California housing shortage
Since about 1970, California has been experiencing an extended and increasing housing shortage, such that by 2018, California ranked 49th among the states of the U.S. in terms of housing units per resident. This shortage has been estimated to be 3-4 million housing units (20-30% of California's housing stock, 14 million) as of 2017.
Source: Wikipedia — California housing shortage (CC BY-SA 4.0)