The government supported American Dream of home-ownership was incredibly myopic.

"People don't question that buying a home is a good thing, it's just something they've always been told and now assume to be true" — Callum Williams, Senior Scholar, Economist

After WWII the US had a bunch of programs to incentivize home-ownership. The problem was that once people got their homes, they became really adamant about maximizing the growth of their property value and retaining their small-town feel. The population kept growing and high-density areas became even higher density. So now we are stuck with homeowners that fight all legislation to "build up." This limits the supply of housing and pushes housing prices astronomically high. Welcome the Millennial generation who have no affordable homes to live in.

But — Switzerland

Switzerland might indicate that home ownership isn't the way to go. The land with the 2nd highest quality of life has the lowest (38%) home ownership rate of the OECD countries. Housing prices have risen just 70% since 1970. While in Britain, average housing prices have skyrocketed 346%.

So what if we made SF a rent-only city?

Make SF a terrible real estate investment choice. Create an environment where 90% of the housing is rented and where land owners have no power to prevent development. Make all housing "affordable housing" where sale and rental prices are heavily regulated.

The city would build upwards, prices would go down, and (heaven forbid!) teachers will finally be able to afford to live in the city they work in.