I'd suggest to you that your bay area (really peninsula) focus is a little myopic, and that there is a whole lot more California than the Counties of San Francisco, San Mateo, Santa Clara, Alameda, Contra Costa, Salano, Napa, Sonoma and Marin - heck, each of those counties have different problems.
There are two problems at work. One is the poverty of the Central Valley. I strongly suspect this poverty is caused by more traditional problems, such as lack of economic opportunity, poor educational systems and exploitive corporations.
Then there is the "poverty" that is caused by urban planning issues in urban and coastal California. There are families making six figures who can qualify for affordable housing programs here. In no way should a family bringing in six figures be just barely scraping by, but due to the increasing rent burden that’s where many find themselves.
* The problem is state-wide. Cost burdened or severely cost burdened renters; Far north 42%, San Francisco Bay Area 37.8%, Sacramento Region 38.4%, Central Valley 38.9%, Sierra Nevada 36.8%, Central Coast 42.1%, los angeles and south coast 46.1%, Inland Empire 42.7%
* more than half of California's renters and over a third of homeowners with mortgages face high housing costs
* 8 in 10 low income Californians have unaffordable housing costs
The US census shows that people without means can't afford the living costs are self-selecting themselves away:
* A snapshot of more recent U.S. Census migration numbers shows that nearly three-quarters of those who have left California for other states since 2007 earn less than $50k a year.
Does not negate my point - baring some evidence, its not reasonable to assume that zoning is not the cause of a lack of affordable housing in the San Joaquin Valley.
If they had suggested merely that housing costs are an issue for californians, I would not have argued.
For instance, Stockton leads California rent increases with a 10.4 percent increase in rental price between July 2016 and July 2017 and their home prices have increased 92% in the last 5 years. In a supply balanced market this would not happen as the landlors do not have leverage to increase rent this much, and developers/owners don't have the leverage to sell housing for this much more.
