We are seeing the same tendency of an increase in single mothers in Denmark too.
And here it is not hard to bring a paternity suit and receive child support, as every midwife can and will advise a single mother to do so, and put her in touch with a social worker.
AND since the 1970's social services pay out the child support to the parent with whom the child is actually living and recoups it from the other parent, so no-one is in the futile position of having the legal right to receive child support, but no means of getting an insolvent, or uncaring, parent of a child to pay up.
Talking to young mothers, whether those in committed relationships or single mothers, I have been startled over the past twenty years by the increasing number who bluntly state, "She/ he is MY child. I make the decisions, and if the child's father doesn't like it, he can lump it."
I am not claiming that all young mothers think like this, but a growing proportion seem to be adopting this outlook, even when the child's father is happy and willing to take his share of the raising of the child.
If this is becoming a dominating tendency, then I can begin to understand the "invisible" fathers. Parenting should be a joint task and a joint pleasure, but can only be so, if both parents see it as a joint venture.
Then there are, more understandably, the women who discover that they are pregnant, either because they took a chance, or because contraception let them down, and who decide against abortion.
Those who know full well that the man in the case has no desire for children, quite rightly and fairly, in my opinion, decide to go it alone.
Some of them may not have told the man that he is the father of their child, others have, but have waived their right to child support, as they feel that their decision to have the baby, conceived as "an accident" is not one they should force upon an unwilling father in a day and age where legal abortion is possible and only frowned upon by a small majority.