SEATTLE, WA – In King County, a renter earning the local median income should only spend about 31 percent of their earnings on rent. If that share increased by even a few percentage points, that renter might end up homeless, according to new research by Zillow.

The Seattle-based real estate company released the research on Tuesday. The main takeaway: homelessness rises more quickly in cities where people spend more than about 32 percent of their income on rent.

In the Seattle-Bellevue metropolitan area, Zillow estimates that a two-point increase in spending on rent would result in 33 more people becoming homeless. After a five-point increase, 84 people would become homeless.

In Seattle, the rent for a one-bedroom apartment is about $1,884, according to the real estate site Rent Cafe. A person earning the Seattle median income, $75,000, is already at the 31 percent threshold.

“Rising rents have long been associated with climbing rates of homelessness. This research demonstrates that the homeless population climbs faster when rent affordability – the share of income people spend on rent – crosses certain thresholds. In many areas beyond those thresholds, even modest rent increases can push thousands more Americans into homelessness,” the research says.

King County is in the midst of a homelessness emergency, literally. The 2018 point-in-time count found 12,112 people living homeless, a 4 percent increase over 2017. Meanwhile, there aren’t enough affordable units in King County for low-income people. In many cases, very low-income people are competing with the homeless for any available units.

And the problem isn’t just confined to larger cities like Seattle, Kent, or Bellevue. Rising rents in one city might cause higher rates of homelessness in the next city, according to the Zillow research.

“A kind of spillover effect may be one explanation for homeless numbers remaining steady or even falling, despite rising rents and worsening affordability. When prices go up in one community, people sometimes move to an area next door for a larger supply of lower-priced homes. After those rentals are filled, homeless rates in that community rise as well,” the report says.

The study concludes that there’s no one solution to the problem.

“Some policies will necessarily create more housing in general, while some will need to be more pointedly focused on creating affordable housing in particular,” the report concludes. “The point is there is no one-size-fits-all approach, because there is no universal template for how homelessness evolves and responds in a given community.”