With Tax Day 2007 almost a week away, policy experts, legislators, and the media are examining the biggest anomaly in the U.S. tax code: the Alternative Minimum Tax (AMT). Aimed at the 155 richest families who paid zero taxes in 1969, the AMT failed to reach 2,824 untaxed rich families in 2003, while the numbers paying it topped three million. Via a succession of "patches" raising AMT's exemption level in recent years, Congress has held the number of AMT taxpayers steady. But as the inflation brings more people within AMT's reach, the cost of these patches increases. As we have noted, extending the patch through 2007 would cost $45 billion; through 2008, $100 billion. Outright repeal of the AMT would cost $700 billion over ten years, assuming the Bush tax cuts are allowed to expire; $1.3 trillion if they are extended. If Congress decides it can't afford another patch, the number of taxpayers subject to AMT this year will shoot up from 3.5 million to 23.4 million, according to the Tax Policy Center. In honor of Boston's historical role in addressing anomalous tax policy, let's consider the Boston Globe's editorial resistance to just tossing the ATM overboard entirely: The better option is to let lapse the Bush tax cuts for the richest, set a minimum income standard for the AMT, index it for inflation, and then tighten up the exemptions that let some wealthy Americans avoid taxes even under the AMT. As it stands, the alternative minimum isn't keeping them from exploiting a plethora of tax shelters, but it is squeezing far less affluent Americans.

• See also the front-page story in today's New York Times.