Earlier quoted context omitted.
> I expect what would really happen if SF just went all in building new housing, is that prices would drop in the city slightly, allowing people to move back into the city, thus increasing demand and increasing prices back to where they were. That seems unlikely to me, based on intuition and my admittedly elementary understanding of economics. It seems very unlikely that a significant increase in the quantity of hous…
It would indeed cause the pricing to drop, but just temporarily until all the new housing stock was filled. Basically, the author is suggesting that (within practical bounds) the demand for housing inside SF is unlimited. I think it's a fair assessment.
Tokyo metro area: 37.8 Million
Mexico City metro area: 21.2 Million
NYC metro area: 20 Million
If demand where truly unlimited, then building up S.F. to Tokyo standards or above over the next few decades should be practical, since that level of demand would provide the funds for the growth. Of course, what is really going to happen is that demand will likely stabilize around or below the 15 million threshold for the entire Bay Area.