Most of the studies I've seen indicate that the isolated nuclear family doesn't work and that with the increase of mobility and the fraying of social networks, modern industrial society becomes more and more punitive towards successfully rearing a family. That's generally what all these studies indicate: "If you want future taxpayers, give their parents a break."IMHO, the studies on happiness and the effects of child rearing in industrialized nations really point to the one real problem, which is how the exclusively nuclear family doesn't work out in the end.
Socioeconomically speaking, our primary issues are related to the "village" being banished from modern society. When you've got grandparents and aunts and uncles, it's a lot easier to raise a kid. Elizabeth Warren has a great book she wrote with her daughter about ten years ago.