for providing valuable feedback at various stages of writing, and thank seminar participants at the University of Washington, the Urban Institute, the University of Texas at Dallas, and the 2009 AEA Conference for their comments, and thanks the North Carolina Education Research Data Center at Duke University, directed by Clara Muschkin, for its part in processing and securing this data resource. A previous version of this paper circulated under the title "Career Concerns Incentives and Teacher Effort." CALDER working papers have not gone through final formal review and should be cited as working papers. They are intended to encourage discussion and suggestions for revision before final publication. The Urban Institute is a nonprofit, nonpartisan policy research and educational organization that examines the social, economic, and governance problems facing the nation. The views expressed are those of the authors and should not be attributed to the Urban Institute, its trustees, or any of the funders and organizations. All errors are those of the authors.