The late twentieth century was the age of economic globalization. The first part of the twenty-first century will be the age of the city, the urban age. For the first time in the history of humanity, more than half of the earth's population is living in urban areas. Questions regarding the shape, size, density and distribution of the city have become increasingly complex and politicized, and the impact of the built environment on social inclusion and quality of life are at the forefront of discussions about urban planning. These are the issues that have led to the creation of The Urban Age Project, a network of organizations, individuals and research projects that focus on sustainable development in the world's cities. The project gathered a group of internationally renowned professionals for six conferences held in six international cities New York, Shanghai, London, Mexico City, Johannesburg and Berlin to discuss the future of the contemporary urban environment. The conferences offered a platform from which to discuss how architects, urbanists and politicians should plan infrastructure and development without constraining growth and promote a better social and economic life. This book is the result of the discussions and extensive research produced for these conferences. The research is clearly presented alongside informative texts written by some of the greatest professionals in the field of architecture, urbanism, economics and politics, including Richard Sennett, Saskia Sassens, Rem Koolhaas, Deyan Sudjic and Ricky Burdett, and is richly illustrated with photographs, maps, diagrams and statistics. The book is produced in close collaboration with the London School of Economics to ensure that all the information presented is accurate and reliable, and the accessible design ensures that this book will become the essential reference tool for everyone involved in urban planning and development.