That is because we on the west coast have zoned most neighborhoods to single family housing, and that is a direct cause of our housing supply constraint and therefore our high housing cost. It would be trivial to replace a fraction of that housing with enough housing to meet demand if we rezoned.
It is a direct cause, but not the only cause. The fact that virtually all job growth is in these cities is equally if not more to blame. As a Seattle resident who was priced out of a succession of neighborhoods through grad school, I can't help but wonder why we need so much growth. It's not like there's a shortage of employment opportunities.
