Sorry for the super-long delay in replying, HN has been particularly flaky at my site.
> If the talent can't afford to live and work in the valley, they won't.
One way to make it affordable for talent to live and work in an area is to increase their wages. There is a point at which Google et. al. would stop increasing wages and just move out of the area, but I strongly suspect that we're very far from that point. Moreover, I was talking about SV businesses increasing wages in SV in order to prevent people from moving out to NYC, or cause folks from elsewhere to choose SV over NYC.
> In short, it's the engineers and designers making it expensive...
Yes and no. An influx of people with a high earning potential into an area with a fixed number of apartments for rent does raise rents. Those rents would be lowered if the city (as a whole) would permit enough housing to be built quickly enough to accommodate the influx of workers.
I totally agree that the best way to bring rental rates back into shouting distance of sanity is to embark on massive build projects. If you look at my comment history, you'll see that I strongly support this sort of thing. I'm just not foolish enough to believe that that sort of project is likely to get started anytime soon. Sure, we've been hearing rumblings from the Mayor's Office. I seriously doubt that any project of his will make a substantial dent in the housing shortage.