ABSTRACT
Imagine the near-impossible task of walking the length and width of huge urban regions such as those of São Paolo, Mexico City, Delhi, Karachi, or Jakarta. Much of what you would see would not fit easily into the usual images or understanding of built environments and social compositions. Certainly there are large areas of the poor, the rich, and the middle class. But there are also extensive areas where the mixtures are so intense that it is not easy to make definitive attributions. These are the domains of nurses, teachers, factory and service workers, police, storekeepers, technicians, drivers, and those who adamantly refuse to be officially employed.
