This book is about the threats to education quality that cannot be explained by lack of resources. It reviews service delivery failures in education: cases where programs and policies increase inputs to education but do not produce effective services where it counts in the classroom. It documents what we know about the extent and costs of such failures. It argues that a root cause of low-quality and inequitable public services is the weak accountability of providers to both their supervisors and clients. The central focus of the book is that countries are increasingly adopting innovative strategies to attack these problems. Drawing on new evidence from 22 rigorous evaluations in 11 countries, this book examines how strategies to strengthen accountability relationships in school systems have affected schooling outcomes. The book provides a succinct review of the rationale and impact evidence for three key lines of reform: (1) policies that use the power of information to strengthen the ability of students and their parents to hold providers accountable for results; (2) policies that promote schools' autonomy to make key decisions and control resources; and (3) teacher incentives reforms that specifically aim at making teachers more accountable for results.