Marin County had by far the highest per capita income during that period ($58,004); its per capita income was almost $10,000 higher than San Francisco County, which ranked second in that regard. Of the ten counties in California with the highest per capita income, all but Orange were in Northern California, and all but three are located in the San Francisco Bay Area. Of the three not located there, two are smaller counties located in the Sacramento metropolitan area. Orange County's per capita income ranks last among these ten, and its per capita income is about $5,000 more than that of the state.
Seven of the ten counties in California with the lowest per capita incomes are located in the Central Valley. Two of the remaining three are rural counties in Northern California. This leaves Imperial County, which shares California's portion of the U.S.-Mexico border with San Diego County. All of these counties had populations not exceeding 1,000,000, and all of them are landlocked, with the exception of Del Norte County.

For instance, a business owner who works in the company she or he founded would have to pay an extra 15.3 percent in self-employment payroll taxes compared to someone who merely had a passive interest in the same limited liability company who would pay only income taxes. In other words, the same income earned actively would be taxed at a higher rate than if it were earned passively.

"For long-term savings, investing in low-cost index funds is the ultimate passive strategy," Goudreau says. "As legendary investor Warren Buffett recently told CNBC’s On the Money, 'Consistently buy an S&P 500 low-cost index fund. I think it's the thing that makes the most sense practically of all time.' By not picking individual stocks and, instead, buying a low-cost fund that tracks the market, you pay less in fees and take less of a risk. Then you can sit back and watch your money grow over time."

These days, low-risk bond yields aren’t enough to meet most income needs. When investing in bonds, the income typically comes as coupon payments – contractually guaranteed interest payments at predictable intervals.  There are many kinds of bond income available, so you must strike a balance between reaching for higher income (yield) and limiting risk.