Today at Vox, Matt Yglesias has a post on what he calls “one of my favorite ideas in public policy,” under the headline, “It’s three times cheaper to give housing to the homeless than to keep them on the streets.” He points to a story last week in the Orlando Sentinel on a new study finding that each homeless person on the streets in Central Florida costs taxpayers about $31,000 a year, versus $10,000 a year to provide a homeless person with housing and a case manager. The region’s homeless commissioner tells the Sentinel the numbers are “stunning,” and Yglesias writes that while it might seem “utopian” and prohibitively expensive to give all homeless people homes, it is, counterintuitively, “cheaper to house the homeless than to let them languish on the streets and deal with the aftermath.”

This is not a new idea: As I reported in my March cover story on rising family homelessness in D.C., the cost to taxpayers of putting up a family at the D.C. General shelter is more than $150 a night, and at a motel is about $140 a night. For that amount of money, the city could house three to four families through the rapid rehousing program or keep that many families in their homes with emergency rental assistance.

The trouble isn’t a philosophical or political barrier to putting homeless families in homes; it’s a lack of homes. Rapid rehousing subsidizes a family’s rent for a limited period of time, before the family pays its own way. As a result, the city won’t place families into rapid rehousing apartments that they won’t eventually be able to afford on their own. And because the supply of affordable housing in D.C. continues to dwindle, the city simply hasn’t been able to locate enough affordable apartments to place D.C.’s homeless families and clear out the backlog of residents at D.C. General, other shelters, and the motels where the city’s been forced to shelter families in the absence of other space. (The alternative would be to provide permanent housing or vouchers to all homeless residents, but the costs really pile up, since residents could be unlikely to ever give up their free rent for life, and new participants would be added each year. That’s exponential-level cost growth. And it still assumes there are places for all the residents to stay.)

This isn’t just a D.C. issue. In Central Florida, there may be enough affordable housing that local governments could realistically place all homeless residents into homes through rapid rehousing or similar programs. But in cities with expensive housing markets, that luxury doesn’t exist. Rising housing costs have led to substantial increases in homelessness after the official end of the recession. In New York between 2010 and 2013, the number of homeless families jumped by 11 percent, according to the Department of Housing and Urban Development’s annual point-in-time count. In Los Angeles, the increase was 21 percent. In San Francisco, it was 29 percent. The list goes on.

The challenge in D.C. isn’t just finding housing; it’s finding shelter space for all the families for whom the city can’t find housing. WAMU has a series out today on the D.C. General shelter, which is riddled with problems but still an aspiration for some homeless families who are struggling to fend for themselves. One woman WAMU spoke with had plenty of concerns about D.C. General, but still prayed for a room there to open up for her family.

“D.C. General would at least be a place where we might not be there all day,” she told the station, “but we could at least come one place and lay our head.”

Photo by Darrow Montgomery