RT Journal Article SR Electronic T1 Are Two Teachers Better Than One? JF Journal of Human Resources JO J Hum Resour FD University of Wisconsin Press SP 0420-10834R3 DO 10.3368/jhr.0420-10834R3 A1 Nathan Jones A1 Marcus A. Winters YR 2022 UL http://jhr.uwpress.org/content/early/2022/01/31/jhr.0420-10834R3.abstract AB 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, is widely endorsed as a strategy to give instructional support to students with disabilities within inclusive environments. We leverage longitudinal administrative data in Massachusetts to provide the first causal estimate for the effect of co-teaching across a large public school system. We find evidence that co-teaching leads to statistically significant test score improvements for both students with and without disabilities. However, the benefits for students with disabilities are much smaller than reported in prior studies.