Over the last decade, accountability reform has been at the forefront of the domestic policy agenda. Although the Obama Administration was critical of some elements of No Child Left Behind (NCLB), its policies endorsed high-stakes testing and expanded the scope of the stakes. With the Race to the Top and an NCLB waiver process, the administration doubled down on using student test results for high stakes purposes, making not only schools but also teachers and principals accountable for student achievement growth. This study addresses methodological challenges for evaluating NCLB by introducing a new quantitative measure for describing states' accountability systems. To create the implementation measure of states' accountability policies from 2003 to 2011, the authors combine a dataset they created of states' accountability policies with information from several federal data sources, including the NAEP and the Common Core of Data (CCD). Their implementation measure is unique in that it depends only on state policies, but not on population characteristics of schools and students within states. The measure allows them to describe quantitatively states' implementation of accountability policies during the NCLB pre-waiver period, to assess how these policies changed over time, and to examine how schools responded to state accountability pressures. The study employs a research design called simulated instrumental variables, which has not been used to study educational reforms but is well suited to uncover links between policy implementation and outcomes. In the preliminary analyses, they used the population of Pennsylvania schools in 2007-2008 to serve as the fixed sample that was "fed" through the AYP calculator. They authors chose Pennsylvania schools because the state department of education provided them with sufficient input information needed for their calculator and included schools with enough variation that reflect changes in state policies across time. Overall it was found that a 1% increase in stringency of Adequate Yearly Progress (AYP) policy led to a 0.07% increase in schools' failure rates. Tables and figures are appended.