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 achievement based on an analysis of state-level panel data on student test scores from the National Assessment of Educational Progress (NAEP). The impact of NCLB is identified using a comparative interrupted time series analysis that relies on comparisons of the test-score changes across states that already had school-accountability policies in place prior to NCLB and those that did not. Our results indicate that NCLB generated statistically significant increases in the average math performance of 4th graders (effect size = 0.22 by 2007) as well as improvements at the lower and top percentiles. There is also evidence of improvements in 8th grade math achievement, particularly among traditionally low-achieving groups and at the lower percentiles. However, we find no evidence that NCLB increased reading achievement in either 4th or 8th grade.
We would like to thank Rob Garlick, Elias Walsh, Nathaniel Schwartz and Erica Johnson for their research assistance. We would also like to thank Kerwin Charles, Robert Kaestner, Ioana Marinescu and seminar participants at the Harris School of Public Policy and at the NCLB: Emerging Findings Research Conference for helpful comments. An earlier version of this work was also presented by Jacob as the David N. Kershaw Lecture at the Annual meeting of the Association of Public Policy and Management (November 2008). All errors are our own. The views expressed herein are those of the author(s) and do not necessarily reflect the views of the National Bureau of Economic Research.