Some sensible solutions sometimes turn out to be counterproductive. A prime example may exist in Washington state, which recently instituted a policy requiring new special education teachers to pursue a second endorsement.

The potential risk exposed by Roddy Theobald, Dan Goldhaber, Natsumi Naito, and Marcy Stein of CALDER is that teachers with dual certification in special ed and another subject are roughly 20 percentage points less likely than teachers with only special ed certification to take a special education position. In any given year, they are also 5 percentage points more likely than special ed-only teachers to transfer to a gen ed classroom—a loss that mounts up fast over a few years, given that special education classrooms lose teachers at a much higher rate than other classrooms (see below).

In short, Washington may have exacerbated the shortage of special ed teachers rather than helped it. 

The implications of this study extend beyond the Evergreen State. NCTQ has often proposed dual certification for those pursuing elementary and secondary endorsements as an avenue to address the special ed teacher shortfall that has persisted for decades. This research provides the first evidence that while that approach would likely grow the ranks, it would do so with notable inefficiencies in hiring and retention.

Importantly, among the CALDER findings was one insight towards reducing those inefficiencies. It was found that when teacher candidates complete their placement in a special ed classroom with a teacher holding special ed certification, they are more likely to become special ed teachers. It is not clear that schools and programs understand the importance of making these clinical experience matches. In the Washington state sample, just over 60 percent of candidates seeking special ed certification were paired with appropriately certified special teachers.