The inflexibility of modern urban planning, which seeks to determine the activities of urban inhabitants and standardise everyday city life, is challenged by the unstoppable organic growth of illegal settlements. In rapidly expanding cities, issues of continuity with local traditions, local conditions and local ways of working are juxtaposed with those of abrupt change due to emergency, reaction to modernity, environmental degradation, global market forces and global technological imperatives to make efforts to control by physical planning redundant as soon as they are enacted. In most third world cities there is little social welfare and almost no attempt at social housing.