Even though California’s San Jose-Sunnyvale-Santa Clara metro area, which covers Silicon Valley, has the third-highest cost of living in the country (after Honolulu and New York-Newark-Jersey City), its adjusted wage ($1,706) is still more than $400 higher than the runner-up, the California-Lexington Park, Maryland, metro area.

But in the Santa Cruz metro area, just west of Silicon Valley and with a similarly high cost of living, the average weekly wage is just $888. That means metro Santa Cruz has one of the lowest adjusted average weekly wages in the country: $737, or 357th out of 381 metro areas. Similar patterns exist in several other California metro areas, including Santa Rosa, Napa, Oxnard-Thousand Oaks-Ventura and Salinas.

http://www.vanityfair.com/news/business/2014/05/san-francisco-income-inequality-developing-nations

"The figure cited by the Chronicle is the Gini coefficient, which measures income distribution on a scale of 0 (everyone shares wealth equally) to 1 (all of the nation’s wealth is concentrated in the hands of one person). Sweden landed at a .25, and Denmark came in at .24. The United States, per the World Bank, earns a .45, with San Francisco at .523—worse than Rwanda’s .508, and barely better than Guatemala’s .559."