“Don’t California my Arizona”—these words can be found on everything from T-shirts to tire covers. The slogan speaks to the fear that the Californians fleeing to Arizona will bring with them the very policies that propelled their exodus. California’s housing shortage tops the list of troubles that Arizonans wish to avoid. The cost of a home in Phoenix is still modest compared to, say, San Francisco or Los Angeles, but the lack of affordable housing is nonetheless a growing crisis in Arizona’s capital. If legislators are hoping to save Arizona from California’s failures, why are they trying to replicate its policies?

“Florida will not allow homeless encampments to intrude on its citizens or undermine their quality of life like we see in states like New York and California,” Gov. Ron DeSantis declared when signing the bill to prohibit homeless Floridians from sleeping in public spaces, which takes effect Oct. 1.

On March 5 San Francisco voters will decide whether their city should issue $300 million in bonds to subsidize the construction of affordable housing. The matter is likely to be approved, given the voters’ track record on similar measures. In 2015 they authorized $310 million in general obligation bonds to subsidize affordable housing. In 2016 they added an additional $250.7 million. And in 2019 they approved a record $600–million bond measure. So what does the city have to show for it all?

Sacramento recently took a major step toward fixing its housing crisis by adopting the “Missing Middle Housing Plan,” which will allow apartments to be built in single-family neighborhoods. In urban-planning lingo, this is “upzoning,” which raises the density limits in designated areas. Low density limits are among the largest contributors to housing shortages nationwide, so Sacramento’s reform is sure to encourage construction.

Most policy discussions about homelessness invariably focus on how to address the “root cause.” This is reasonable enough. If we attack the root of a problem, we expect the branches to wither and die. Presumably, then, we need only to identify the root cause of homelessness to design an effective policy solution. But is there a root cause?