My wife (a social worker) believes that the best solution is to put a contraceptive in the water supply and only provide the antidote to those who can demonstrate parenting ability and a loving, stable environment in which to raise the kids.
Having seen the generations of mouthbreathing ne'erdowells infesting two continents, and heard the sickening stories of children brought into the most hopeless, fucked-up 'families', I'm finding it hard to disagree with her.