Here's a good summary: https://techcrunch.com/2014/04/14/sf-housing/ https://techcrunch.com/2014/04/14/sf-housing/ Basically, there are a lot of regulations g

Here's a good summary: https://techcrunch.com/2014/04/14/sf-housing/ https://techcrunch.com/2014/04/14/sf-housing/ Basically, there are a lot of regulations governing what you can build and where. And those regulations have a constituency that benefits from them, namely everyone who already owns a home in the Bay area. If you bought a nice single-family home twenty years ago, you're sitting pretty. You live in a nice area that probably isn't going to change very much (thanks to the regulations), and the steeply rising value of your real estate (thanks to the regulations) is going to fund your retirement very nicely.