As I posted previously above, but was perhaps missed …

Months of inventory is more important than the raw number.

San Diego is ahead of the other markets. The reduced inventory is the effect of people who thought they might want to sell and possibly move up, getting out of the market. What remains is a higher majority of those who have to sell because they are moving, can’t afford it, facing foreclosure, etc, as well as those who inherited their homes, and those who have held for a long time and need to downsize.
We are likely to see a similar effect in the other SO Cal markets next year.