The low-income threshold in sf for a family of four is about $120,000. And $150,000 is not far off from that. And even more important, the extraordinary rents in sf more than outpace the higher incomes:
For example, a fair market rent for a two-bedroom apartment in the San Francisco area is considered to be $3,121 (£2,340) per month - nearly twice the 2008 figure of $1,592 (£1,190). In Cincinnati, Ohio, the figure is $845 (£632). This difference (270%) is much larger than the difference in median family incomes (50%).
For example, a fair market rent for a two-bedroom apartment in the San Francisco area is considered to be $3,121 (£2,340) per month - nearly twice the 2008 figure of $1,592 (£1,190). In Cincinnati, Ohio, the figure is $845 (£632). This difference (270%) is much larger than the difference in median family incomes (50%).
https://www.bbc.com/news/world-us-canada-44725026