There can be net decrease in population if housing gets less intensively used. If I used to share an apartment in San Jose with a roommate, but that roommate mo

There can be net decrease in population if housing gets less intensively used. If I used to share an apartment in San Jose with a roommate, but that roommate moves out to go to Austin and I decide I'd rather have the extra space to myself, then the local population has gone down. And as I understand it, there's room for quite a bit of this to happen in the Bay Area. There are plenty of stories about really dramatic numbers of people cramming into two-bedroom apartments.