While driving last weekend, I flipped on my local National Public Radio station to hear Bill Moyers yammering away on income inequality. While the subject is important, even if the cure remains elusive, Moyers's selective use of data was appalling.

The Commerce Department reports that personal income fell 3.6 percent in January -- that’s the sharpest one-month dive in twenty years. It sure seems like the Roaring 20s all over again -- people at the top living it up while those down below lose their livelihood.

Moyers conveniently omitted personal income increases of 1.1 percent in November, 2.6 percent in December and 1.1 percent in February. The last two months of 2012 witnessed a huge shift of income forward to avoid any additional liability arising from the expected expiration of the Bush tax cuts at year-end. January's enormous decline was payback.

Maybe Moyers thinks changes in income tax rates have no effect, that the rich willingly hand over more of their earnings to the government. Perhaps he is naive about economics and thinks one number, picked out of a hat, suffices to explain a complex phenomenon. Or, more likely, maybe he was trying to make a point with the most glaring, out-of-sync number he could dig up.

There are lots of legitimate statistics Moyers could have used to make his case. He could have reported that real median household income in 2011 of $50,054 was 8.1 percent lower than in 2007, prior to the recession, and 8.9 percent below the 1999 peak. He could have said that 15 percent of Americans live in poverty (for blacks, the rate is 27.6 percent). These data, among the most authoritative available, are from the Census Bureau's annual report, "Income, Poverty and Health Insurance Coverage in the United States: 2011," released in September 2012.

Moyers could have used lots of other accurate numbers to demonstrate how incomes in the U.S. have stagnated, failing to keep up with even the modest rise in prices. But they would have been a lot less sexy than the biggest dive in income in 20 years. Guilty by omission is still guilty.

(Caroline Baum is a Bloomberg View columnist. Follow her on Twitter.)