Human behavior is always complex and is rarely capture merely by a single number like "Rent". Yes, rent is the #1 problem in San Francisco and maybe even Calif

Human behavior is always complex and is rarely capture merely by a single number like "Rent". Yes, rent is the #1 problem in San Francisco and maybe even California, but it is high because there is a lot of demand. Even building a million units might not make a serious dent in the rent pricing, because as the housing quality would improve more people would move in, and end up like New York: high rents and high density. There are some unique features of the SF market: 25% of immigrants that will show a different elasticity (they literally cannot move to another state, it would be illegal), but at the same time immigration hostility means that people running out of visas will not be renewed, and then the general situation that moving out is more cumbersome, risky, and uncertain meaning it happens a lot less. I wouldn't count on this to mean that rents will crash a lot more, but there might be a new equilibrium that is a bit lower.