In 2011, the U.S. Department of Education granted states the opportunity to apply for waivers from the core requirements of No Child Left Behind (NCLB). In exchange, states implemented systems of differentiated accountability in which they identified and intervened in their lowest-performing...

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...