Affordable housing for low-income people, and as housing to which homeless people could return, began to appear in the 19th century. In prior waves of homelessness, a gap between the incomes of the poorest households and the cost of rental housing was never identified as a causal factor for homelessness. Karr (1992) indicates that the quality of affordable housing was quite bad, especially in the 19th and early 20th centuries, but it was available in quantity. The contemporary wave is unique in identifying trends in housing costs (and not simply incomes) as an issue. Karrs analysis cites at least four circumstances that contributed to the scarcity of affordable housing:
- The federal governments promotion of zoning in the early 1920s would henceforth make multifamily housing more difficult to develop. It could be developed only in specifically designated areas and would be segregated from one- and two-family residential areas.
- The preference of the New Deal Federal Housing Administration, created in 1934, for underwriting owner-occupied, single-family property would further tilt development away from lower income and multifamily units.
- National housing acts passed in 1949 and 1954 endorsed the clearance of blighted and slum neighborhoods, which were often to be replaced with commercial rather than residential real estate. The consequence was the loss of more affordable units than would be replaced by government intervention in the affordable housing market with either public housing units or subsidies.
- Karr states there has been no satisfactory U.S. housing policy since the 1950s, and the manifestation of its absence is the worsening maldistribution of housing resources.
Such analyses remind us that the roots of the affordable housing problem go deep and that remedies will require a reckoning with more issues than simple production.