Have them plummet from 5 billion to around 100 million when they struggle to give up the conveniences of bread and circuses they had for so long.
I don't think it's good times creating this problem. If it was, we'd see birth rates spike in times of economic crisis, but we see is the opposite.
The cause seems to be that there is some crisis, usually economical. People put off having kids until things stablise. But either things never stablise, or they keep putting it off and putting it off ...only to find themselves infertile. Literally the genius family from the opening of Idiocracy.
People want kids, but can't have them. Birthgap goes into this. But the short version is the people starting families are having the same number of kids at the same rates they always have. It's that people with 0 kids shot up dramatically, and keeps going.
This is why discussing solutions is a difficult one. So many topics are unpleasant or mean admitting some hated group is right. For example-
Like right now most countries dont have gender specific laws regarding family court both can become primary custody holder, the asset split works both ways regardless who made what during the marriage.
On paper, yes. In practice, not so much. I'm sure the statistics of child support or who gets the kids are somewhere, but I don't have them on hand and I'm too lazy to get them. All I have are stories (both online, and in real life) of fathers getting fucked by family court. eg. Someone I know having to get solicitors involved to get his name off a mortgage for a house he wasn't living in any more.
But even if we say you're 100% correct (you do have a bingo card after all). Let's say that family court bullshit is a myth. That means the perception of bias is enough to make it so some men aren't willing to take the risk of dating or having kids in current year.
I don't have the money to have children. No one's going to miss my contribution to genetics. I think a lot of people feel that way. "I'm poor. Me not having kids won't make a dent in anything". Lots of people feel the world sucks too much to bring kids into it. Or they live in areas where they feel it's unsafe and they have little prospect of affording better.
This is the problem I think. Lots of people don't want kids, which is fine. Lots of people want kids but can't have them for one reason or another. Others want kids and can have them, but keep putting it off until it's too late.
2047 (give or take a few years) is predicted to be when the housing market recovers as that's when enough boomers will have died off to make the housing market normalise again. I won't be surprised if the birthrates recover a few years after that.
The problem of birthrates isn't that the developed world is having too little kids but that the developing world is having WAY too many kids
Well I have good news and bad news. The middle east and africa are already showing the early factors leading to a decline. It's a problem that's hitting the whole planet, it's just developed nations got a head start.