Designed to reach a wide audience of scholars and policymakers, the Brookings-Wharton Papers on Urban Affairs is an annual series that serves as a forum for cutting-edge, accessible research on urban policy. Contents for this volume include: Editors' Summary Looking Back to Look Forward: Learning from Philadelphia's 350 Years of Urban Development Joseph Gyourko (University of Pennsylvania) Property Tax Limitations and Mobility: Lock-in Effect of California's Proposition 13 Nada Wasi (University of California—San Diego) and Michelle J. White (Brown University) Higher Education Appropriations and Public Universities: Role of Medicaid and the Business Cycle Thomas J. Kane (University of California—Los Angeles), Peter R. Orszag (Brookings Institution), and Emil Apostolov (Brookings Institution) Effects of Urban Rail Transit Expansions: Evidence from Sixteen Cities, 1970-2000 Nathaniel Baum-Snow (University of Chicago) and Matthew E. Kahn (Tufts University) Migration within the United States: Role of Race-Ethnicity William H. Frey (University of Michigan) and Kao-Lee Liaw (McMaster University) Growth of China's Medium-Size Cities J. Vernon Henderson (Brown University)