Banning the Boston Mechanism in Britain: Effects on School Segregation and Student Achievement
Countries and cities around the world are increasingly relying on centralized assignment systems to assign students to schools, usually choosing one of the two most common algorithms: the Deferred-Acceptance or the Boston mechanism. Yet, the Boston mechanism is often criticized for harming disadvantaged families who are less sophisticated and fail to get access to the best schools. This paper investigates the effect of the national ban of the Boston mechanism in England after many years of coexistence with the Deferred-Acceptance algorithm. We use a Differences-in-differences approach to analyze the effect of the ban on school composition. We start by showing that schools were using the Boston mechanism as a way to cream-skim high-performing students. Then we show that, by preventing schools from cream-skimming students, the ban reduced the share of high-performing students and increased the share of low-performing students and disadvantaged students in these schools.