Some people, including Republican presidential candidate Mike Huckabee, would like to eliminate the federal income tax in favor of a sales tax. They say that, among other things, this would make like life easier, eliminating the need to file your income taxes.

There are, unfortunately, several problems. One is that nearly all states have an income tax, too. So you'd still have to do your taxes. Indeed, most states want to know your federal "adjusted gross income" before they figure what you owe them.

Another problem is that if federal taxes apply only to sales, then the tax burden shifts downward on the income scale. That's true because the less money you have, the bigger percentage of it you spend. People with a lot of money can save a lot, thus avoiding sales taxes. And if they pay less in taxes, then others have to pay more, unless what's proposed is a tax cut. But Mr. Huckabee says his proposal is "revenue neutral."

To offset this characteristic of the sales tax, the proposal he embraces — known by promoters as the "FairTax" — would have the federal government actually give money to poor people. But there are problems with that, too.

For one thing, that still leaves the middle class paying a higher portion of their income in taxes than the more affluent.

President George W. Bush appointed a bipartisan commission a few years ago to consider various approaches to tax reform that would entail much simplification. The panel looked at simplifying the income tax and at adopting the sales tax and a variant called the Value Added Tax. It concluded that a cash grant to protect the poor from being hit harder by a sales tax than by the income tax would cost $600 billion in 2006, almost a fourth of the federal budget.

It would be difficult to administer. The federal government would need to know about the incomes of millions of people. That fact puts a damper on the dream of eliminating the IRS. There's not much point in closing an agency only to move its kind of work to another.

(Proponents of the "FairTax" want to transfer the job of collecting taxes to the states, given that sales taxes are already collected there. That opens a big can of worms, worthy of another editorial.)

Then there is the matter of cost. Proponents of the FairTax say it would be a 30 percent tax. (Actually, they say 23 percent, and they have a rationale. But, using the language the way people normally use it, the rate would be 30. An item priced at a dollar would cost $1.30.)

That puts things in uncharted territory. How much cheating happens when sales taxes are so high? How much spending would move to black markets? People can only guess. The presidential panel worries that it would be a great deal, in part because cheating would be easier. With the income tax, both the employer and the employee file paperwork; that fact tends to keep both in line. But with the sales tax, the buyer doesn't file, only the seller.

Anyway, the presidential commission rejects the notion that a 30 percent sales tax could replace all federal taxes. It says a 34 percent tax would be needed to replace only the income tax.

Meanwhile, keep in mind that the tax is only that low if, as designed by the proponents, it covers everything except education. Everything includes health care.

(On the Internet, the federal study is at www.taxreformpanel.gov. Pro FairTax material is easy to find.)

The sense that there must be a better way to handle taxes than the current system is widespread, understandable and healthy. A tax code that is a zillion pages thick is a likely target for reform. The search for a better way should continue. The simple substitution of a sales tax — even modified to protect the poor — isn't it.