[ringwalt]

I'm not convinced that concentrating tech exclusively in the valley has objective network effects that outweigh the costs.

Regardless, from personal experience most of my colleagues would prefer to live in any large metro area but the South Bay (including friends in Mountain View, some of whom were told in the interview process that Google did not have availability in NYC, Chicago, or Pittsburgh). It's untenable for Google to hugely expand its Mountain View campus (http://www.mountainview.gov/depts/comdev/planning/activeproj...) while its satellite offices, where many employees would prefer to work, are at a standstill. This is driving potential employees on the east coast into Mountain View, where they don't want to be, who end up pricing out working-class families from the bay who are desperately trying to stay there.