In the U. S., and in most other developed countries, decisions about purchasing producing, and financing housing and housing services have not been left to the unrestricted market decisions of individuals or other private decision making units. With few exceptions, governments have adopted national housing policies to modify the decisions that would be reached in the marketplace. The legislated U . S. goal, "a decent home and a suitable living environment for every American family," [report on National Housing Goals, 16, p. 1] is to be achieved by constructing or rehabilitating 6 million housing units by 1978.