In North America the housebuilding industry is ubiquitous and locally autonomous. In Ontario during the 1990s, 81% of urban single-family homes were erected by locally based builders, a proportion that varied with urban isolation. Urban areas may be regarded as the industrial districts of home...

No one has documented the changing geography of low-income settlements in any city in the developing world over the entire postwar period. The most plausible model of this changing geography, first outlined by John F.C. Turner, indicates the existence of a dual concentration of the poor: in...