This point gets brought up a lot, but it's focused on individual situations; peers influence kids as much as parents, if not moreso (especially when the single parent works multiple jobs).

If the preponderance of a community doesn't value education enough, or can't at least take the time to act on feedback from teachers about how their kids are doing, then you're just going to end up with a self-fulfilling prophesy of failure. On the one hand, you've got kids being made fun of for "acting white" when they try hard, and parents laying into teachers for daring to criticize their children who are acting out.

Money can't fix any of that, and it matters a whole hell of a lot less than parents who at least put in some effort. My best friend- who I first met in college- grew up in near-abject poverty, raised by a single parent who worked a lot. His parent made sure to drill into him the importance of trying hard in school, and what the other kids he tried to emulate were doing wrong (even to the point of having him join a hockey team instead of a basketball team to break him of living up- or rather down- to stereotypes).