The United States has a well-established system for reporting on appropriate national and local data concerning the affordability, adequacy and availability of housing. Housing conditions in 44 metropolitan statistical areas are assessed. This annual report, published every year since 1991 is known as the ‘Worst Case Housing Needs Report’. Evidence of critical housing problems facing low-income households is provided annually to the United States Congress, drawing on the biennial American Housing Survey (AHS) funded by the United States Department of Housing and Urban Development (HUD) and the Census Bureau. This provides evidence on the affordability, availability and adequacy of housing and defines worst case housing needs of renters with very low incomes – below 50 per cent of the area median income (AMI) – who do not receive government housing assistance, and who pay more than one-half of their income for rent, live in severely inadequate conditions, or both. The AHS data are used to geographically map worst case needs by income, race and ethnicity, with specific focus on rental housing. The AHS housing data advises the US Congress on the funding of specific HUD housing assistance programmes but does not necessarily lead to the definition of specific supply targets. The primary focus of the United States Congress has been on funding and targeting assistance rather than supply outcomes. This has influenced the level of support for housing vouchers (see chapter II), which allow eligible households to “shop” for fair market apartments.[1]

The AHS data are rigorously analysed by the Federal Department of Housing and Urban Development in the “Worst Case Housing Needs Report”. This provides Congress, all levels of government and relevant stakeholders with information on locally differentiated housing needs. [2] The evidence from these reports underpins government justifications for public expenditure on affordable housing programs, such as investment in Public Housing programs and Housing Vouchers.[3]