Educators and policy makers confront challenging questions of ethics, justice, and equity on a regular basis. Should teachers retain a struggling student if it means she will most certainly drop out? Should an assignment plan favor middle-class families if it means strengthening the school system for all? These everyday dilemmas are both utterly…

Students in the United States change schools often, and frequent changes are associated with poor outcomes along numerous dimensions. These moves occur for many reasons, including both promotional transitions between educational levels and nonpromotional moves. Promotional student mobility is less likely than nonpromotional mobility to suffer from…