In this article, the authors tackle the question of whether the No Child Left Behind (NCLB) Act has affected student achievement since its enactment in 2002. They present new research that takes on the challenge of distinguishing the law's effects from the myriad other factors at work over the past eight years. The results suggest that its…

The No Child Left Behind (NCLB) Act compelled states to design school-accountability systems based on annual student assessments. The effect of this Federal legislation on the distribution of student achievement is a highly controversial but centrally important question. This study presents evidence on whether NCLB has influenced student…