Are Two Teachers Better Than One? The Effect of Co-Teaching on Students with and without Disabilities

Are Two Teachers Better Than One? The Effect of Co-Teaching on Students with and without Disabilities

Today the large majority of students with disabilities (SWDs) spend at least 80% of their instructional time in a general classroom. Co-teaching, in which a general education teacher and special education teacher collaboratively provide instruction to students with and without disabilities in the same classroom, has emerged as a common strategy for addressing the challenges associated with educating students within inclusive environments. Co-teaching is intuitively appealing and has substantial support among policymakers and within the special education literature. And yet, to date we know little about its effects. We leverage longitudinal administrative data in Massachusetts in order to provide the first causal estimate for the effect of co-teaching across a large public school system. The effect of co-teaching differs by subject and grade level. Co-teaching has a marginal positive effect on student math scores. In English language arts (ELA), attending a co-taught classroom has a modest but statistically significant positive effect for SWDs in elementary grades, but a significant modest negative effect for both students with and without disabilities in secondary grades. For both groups, the effect of co-teaching is independent of the impact from increasing the proportion of SWDs in the classroom.