Their problem is it’s damned expensive to live there and the people have enough wealth to live well, but not to live well and have children. So, they chose to live well and be childless. (They keep lots of cats instead.)
Those who do have children tend to invest heavily in just the one so that child will do well. If they had more they couldn’t afford to invest as heavily and the many children would have (in their opinion) a disadvantage competing with the other expensively educated children.
A similar phenomenon is happening in America. Wealthy Americans are having fewer children and sending them to private schools. If they had more children they’d be sending them to the sewer we call public education.
A similar phenomenon is happening in America. Wealthy Americans are having fewer children and sending them to private schools. If they had more children they’d be sending them to the sewer we call public education.