Amster explores the historical and contemporary implications of homelessness as a social and spatial problem, drawing upon academic disciplines and policy concerns ranging from urban geography to legal advocacy. Homeless people find themselves in a struggle to preserve places that are theoretically open to everyone regardless of status. Urban spaces in particular manifest a complex ecology comprised of people, culture, architecture, technology, and the natural environment, expressed through gentrification, redevelopment, and privatization. In this ecology, homeless people are criminalized for performing basic activities such as sitting or sleeping. These trends are evident across the U.S. and internationally, linking local issues with wider forces of globalization.