Copyright © 2008.The Urban Institute.All rights reserved. Except for short quotes, no part of this report may be reproduced or used in any form or by any means,electronic or mechanical,including photocopying,record- ing, or by information storage or retrieval system, without written permission from the Urban Institute.
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 its funders.The authors thank the Annie E.Casey Foundation for sponsoring the preparation of this primer. Thanks also to Martin Abravanel and Susan Popkin of the Urban Institute, who provided helpful comments and advice. Any errors or omissions are, of course, the responsibility of the authors.