Value-Added to What? How a Ceiling in the Testing Instrument Influences Value-Added Estimation

The authors thank Andrew Zau and many administrators at San Diego Unified School District, in particular Karen Bachofer and Peter Bell, for helpful conversations and assistance with data issues. We also thank Yixiao Sun, Julie Cullen, Nora Gordon and Dale Ballou for their useful comments and suggestions, and the Spencer Foundation and the National Center for Performance Incentives for research support. The underlying project that provided the data for this study has been funded by a number of organizations including The William and Flora Hewlett Foundation, the Public Policy Institute of California, The Bill and Melinda Gates Foundation, the Atlantic Philanthropies and the Girard Foundation. None of these entities has funded the specific research described here, but we warmly acknowledge their contributions to the work needed to create the database underlying the research. The views expressed herein are those of the author(s) and do not necessarily reflect the views of the National Bureau of Economic Research.