It isn't people can't afford kids; it's a. The opportunity cost of having children is higher in rich countries. (E.g. If you are richer, you can say travel mor

It isn't people can't afford kids; it's a. The opportunity cost of having children is higher in rich countries. (E.g. If you are richer, you can say travel more.. but can't easily if you have kids! Also the income hit from having children is also much higher in rich countries) b. Rich countries generally have higher social expectations for parental involvement. Kids cost more in rich countries because parents actually do more.