I was curious on the actual numbers here so I summed it up based on census data. Between greater LA, the Bay Area, San Diego, NY metro, Seattle, Boston, Austin

I was curious on the actual numbers here so I summed it up based on census data. Between greater LA, the Bay Area, San Diego, NY metro, Seattle, Boston, Austin, and DC there are just under 54 million people, or somewhere between 16-17% of the total US population and significantly higher than that for working age population. Also as you said, the vast majority of high-paying jobs in many fields (excluding Oil & Gas and a few others) are going to be in one of those places.