This report summarizes current knowledge about the labor market for teachers and provides policy recommendations to enhance the supply of high-quality teachers. Many schools throughout the country, particularly those with low-income and low-achieving students, have difficulty attracting and retaining high-quality teachers. These schools systematically employ less-experienced teachers with weak educational backgrounds and academic skills. Because teachers are a school's most important resource for raising student achievement, the inequitable distribution of high-quality teachers helps to perpetuate inferior learning opportunities for students in our nation?s highest priority schools. Economics provides a framework for understanding and predicting responses to policy change. Economics considers how individuals make choices given what they value and the constraints they face in terms of monetary resources, time and information. This report provides information on teachers' preferences and constraints. It describes the current teaching force and the systematic sorting of teachers across schools. It asks what factors influence teachers' decisions on whether and where to teach, focusing particularly on wages, working conditions and the location of available jobs. Ultimately, the report focuses on policy approaches for strengthening the teacher workforce, with particular emphasis on recruitment and training. It concludes that in order for reforms to effectively improve teaching for the students most at-risk of failure, policy changes must directly target the most difficult-to-staff schools, providing incentives for teachers to work in these schools.