The Obama campaign is running an ad claiming that Mitt Romney pays a lower tax rate than that of the average American.  Following the ad's release, PolitiFact published an article rating it as "Half-True."  From the article:

There are two main ways to make this calculation, and they lead to opposite conclusions. While we believe that including payroll taxes in the calculation offers a more accurate picture of what the American public pays the IRS, it's also true that the Obama ad didn't specify which measurement it was using, and in fact used a figure for Romney -- 14 percent -- that was based on income taxes alone. On balance, then, we rate the claim Half True.

Unfortunately for PolitiFact, their analysis completely misses the boat.  First, as pointed out by Just Facts in rebutting FactCheck.org last week, Romney pays substantial corporate taxes, something both FactCheck.org and PolitiFact fail to account for in their respective analyses.  According to Just Facts President James Agresti in a phone discussion:

Just Facts and the nationwide accounting firm Ceterus did a detailed analysis based on Romney's 2010 federal tax returns. We found that when accounting for all federal taxes, Romney pays a 1.6 to 2.3 times higher rate than that of the average American.

Why is this important?  As the Congressional Budget Office notes, "[u]nder CBO's assumption, the highest income quintile paid almost 80 percent of the corporate income tax during the 2007-2009 period."  Clearly, this is very relevant to Romney's tax rate.

Second, the PolitiFact analysis ignores data cited by its own resource.  The article cites the Tax Policy Center to look at what tax levels are at for all income quintiles.  However, PolitiFact fails to note that the Center's chart (the same one cited in the article) shows that the top 1% (which Romney definitely falls into) pay 7.7% of their income into the corporate tax structure.

What does this mean?  It means Romney pays a far higher tax rate than that which PolitiFact, FactCheck.org, and Obama claim.  It means the Obama ad is "Pants on Fire" false.  And it means that PolitiFact either needs a better fact-checker or is being purposefully dishonest.

Note: I reached out to a PolitiFact editor with a request for comment about these inaccuracies, but as of publishing time had not received a response.

Dustin Siggins is a policy and politics blogger who regularly contributes to HotAir.com, HotAir.com's Green Room, Race42012.com, and RightWingNews.com.  He is the co-author of a forthcoming book on the national debt with William Beach of The Heritage Foundation.