An urban planner and lawyer
He is Professor Emeritus of Urban Planning at Columbia University, New York.
He has written extensively on housing, urban development, the history and ethics of planning, racial segregation and globalisation. His most recent publications, jointly written with Ronald van Kempen, are Globalizing Cities: A New Spatial Order? (Blackwell, 1999) and Of States and Cities: The Partitioning of Urban Space (Oxford University Press, 2002).