That reminded me of an editorial in our local paper about proven ways to improve teaching from a 2007 study, "How the World's Best-Performing School Systems Come Out On Top." One of the authors, Sir Michael Barber, was quoted:
"The high-performing systems are better at ensuring that each student receives the instruction they need to compensate for their home background. ... They ensure that resources and funding are targeted at those students who need them most, not those who need them least."
http://www.kentucky.com/591/story/845399.html