We usually think we have a good common sense grasp on what’s fair and what’s not. Kwame Anthony Appiah points out that when it comes to tax policy, at any rate, that’s not so, as Thomas Schelling’s research demonstrates:
Would it be fair, do you think, to give poor parents a bigger credit than rich parents? Schelling’s students were inclined to think so. If the credit was going to vary with income, it seemed fair to award struggling families the bigger tax break. It would certainly be unfair, they agreed, for richer families to get a bigger one.
Then Schelling asked his students to think about things in a different way. Instead of giving families with children a credit, you’d impose a surcharge on couples with no children. Now then: Would it be fair to make the childless rich pay a bigger surcharge than the childless poor? Schelling’s students thought so.
But — hang on a sec — a bonus for those who have a child amounts to a penalty for those who don’t have one. (Saying that those with children should be taxed less than the childless is another way of saying that the childless should be taxed more than those with children.) So when poor parents receive a smaller credit than rich ones, that is, in effect, the same as the childless poor paying a smaller surcharge than the childless rich. To many, the first deal sounds unfair and the second sounds fair — but they’re the very same tax scheme.