A couple of observations: 1) In the segmented model, the cross-segment elasticity limits the impact of high-end supply on lower-segment prices, but that applie

A couple of observations: 1) In the segmented model, the cross-segment elasticity limits the impact of high-end supply on lower-segment prices, but that applies just as much to the impact of _high-end demand_. Yet the same people who reject high-end supply as a solution are much more likely to believe in high-end demand as a cause (those damn techies pushing housing prices up!). 2) There is a significant number of singles with high-paying jobs in San Francisco who are living with roommates, in tiny studios, etc. These people who would live in much larger and better housing in any other city. Thus there is a good reason to believe that the cross-segment elasticity in San Francisco is actually quite high. 3) In general, nobody believes in Economics 101 when it comes to policy, unless it aligns with their other preferences.