Much of the research on how housing assistance impacts households examines only the presence or absence of housing assistance without taking into consideration the kind of assistance received. Hence the second question considers the differential effect of several types of housing assistance programs that HUD offers to the roughly 9.8 million individuals receiving assistance. The research will categorize programs into three main program types:

• Housing Choice Voucher program which enables households to rent private market housing of their choice, with households contributing a proportion of their income and the local public housing agency paying the remainder up to a locally determined payment standard
• Public Housing in which the local Public Housing Authority provides housing out of the available stock of units that it manages, which may vary from single-family homes to large, high-rise apartments
• Multifamily programs which provide subsidies directly to private property owners who set aside a share of their units to be rented at below-market rates for program participants.