Saskia Sassen is the Robert S. Lynd Professor of Sociology and co-chair of The Committee on Global Thought at Columbia University (www.saskiasassen.com). She is the author of Territory, Authority, Rights: From Medieval to Global Assemblages (2008), A Sociology of Globalization (2007), and The Global City (1991), and editor of Deciphering the Global: Its Spaces, Scales and Subjects (2007). Her books have been translated into 22 languages. She is the editor of the volume on urban sustainability in the new 14-volume Encyclopedia of Life Support Systems (2006), for which she coordinated a network of researchers and activists in 30 countries.