According to Bain & Company's new national education report, many school systems are investing to develop principals, APs and teacher leaders but there is rarely a plan in place to deploy them effectively within their schools. As a result, principals are overwhelmed and teachers are not getting the support they need to progress.

"All too often we've added the titles, but we haven't really effectively changed the dynamic," said Chris Bierly, the global leader of Bain’s K-12 Education practice. Education is unique in that it does not consistently think about what kind of organizational or leadership model is best for the schools, Bierly said. "I can't stress how important it is to get that right."