This project would not have been possible without the leadership and support of Eli Broad, Arne Duncan, Steven Hyman, Joel Klein, Thelma Morris-Lindsey, Michelle Rhee, and Lawrence Summers. I am also grateful to our district partners: Jennifer Bell-Ellwanger, Joanna Cannon, Dominique West (NYC); Erin Goldstein, Abigail Smith, Hella Bel Hadj Amor (Washington, DC); Amy Nowell, Asher Karp, John Jablonski (Chicago); and David Vines and Jane Didear (Dallas), for their endless cooperation in collecting the data necessary for this project. I am indebted to my colleagues Josh Angrist, Michael Anderson, Paul Attewell, Roland Benabou, David Card, Raj Chetty, Andrew Foster, Edward Glaeser, Richard Holden, Lawrence Katz, Gary King, Nonie Lesaux, Steven Levitt, John List, Glenn Loury, Franziska Michor, Peter Michor, Richard Murnane, Derek Neal, Ariel Pakes, Eldar Shafir, Andrei Shleifer, Chad Syverson, Petra Todd, Kenneth Wolpin, and Nancy Zimmerman, along with seminar participants at Brown, CIFAR, Harvard (Economics and Applied Statistics), Oxford, and University of Pennsylvania for helpful comments, discussions, advice, and support during this research experiment. The seeds of this project were planted in 2003 in a joint venture between the author, Alexander Gelber, and Richard Freeman in P.S. 70 in the Bronx, NY. Brad Allan, Austin Blackmon, Charles Campbell, Melody Casagrande, Theodore Chang, Vilsa E. Curto, Nancy Cyr, Will Dobbie, Katherine Ellis, Peter Evangelakis, Richard Hagey, Meghan L. Howard, Lindsey Mathews, Kenneth Mirkin, Eric Nadelstern, Aparna Prasad, Gavin Samms, Evan Smith, J¨org Spenkuch, Zachary D. Tanjeloff, David Toniatti, Rucha Vankudre, and Carmita Vaughn provided brilliant research assistance and project management and implementation support. Financial Support from the Broad Foundation, Circle of Service Foundation, District of Columbia Public Schools, Harvard University, Joyce Foundation, Mayor's Fund to Advance New York City, Mills Foundation, Pritzker Foundation, Rauner Foundation, Smith Richardson Foundation, and Steans Foundation is gratefully acknowledged. Many thanks to our bank partners Chase, Sun Trust and Washington Mutual for their support and collaboration on this project. The usual caveat applies. The views expressed herein are those of the author and do not necessarily reflect the views of the National Bureau of Economic Research.