Sarah Cohodes has co-authored a new working paper for MIT's School Effectiveness and Inequality Initiative:

Can Successful Schools Replicate? Scaling Up Boston’s Charter School Sector - New Findings, School Reform, November 2016

"In a cli­mate of school turn­arounds, char­ter school con­ver­sions, and new school open­ings, an impor­tant ques­tion is whether schools that boost stu­dent out­comes can repro­duce their suc­cess at new cam­puses. The authors 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 repli­cate 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."

Read more here.