If two schools compete with each other for students and resources, will this result in stronger student outcomes? Current policy in the US and in many countries seeks to promote choice in schooling. Yet, there is little evidence to support the notion that competition promotes stronger outcomes. While competition should promote an efficient use of resources, there can be a downside to this competition if it results in a greater sorting of students along dimensions that would hurt some student outcomes (e.g., sorting based on ability). This article examines the difficulties researchers face when trying to disentangle a competitive effect and summarizes the current research on this topic. The findings are mixed. Limited evidence is suggestive that competition has a modest positive effect on resource allocation and student performance.