Well, as you might expect, affordability is the most common concern, and a longer commute is worth the savings on housing costs. But these days, there’s often a lot of two-way traffic, particularly between Alameda and Contra Costa counties.
When they move out of state, Bay Area (and California) residents mostly choose states with no income tax like Texas, Nevada, or Washington, adjacent states such as Arizona and Oregon, or states with major high-tech centers — all of which have much lower costs for housing and basic needs. At the same time, California has some of the highest income tax rates of any state in the country, and the legislature is actually considering increases on affluent residents!
Meanwhile, people moving into the Bay Area come from just about everywhere — including a significant, but declining number from other countries. Please contact the Geek for a full report.