This project investigates the affordable rental housing market over the three decades from 1985 to 2013. It describes the sources of affordable rental housing, and the dynamic process by which housing units move into, and out of, the affordable rental stock. The ability of lowerincome households to afford decent housing has been one of the central concerns of housing policy in the United States for three-quarters of a century; and housing assistance has long been recognized as part of the social safety net. However, housing assistance has never been an entitlement. Far more households are eligible for federal housing assistance, based on their income and household status, than receive assistance.

As of 2013, there were 18.3 million low-income renter households (defined officially as “very low income,” having incomes less than half the median income of their metropolitan area or rural county, adjusted for household size), of whom 4.5 million were receiving housing assistance through the programs of the U.S. Department of Housing and Urban Development, and about another 0.4 million through the Rural Housing Service of the U.S. Department of Agriculture. This leaves at least 13.4 million very low income households who are housed in the private market.