The proposition that competition will spur public schools to perform better is now familiar to most Americans and self-evident to many. It is a compelling idea. While much attention has focused on student performance in charter schools, a distinct and important policy question relates to how increased competition from charter schools affects the effectiveness of traditional public schools. That is, how does charter competition impact the students who are not active choosers? Only recently has research on this question been possible in the United States, as choice options became sufficiently widespread to elicit competitive responses from traditional public schools. In this article, the authors explore what research says about the impact of charter schools on improving outcomes for those who opt to remain in their traditional public schools.