The National Law Center on Homelessness & Poverty currently estimates that each year at least 2.5 to 3.5 million Americans sleep in shelters, transitional housing, and public places not meant for human
habitation. At least an additional 7.4 million have lost their own homes and are doubled-up with others due to economic necessity.
But data related to homelessness are far from exact. Part of the difficulty is that there are different definitions of homelessness now in use. For example, the U.S. Department of Housing and Urban
development (HUD) uses a narrow definition largely limited to people living in shelters, in transitional housing and in public places.
The U.S. Department of Education (DoE) uses a broader definition that
includes families who are doubled-up with others due to economic necessity. Another difficulty concerns methodology. HUD reports annual “Point-in-Time” counts of the “unsheltered” homeless population; however, the methodology used to collect those numbers varies by community and is often deeply flawed.2 HUD also reports annual counts of the sheltered population; this number varies with shelter apacity, which depends on variables such as available funding.