The Relative Influence of Research on Class Size Policy

Abstract

Social science research suggests that reducing class size has its largest effects on the achievement of minority and inner-city children during the first year of formal schooling.' Despite scholarly disagreements about the implications of specific studies on class size, economists generally agree that targeted class-size policies rest on stronger evidence than untargeted policies. For example, economist Eric Hanushek contends that "surely class-size reductions are beneficial in specific circumstances—for specific groups of students, subject matters, and teachers."^ Similarly, economist Alan Krueger notes that the "effect sizes found in the STAR experiment and much of the literature are greater for minority and disadvantaged students than for other students [and] economic considerations suggest that resources would be optimally allocated if they were targeted toward those who benefit the most from smaller classes."^ However, a number of state legislatures have enacted untargeted and expensive policies to reduce class sizes in all schools, among all subgroups of students, and beyond the early elementary grades. Therefore, the central tension between research and policy in the class-size debate is this: research seems to support targeted class-size policies most strongly, but targeted policies are the exception rather than the norm in the policy arena. As a result, some social scientists have criticized across-the-board class-size reductions as prohibitively expensive and scientifically indefensible.'*