The Bay area is way more complex than this simplistic trichotomy. The north bay alone (north of Golden Gate) is completely different to the peninsula and east b

The Bay area is way more complex than this simplistic trichotomy. The north bay alone (north of Golden Gate) is completely different to the peninsula and east bay. (Marin is also very different to Sonoma county, the top of the bay area). As work/jobs have changed the blue collar San Franciscans have been squeezed out to the 'burbs and a similar situation has occurred in the south bay with people squeezed out of the suburbs to the eastern x-urbs, until recently a very long commute to work.