Homelessness is the point where numerous other issues intersect. Housing affordability, addiction, mental health problems and availability of social services and jobs are factors that can combine to land a person – or a family – on the streets.

In order to help the homeless, it’s imperative to understand who they are and what factors might have combined to leave the individual or family without shelter. That’s why the city’s annual point-in-time count, which is mandated by the U.S. Department of Housing and Urban Development for any jurisdiction that receives federal funding for homeless services, is so important.

As detailed in today’s page one Times story, “Surveying Alexandria,” homelessness circa 2018 does not neatly fit the stereotype of the chronically homeless, addicted person sleeping on a city grate. Certainly, addiction can still be a factor in homelessness, and given the surge in opioid addiction these past few years, may become more of one. Other types of mental illness can also be factors.

But the job and housing availability factors clearly play crucial roles in homelessness, though with housing, ironically, perhaps not in the way we might assume.

The largest single factor in determining homelessness is arguably the economy and availability of jobs. In 2011, when the country was still slowly shaking off the effects of the Great Recession, the unemployment rate in Virginia stood at 6.3 percent – and a total of 416 people were counted in Alexandria’s point-in-time homeless survey.

In this year’s point-in-time survey conducted in late January, 226 homeless people were counted in Alexandria, and Virginia’s unemployment rate in December 2017 had dropped to 3.7 percent, according the U.S Department of Labor Statistics. So, a 41 percent decline in the jobless rate correlated with a 46 percent drop in the city’s homeless population.

That’s almost certainly not a coincidence.

But while homelessness tracked with job availability, the incidence of homelessness in Alexandria has surprisingly moved inversely to the supply of affordable housing. Our city has lost most of its housing stock that’s considered affordable since the early 2000s, dwindling from around 19,000 units to about 2,000 units.

This supply has most definitely continued to drop during these past seven years – in fact most observers think the decline has accelerated. And yet the homeless population has been almost cut in half.

What gives?

In one way, this inverse equation makes sense: housing has become more expensive in Alexandria as the economy has heated up, and job availability appears to be the more significant factor in reducing homelessness.

Another educated guess is that as housing costs in Alexandria have climbed higher, people who have received homeless services are leaving the city when they are ready to transition to homes of their own. Then, if they subsequently move back and forth between receiving government-funded housing assistance and paying their own rent, they are doing so in other localities. A comparison of Alexandria’s point-in-time data with that in localities with lower housing costs might illuminate this factor.

The significant decline in Alexandria’s homeless population is also a feather in the cap of our city’s social services providers and nonprofit housing organizations like Carpenter’s Shelter and Community Lodgings. These point-in-time surveys have helped identify who is homeless and enabled services to be tailored to better and more quickly help those who lack housing.

Two additional conclusions from this data: First, significant progress has clearly been made in helping the homeless in Alexandria these past seven years.

And second, despite the seeming contradiction from this data, in order to weather the next economic downturn, we need more low-cost housing – not less.