Apparently, during the last downturn that threatened Italy, home owners were so stubborn, they held out and prices were contained. That could all be hearsay of course.
I think this is what a lot of people are waiting for, especially in the higher price bracket. I am not an expert like so many here, but it seems to me the air is thick with tension, as a relentless tug-of-war takes place. The patient waiters will probably win out, because they have less to lose in this. Maybe if there are enough people who want to sell but don’t actually need to, it will have some stabilizing effect, but I see SoCal as a transient place, and people move on, which might explain some of the volatility in the first place.