Columnist who accuses Douthat of not having a clue, has no clue

Yahoo finance columnist Dan Gross thinks he's really nailed Ross Douthat in his column NYTimes Columnist Douthat Needs a Clue on Taxes. He writes:

I'm not quite sure where Douthat pulled that $94,000 figure from. Perhaps from the same place where he got the notion that a family making $94,000 "pays 15 percent in federal taxes." Look at the Internal Revenue Service's 2010 tax tables and you'll see that a family filing jointly, earning $94,000, is squarely in the 25 percent tax bracket. Because the first $68,000 of their income is taxed at lower rates, their total federal income taxes would come in at about 17 percent.

But there's more to federal taxes than income taxes, especially when you're in the lower tax brackets. This fictional family would also pay payroll taxes for Social Security (4.2 percent, thanks to this year's payroll tax cut) and Medicare (1.45 percent). So a family of four making $94,000 is already paying about 22.5 percent of its income in federal taxes, and is looking at a 30.65 percent marginal rate on income earned up to the Social Security cap.

This is how the math actually works out for this family of four making $94K:

Adjusted Gross Income: $94,000
less Standard deduction: $11,400
less Exemptions: $14,600
Taxable income: $68,000

Tax $9,369

less Child tax credit: 2,000
less Making work pay credit: 800
Tax owed after credits: 6,569

Marginal tax rate: 15%
Effective tax rate: 11%

So, the tax they are paying is actually 11%. Even if you include social security and Medicare payroll taxes, which total $7,191, the effective tax rate would still come in under 15%.

Stunningly sloppy.