Virginia Postrel writes,

most Americans want the tax system to do three things: to be progressive, to treat households with the same incomes equally, and to treat all individuals with the same incomes equally, whether or not they’re married.

The problem is, we can have any two of those things at the same time, but not all three. No matter how often politicians and various interest groups suggest otherwise, no technical fix can eliminate the marriage penalty while preserving progressive taxation and ”horizontal equity.”

For Discussion. Would the trade-off between horizontal equity, progressivity, and having taxes be independent of marriage still exist with a consumption tax?