Study after study on graduate degrees in education has shown that they do nothing to boost teacher effectiveness. But maybe the right kind of graduate degree can make a difference. A CALDER paper co-authored by Li Feng and Tim Sass found that special education teachers in Florida with advanced degrees were modestly more effective at teaching mathematics, and significantly more effective at teaching reading—the equivalent, in the case of reading, of the difference between a rookie teacher and one with a couple of years' experience.

Using Florida's unique data system, Feng and Sass were able to tie teacher value-added data to experience, in-service hours, special ed professional development and advanced degrees. They could also examine students who received only general education, only special education or a mix of both. Professional development proved ineffective at raising student achievement. Teachers with advanced degrees, on the other hand, raised scores for students who spent at least some time in special ed classrooms.

What factors might be behind this surprising result in reading? Maybe the extra coursework in Florida's schools of education, which are reputed to champion scientifically based reading instruction, helps teachers master the techniques necessary to remediate the reading difficulties of their special education students. Time spent getting a graduate degree needn't be a waste when it's spent learning the things that matter.