This is misleading. Birth rates globally are still above replacement level. Even if they weren't, immigration still provides opportunities for people to move from areas of higher relative birth rate to areas of lower relative rate, should they choose to.
it's not really misleading at all. Places like Vietnam, the Philippines, Thailand, India, Bangladesh, and Malaysia all had birth rates below replacement in 2021.
Sure, you can still find nice big numbers in places like Niger in sub-saharan Africa, but even they are starting a sharp decline. And they are starting with a low base. Their entire national population is only the size of the greater NYC area.
What you're describing is tragedy of the commons. No negative consequences to not having children, but big negative disproportional cost to the parents raising them. With disproportionately privatized losses and socialized gains.
People often say you shouldn't have kids for your own retirement. In the ultimately hypocrisy, they often mean kids will be for everybody's retirement (when they're forced to pay social security taxes as adults).
The economic incentive is to let others have kids and shoulder disproportionately the costs, while you can free ride and "not have negative consequences." Immigration doesn't solve this problem at the system level as removing children from foreign tax pool into our domestic pool shifts benefits from one elderly person to another.
> Should an individual opting not to have children be expected to have negative consequences in old age? IMHO, no.
The question is then who will care for these people when they get old? Other people's children? So other people should have children, put the effort to raise and educate them for your benefit? This is a very egotistic view.
I would argue that expecting your children to care for you is actually far more egotistic than merely expecting a social safety net for all people to exist.
I did not say that in any means, shape or form. I said that all people need someone to help them when they are old, so all people have some responsibility these "someone". The "someone" are children of people, so society needs people to have children that will become adults and be part of society; all people, if possible (medical conditions are usually the accepted exception).
At a societal level, is an imbalanced population pyramid a problem? Yes, and many countries are solving this by opening up immigration options.
Should an individual opting not to have children be expected to have negative consequences in old age? IMHO, no.