No surprise, in des moines all schools in the area get the same funding per student. This includes inner city schools, suburbs, and rural schools. Yet there is still a large difference in results with the inner city schools doing worse than the suburbs by far.

Either it is cities elect different people to school boards (seems unlikely but I can't prove it), or family background makes the biggest difference. Many others have pointed out family background as the key, I tentend to believe it.