In over half of the states, there are no more than three districts that reach average achievement levels in the upper third. (educationnext.org)
The gains are large when compared to other possible policy interventions, such as the effects of attending a school with higher average achievement levels or enrolling in a charter school. (educationnext.org)
Recruiting difficulties have been more severe in schools with the lowest average achievement levels. (educationnext.org)