Over the past several decades, researchers, politicians, and corporate leaders have focused reform efforts on the size of educational contexts. Hundreds of billions of public and private dollars have been invested to reduce the size and scope of both classrooms and schools (Lee & Ready, 2007). Unlike many education reforms, these downsizing plans have attracted support from virtually every quarter, and a united front of stakeholders has coalesced behind the notion that "smaller is better." Efforts to reduce elementary-school class sizes have garnered particularly strong popular and political support. Indeed, the American public feels that creating smaller class sizes is the most effective way to recruit and retain highly qualified teachers (Rose & Gallup, 2007). Thirty-two states now fund either voluntary or mandated class-size reduction programs, with California and Florida together investing almost $20 billion to reduce class sizes. The author organizes this interpretive and analytic review into three main sections, each of which focuses on the potential links between elementary-school class size and educational equity. In the first section he discusses findings from the three distinct analytic approaches employed in class-size research: randomized experiments, quasi-and nonexperiments, and meta-analyses. The second section moves from research to practice, and describes the large-scale class-size reduction programs currently operating in California and Florida, and what individuals have learned from these programs in relation to educational equity. The third section addresses the financial and opportunity costs associated with universal class-size reduction policies, particularly how these costs influence the educational experiences of low-income and minority children. (Contains 14 notes.)