Over the weekend I hipped to the fact that the California Franchise Tax Board — the state equivalent of the IRS — publishes a great deal of statistical data on the finances of Californians. It led me to wonder if it would be possible to produce a local version of the famous Mother Jones inequality charts that have pretty much launched a social movement.

And you kind of can! The state has reports breaking down household earned income per county dating back to 1980. This allows us to fashion up a Humboldt County version one of the more arresting Mother Jones charts, the one that shows the change in the share of total national income among various income classes.

Three differences.

One: The Franchise Tax Board, unfortunately, doesn’t break things down according to the lingo we’ve all become familiar with — top one percent, bottom 99 percent, etc. Rather, we’re looking at income according to certain set income classes.

Two: Though the state does have data going back to 1980, it adopted its current breakdown — 26 earned income ranges, from $0 or less to above $1 million — in 2001. So we’re going from that date to 2009, which is the last year for which statistics are available. (Also, I’ve boiled the FTB’s 26 income brackets down to six.)

Third: Remember, this is earned income — that line on your taxes that pops up after you take your standard deductions. The one you use to look up your taxes in the tax tables. So there are plenty of households — about 2.1 percent of the total, in 2010 — that have no earned income at all, or negative earned income.

Here’s what that looks like:

Now, see how the black line — the lowest of the low-income households, drops off the chart in 2006? That’s because total earned income among that group fell astonishingly rapidly with the onset of the financial crisis — down from -13.2 million in 2001 to -248.2 million in 2009. 

Otherwise, things track roughly well with the national figures, with the wealthy generally getting a larger share of the wealth and the less wealthy getting poorer. Humboldt County’s top of the topmost suffered some setbacks in 2009, but they’re still (relatively) well ahead.

If you want to take a stab at quantifying the number of households belonging to each income bracket, here’s a pie chart of what the breakdown was in 2010. 

Or:

• Above $400,000: The top .3 percent.

• $150,000 - $400,000: The second-tier 2.4 percent.

• $60,000 - $150,000: The third-tier 18.5 percent.

• $21,000 - $60,000: The third-from-the-bottom 40 percent.

• $0 - $21,000: The penultimate 36.5 percent.

• Less than $0: The bottom 2.1 percent.

I’ve still got all this data sitting here. Any requests?