The long-term effects of small classes: A five-year follow-up of the Tennessee class size experiment

Reduction of class size to increase academic achievement is a policy option that is currently of great interest. Although the results of small-scale r andomized experiments and some interpretations of large-scale econometric s tudies point to positive effects of small classes, the evidence has been se en by some scholars as ambiguous. Project STAR in Tennessee, a 4-year, larg e-scale randomized experiment on the effects of class size, provided persua sive evidence that small classes had immediate effects on academic achievem ent. However; it was not clear whether these effects would persist over tim e as the children returned to classes of regular size or would fade, as hav e the effects of most other early education interventions This article repo rts analyses of a 5-year follow-up of the students in that experiment. The analyses described here suggest that class size effects persist for at leas t 5 years and remain large enough to be important for educational policy. T hus small classes in early grades appear to have lasting benefits.