In The Class Size Debate, two eminent economists debate the merits of smaller class sizes and the research methods used to measure the efficacy of this education reform measure. Alan Krueger (Princeton University) maintains that smaller class sizes can improve students’ performance and future earnings prospects. He challenges Prof. Hanushek’s widely cited analysis of the class size literature, arguing that it gives disproportionate weight to single studies that include a large number of estimates. An appropriate weighting, he says, would reveal that class size is indeed a determinant of student achievement. Eric Hanushek (Stanford University) counters that Prof. Krueger’s re-analysis achieves results different from his own by emphasizing low-quality estimates. He argues that other policies besides class size reduction, such as improving teacher quality, are more important. Jennifer King Rice (University of Maryland) brings a third-party perspective to the debate. She addresses each author’s arguments and focuses on the policy implications of the class size literature.