[dragonwriter]

> If rich people’s housing consumption were bounded by their own needs for personal residences, it would be easy to outbuild them.

Globally, certainly; locally in particularly attractive areas? Probably not even if that were the case.

> This thread proposes that rich people consume many more homes than they can actually live in.

Which is obviously true, 2nd through nth homes that are kept idle most of the year, or even for years at a time, are a thing, and a person can't actually live in more than one at a time.

> So why don’t they draw some of those homes from other markets?

They do. But there's enough rich people that want to draw some of their consumption from SF to eat up quite a lot of expansion, until you actually make SF unattractive to rich people.