly larger house".
Poor people have more children than well off people until you hit top >1% incomes. Economics is not the thing stopping people from having kids, reduction in lifestyle is.
Technically you're somewhat correct, because it sucks to have kids when you know they'll be raised by an economically poorer you.
And as most of the people don't see themselves as economically stable given the socio-economic conditions that have been in place for the last 15-20 years, that means that many people give up having kids because of said economic reasons (so, you're also incorrect, because economics is indeed stopping people from having kids), saying something like this: "I'm already only scrapping by as it is, bringing a kid into the equation will only make things worse for me and my spouse and definitely for the kid".
Not saying that everyone thinks and acts like this, because otherwise no-one would have had children by now, but it's a strong part of the population I would say.
But as the OP says, this is almost backwards. The poorest in America are continuing to have children; their lifestyle isn't encumbered by a family.
Meanwhile, it's the young professionals, who sometimes have a skewed view of what it means to be "poor", who aren't starting families because they don't want to give up aspects of their lifestyle. Again, not a judgment, just observing.
This is a cultural thing. My wife and I ended up with a child at a fairly advanced age. We moved to a rural area about 5 or 6 years ago. Now that our child is of the age to play sports and other activities, we are socializing with other parents. They are sometimes half our age, married with families in their early 20s. These people are what would generally be considered "lower-middle class". And yet most of them have everything they need. There's no expectation that you're going to be a globe-trotting nomad, or live in a 5000 sqft house here. Raising a family is a priority.
I don't think is a skewed view when you don't own a house/apartment, and many of the young professionals from around the world, not only from America, are now exactly in that position.
Honestly glad that it worked out for you moving to the rural area, where I suppose housing is way cheaper, but that option is not on the cards for a lot of younger people out there.
And those kids most often have all sorts of problems when they grow up. Sure, my poor as fuck mom could raise us, and technically keep some food in our mouths, but the stress of doing so while having an anxiety disorder that the back asswards rural community we lived in didn't even know existed until 2010 basically broke her. Thankfully we were predisposed to intelligence by genetics, and a strong family value of education, so the kids all "made it", by varying degrees.
Each and every one of us is in therapy, and on multiple medications. How much does that cost society over a lifetime? How much would it have cost society to just give my mom a little help to raise us instead? Helping poor families not drive themselves crazy struggling to do the basic things of being alive has a huge potential upside, and it's abhorrent that we don't do it because some people think they don't DESERVE help.
"I'm barely scraping by", says the person with an above average income, living in an expensive city, frequently going out, going on multiple vacations per year, buying luxury items, etc.
People who are actually scraping by do not talk about needing to buy a bigger house if they have more kids, because they literally cannot afford that.
https://twitter.com/kitten_beloved/status/166761594887723417...
What do you consider "quite well"? Does your car have a backseat? Does your home have more than one bedroom? If so, you don't need larger of either.
Yes, there are some sacrifices to having a family. Nothing in life is free. The problem is that it sounds like you don't want to your lifestyle hindered by a child. That's fine, but saying you "can't" is untrue. People much poorer than you are doing it all around the world.
But that's not really a problem. The world has plenty of children. If you visit the border of Mexico you can probably snag a handful. Given their state of poverty they won't even mind.
So to the original question. What does it mean for a birthrate to be "too low". Too low for what? Sustaining some level of GDP output? Propping up Wal-marts bottom line with fresh souls to work the checkout counter?
By what metric? Economics?
Economics, ironically, is the reason I don't have more kids. My family is doing, what I would consider, "quite well", but we'd still be pretty fucked with one more mouth to feed, the need for a larger car and possibly larger house.
I truly don't know how people that aren't that far below us on the resources / income scale have any hope of comfortable retirement prior to actual death.