This book offers a novel and up-to-date exploration of the common belief that increasing conventional school resources will increase academic achievement and help close gaps between various advantaged and disadvantaged students. Taking the scholarship around this question, such as James S. Coleman’s 1965 report on the Equality of Educational Opportunity, as a starting point, it brings in an extensive range of contemporary data sources and statistical analysis to offer an updated, robust, and considered review of the issue. Moving beyond these empirical questions, it also explores how these empirical findings have been utilized in “education adequacy” litigation, discussing the evolving law of adequacy cases, while explaining the challenges of introducing complex data and analyses within a litigation framework. Judges typically have little experience with the complexity of modern education data and the analyses required to draw sound inferences. It will thus be of interest to scholars, researchers, and faculty and jurists with expertise or interest in education policy, the economics and sociology of education, and public policy.