Tyler Cowen, whose blogging at Marginal Revolution I generally admire, is apparently trying to prove that economists really are nothing more than shills for the wealthy. He quotes vapid blowhard George F. Will, who really is nothing more than a shill for the weathly, and asks

In 1979 the top 1 percent of earners paid 19.75 percent of income taxes. Today they pay 36.3 percent. How much is enough?

This is supposed to be some sort of appeal to fairness, I suppose. “It’s just so unfair that the top 1% of the income distibution bear 36% of the cost of the federal government.”

Let’s just set aside the fact that Will and Cowen are focusing solely on federal income tax, and ignoring the regressive federal payroll tax and state sales taxes, both of which raise the bottom 99 percent’s share of the overall tax burden.

The important point is this: statistics about the percentage of the tax burden born by a given segment of the income distribution are utterly meaningless in absence of data about what percentage of overall income (or wealth, or whatever you think is fair to tax) that segment controls. Even if we instituted a perfectly flat income tax, the top 1% would pay a greater portion of the tax burden than people at the bottom of the income distribution, for the simple reason that they have more income.

The reason that the top 1% pay a heavier share of the federal income tax burden now than they did in 1979 is not that the federal income tax has become more progressive. On the contrary, federal income tax has become flatter since 1979. The rich pay a higher share now because the rich have seen sharper gains than the rest of the population. By and large, most people have gotten richer in the past two decades, especially during the 90s, but the rich have gotten more richer than the rest of us.

My opinion as a utilitarian: Fairness is a useful concept for dividing splitting the cost of pizza between friends, but worthless when trying to determine what share of the tax burden an individual should bear. Economist can tell us about the effects of various tax schemes on economic efficiency, i.e. the total size of the economic pie as measured in dollars, euros, or what have you. But any gains in efficiency brought about by making the tax system less progressive may be offset by the diminishing marginal utility of money. If we shift $100 dollars of the tax burden from Bill Gates to some pauper, there’s a net loss in utility, because that $100 was worth more to the pauper than to Bill Gates, who could afford to wipe his ass with $100 bills if he wanted to. Somewhere in the middle lies the perfect tax system that maximizes utility, but we’re not going to find it by bloviating about fairness.

My opinion as a snarky blogger: You're supposed to post your insightful stuff at Marginal Revolution, Tyler, and post crap like this over at the Volokh Conspiracy, where it fits in well with crap by Barnett and Bernstein.

UPDATE: Dan Chak makes pretty much the same point I do, and then fills in the missing data.