Can schools that boost stu­dent out­comes repro­duce their suc­cess at new cam­pus­es? We study a pol­i­cy reform that allowed effec­tive char­ter schools in Boston, Massachusetts to repli­cate their school mod­els at new loca­tions. Estimates based on ran­dom­ized admis­sion lot­ter­ies show that repli­ca­tion char­ter schools gen­er­ate large achieve­ment gains on par with those pro­duced by their par­ent cam­pus­es. The aver­age effec­tive­ness of Boston’s char­ter mid­dle school sec­tor increased after the reform despite a dou­bling of char­ter mar­ket share. An explo­ration of mech­a­nisms shows that Boston char­ter schools reduce the returns to teacher expe­ri­ence and com­press the dis­tri­b­u­tion of teacher effec­tive­ness, sug­gest­ing the high­ly stan­dard­ized prac­tices in place at char­ter schools may facil­i­tate replicability.

Special edu­ca­tion and English Language Learners expe­ri­ence large achieve­ment gaps and account for a dis­pro­por­tion­ate amount of school spend­ing. Whether and how well char­ter schools serve spe­cial needs stu­dents remains a cen­tral con­tro­ver­sy in the char­ter school debate. I use admis­sions lot­ter­ies from near­ly every char­ter school in Boston to esti­mate the effects of char­ter enroll­ment on spe­cial needs stu­dents’ clas­si­fi­ca­tion and achieve­ment. Charter schools remove spe­cial needs clas­si­fi­ca­tions and move spe­cial edu­ca­tion stu­dents into more inclu­sive class­rooms at a rate over two times high­er than tra­di­tion­al pub­lic schools. Despite this reduc­tion in spe­cial needs ser­vices, char­ters increase spe­cial needs stu­dents’ test scores, like­li­hood of meet­ing a high school grad­u­a­tion require­ment, and like­li­hood of earn­ing a state mer­it schol­ar­ship. Charters ben­e­fit even the most dis­ad­van­taged spe­cial needs stu­dents: those with the low­est test scores and those who receive the most ser­vices at the time of lot­tery. Non-exper­i­men­tal evi­dence sug­gests that the clas­si­fi­ca­tion removal explains at most 26 per­cent of the achieve­ment gains for spe­cial needs stu­dents and has no detri­men­tal effect. The results show that spe­cial needs stu­dents can achieve gains with­out the tra­di­tion­al set of spe­cial needs ser­vices in the char­ter environment.