Many programs to help the poor create incentives not to earn too much, which discourages hard work. By contrast, improved schooling raises the incentives to work hard at a career because the range of job choices is so much greater after better schooling. So I have long thought of school reform as an ideal avenue for helping the poor. And since monopolies and near-monopolies tend to perform poorly, I have long been a passionate advocate of school choice. In "School Choice in the Long Run," Adam Ozimek provides a subtle discussion of evidence for the benefits of school choice.
Update: In a related post, Matthew DiCarlo provides a good discussion of why attrition "Student Attrition is a Core Feature of School Choice, Not a Bug."