It would make even more sense to compare to those with relevant education:

Though Asians are only 5% of US, they are maybe 1/3 of Tech degrees, which is consistent with Google hiring.

Similarly for women.

Very roughly, Google seems to be selecting in a fairly unbiased fashion from the candidate pool.

Where the issue gets more sticky is at upper levels of management, which are fairly male dominated.

Good call. According to: http://www.bayareacensus.ca.gov/bayarea.htm it looks like 52% are White (42.4% White and Non-Hispanic), 23% are Asian, and 6% as African American. So this would suggest that the difference between Google and the Bay Area is still significant but not as much as between Google and America as a whole.

There are two plausible arguments there.

You either have to go one step further and break that down by available tech talent to be recruited, with the premise being that you can't magically manifest a certain % of white/hispanic/black/asian tech employees if they're not available locally (eg if the population is 12% hispanic, but only 5% of the tech employees available locally are hispanic; that presents a very difficult recruiting scenario).

Or the argument is that a company like Google can afford to recruit nationally and relocate whatever demographics they see fit to the bay area, such that local restrictions do not apply as much to them. If the local bay area pool of tech talent is 3% black, and the national pool is 6% black, Google can afford to relocate black employees from around the US to bolster their diversity efforts locally if that's their aim.

On the other hand, I'd say most of the population surrounding the Google HQ are there because they got employed by Google or another tech company, not the other way around. The pool of candidates for these companies is global (restricted to the quotas the visas allow).

That isn’t true historically, it definitely wasn’t true in the late 19th century when Asian immigration to the bay area started, nor after the Vietnam war. The Bay Area has attracted Asians way before google or even tech existed there.

Well of course. I was just counterpointing to my parent, that comparing Google employee demographics to the demographics of the area around HQ doesn't really tell us anything.