This may qualify for some as "dog-bites-man", but here's a nice little precis on the link between family structure and educational outcomes. Unsuprisingly, kids in two-parent households do better across the board.
Where I live, there are two public elementary schools nearby. One is fairly diverse but mostly serves reasonably well-off folks with mostly intact families (and children of foreign graduate students). The other has a much larger population of public housing kids, almost entirely black and almost entirely from single-parent families. It's been striking how many of our friends, though thoroughly liberal and deeply committed to public schooling, have already decided that they won't send their kids to the second school if they can't get into the first. Not surprising, but a bit striking.