Could this be caused by people emigrating from California?
The weather is a shock to lots of people.
I just sold my house in Seattle and will be leaving next month.
Despite that, it is having an unprecedented net population boom.
Over half of my bay area friends now live in Portland. I left the bay myself (for a new country), but not due to housing costs.
Eventually, making it a rotten place to live for anyone who's not a millionaire had to catch up to it.
Seattle, Portland, Austin, Denver, etc would do well to heed the warning. I'm sure they won't though because "mo' money, mo' problems" is a lesson cities haven't learned yet and there's no reason for them to learn it now.