Every heard about Vacancy Truthers? They are people who deny that we need to build more housing. I hadn't heard of them either until I started attending housing forums to advocate for building more housing. Darrell Owens has written an excellent article about the Vacancy Debate. Please read it.
It feels wild to read a paper about Homeless in America, Homeless in California by John M. Quigley, Steven Raphael, and Eugene Smolensky. The 1990s seemed so long ago, and we can only dream about vacancy rates and rent to income ratios like this.
Instead, they saw the opposite.
They then looked at vacancy rates, rise in rents, and rent to income ratios. Bingo, that's why California is a homeless magnet. California is special because we have the most extreme housing scarcity. For each increase in vacancy rate from an average of 6.7%, there would be a 25% drop in homelessness. The opposite can happen. If vacancy drops, conditions allow landlords to raise rents, and more people fall into homelessness.
Economists broadly agree that a 5-7% vacancy rate stops rents from rising. Los Angeles' vacancy rate was 4.2% in 2017.
California has made a different choice. We seek only to staunch the bleeding, but not to heal the patient by bringing rents down. In the 6th Round of the Regional Housing Needs Assessment (RHNA), cities only have to plan for enough housing to raise the rental vacancy rate to 5% and the owner vacancy rate at 1.5%.