That's an excellent point. I live in an R1 neighborhood, but a buddy of mine lives in a SFH in an R2. He would technically be allowed to convert his SFH into two 3bd/2ba apartments, he could sell one of them, and profit so much that he would cover his entire mortgage with lots left over. While he'd still face permit challenges, this has been done (legally, with all required permits) on his block. However, this remains a relatively rare situation in SF.

I gotta say, for a moment there, I was a tad bit jealous that he had this option.

Yeah, truth is, if large sections of SF were rezoned for multi story dwellings, property owners might very well benefit, since the value of their land could substantially increase. I'm not sure how this would all work out, but it certainly seems like a possibility.

This is why I think that SF's opposition to new development isn't really driven by property owners who wish to maximize the dollar value of their asset. I think it's rooted more in a very preservation minded populace (not always such a bad thing), a left-leaning hostility to "greedy" developers (not always unwarranted), and a deep suspicion of redevelopment projects that they worry will tear out the soul of a community and replace it with something corporate and soulless (plenty of that has happened). There's also a tendency to leave good enough alone (prop 13 insulates property owners from the tax burden of massively rising property values, and many people just aren't interested in more money once they're happy. If you live in a neighborhood you like just the way it is, and you can easily afford it, what do you care if you could make more money tearing down your house and building an apartment building? You're more interested in making sure that doesn't happen right next to you).

In short, San Franciscans will happily vote against their own economic interests (well, their own asset value maximization) in order to "preserve" what they like about where they live.

While we probably agree that the bay area needs more density, I'd be against tearing out the french quarter in New Orleans, even if that would lower the price of housing there. I personally think that the bay area actually can substantially increase density, both in SF and out, and vastly increase excellent light rail (preferably underground) without tearing down old and interesting neighborhoods, and that the city that would emerge would be a richer and more interesting one.

Truth is, I put "preserve" in quotations, because one of the best qualities of San Francisco has been lost. Interesting people, with a half formed idea that is too strange or misunderstood to be funded as a thing, used to be able to move to SF and give it life. That's largely gone, because it's nearly impossible to live in SF without working so hard to pay the rent that you have no time left for things that nobody understands well enough to pay for. You do have to ask yourself what you're preserving and what you're losing. Interestingly, I actually think this will influence tech as much as the arts. There are now career paths in tech that are lucrative and are available more in SF than anywhere else, but there's certainly a wild, misunderstood, and creative side of tech that nobody will fund because they just don't understand it yet, and that requires the freedom of time to tinker. SF may lose this just as surely as it loses interesting non-tech arts and culture.

In fairness, this has also happened in the vastly more dense and urban city of New York. I found this link about the galapagos art project moving to Detroit very interesting: "You can’t paint at night in your kitchen and hope to be a good artist. It doesn’t work that way… If the core competitiveness of the big apple is culture, but actually being an artist in New York City costs you a full time career in another industry, then the best and brightest – the ones our meritocracy would obviously miss the most - won’t allow their work to suffer just to be among our tall buildings."

http://www.galapagosdetroit.com/whydetroit/

Not sure this will work, but my guess is that Patty Smith was right when she said "New York has closed itself off to the young and the struggling. But there are other cities. Detroit. Poughkeepsie. New York City has been taken away from you. So my advice is: Find a new city."

I'm all for building more density in SF, but finding a new city sounds like good advice.