School admissions reform in chicago and england: Comparing mechanisms by their vulnerability to manipulation

mechanism midstream, citing concerns about its vulnerability to manipulation. Nonetheless, they asked thousands of applicants to re-rank schools in a new mechanism that is also manipulable. This paper introduces a method to compare mechanisms by their vulner-ability to manipulation. Our methodology formalizes how the old mechanism is at least as manipulable as any other plausible mecha-nism, including the new one. A number of similar transitions took place in England after the widely popular Boston mechanism was ruled illegal in 2007. Our approach provides support for these and other recent policy changes. (JEL C78, D82, H75, I21, I28) In the last few years, policymakers at several school districts have sought to simplify strategic aspects of school admissions in their open enrollment or school choice plans. A first change occurred to Boston’s grade K–12 assignment system, known as the Boston mechanism, in place since 1999. Abdulkadiro ̆ glu and Sönmez (2003) show that this mechanism is vulnerable to strategic manipulation, an