There are several national estimates of homelessness. Many are dated, or based on dated information. For all of the reasons discussed above, none of these estimates is the definitive representation of "how many people are homeless.” The best approximation is from a study done by the National Law Center on Homelessness and Poverty which states that approximately 3.5 million people, 1.35 million of them children, are likely to experience homelessness in a given year (National Law Center on Homelessness and Poverty, 2007).

These numbers, based on findings from the National Law Center on Homelessness and Poverty, Urban Institute and specifically the National Survey of Homeless Assistance Providers, draw their estimates from a study of service providers across the country at two different times of the year in 1996. They found that, on a given night in October, 444,000 people (in 346,000 households) experienced homelessness – which translates to 6.3% of the population of people living in poverty. On a given night in February, 842,000 (in 637,000 households) experienced homelessness – which translates to almost 10% of the population of people living in poverty. Converting these estimates into an annual projection, the numbers that emerge are 2.3 million people (based on the October estimate) and 3.5 million people (based on the February estimate). This translates to approximately 1% of the U.S. population experiencing homelessness each year, 38% (October) to 39% (February) of them being children (Urban Institute 2000).

It is also important to note that this study was based on a national survey of service providers. Since not all people experiencing homelessness utilize service providers, the actual numbers of people experiencing homelessness are likely higher than those found in the study, Thus, we are estimating on the high end of the study’s numbers: 3.5 million people, 39% of which are children (Urban Institute 2000).

There were an estimated 130.4 million housing units in the United States in the third quarter 2008. Approximately 111.7 million housing units were occupied: 75.9 million by owners and 35.8 million by renters. Both the number of owner-occupied housing units and the number of renter-occupied housing units were higher than their respective estimates a year ago. Of the 2.2 million increase in total housing units, 1.4 million were occupied and 737 thousand were vacant units. Of the 737 thousand additional vacant units from last year, there were 41 percent that were for rent or for sale. The number of total vacant housing units, 18.6 million, was higher than the estimated number in third quarter 2007. Of these vacant housing units, 13.8 million were for year-round use and 4.8 million were for seasonal use. Approximately 4.0 million of the year-round vacant units were for rent, 2.2 million were for sale only, and the remaining 7.6 million units were vacant for a variety of other reasons.