Margaret T. Hicken is with the Department of Epidemiology, University of Michigan, Ann Arbor. Gilbert Gee is with the Department of Community Health Sciences, University of California, Los Angeles. Jeffrey Morenoff is with the Department of Sociology, University of Michigan. Cathleen Connell and Rachel Snow are with the Department of Health Behavior and Health Education, University of Michigan. Howard Hu is with the Department of Environmental Health Sciences, University of Michigan.