The United States has launched a new experiment designed to improve its schools. The most publicized portion of this is the current federal educational policy to expand school accountability based on measured student test performance. Although many states had already installed accountability systems by 2000, a central campaign theme of George W. Bush was to expand this to all states something that became a reality with the No Child Left Behind Act of 2001 (NCLB). The landmark NCLB codified a developing policy view that standards, testing and accountability were the path to improved performance. This discussion provides evidence on the expected effects of NCLB not only on student performance but also on other potential outcomes.