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. Tentative contents include: -Growth of Medium-Size Cities in China Vernon Henderson (Brown University) - The Effects on Driving Patterns, Commuting Times, and Air Quality of New Public Projects to Expand Urban Rail Transit Matthew Kahn (Tufts University) and Nathaniel Baum-Snow (University of Chicago) - State Fiscal Constraints and Higher Education Spending Peter Orszag (Brookings) and Thomas Kane (UCLA) - Looking Back to Look Forward: What Can We Learn from Philadelphia's 350 Year History? Joseph Gyourko (University of Pennsylvania) - The Effect of California's Proposition 13 on Mobility Nada Wasi and Michelle White (University of California, San Diego) -Metropolitan Migration in the U.S.: The Impact of Immigrant Minorities, Blacks, and Seniors William Frey (University of Michigan) and Kao-Lee Liaw (McMaster University)