The same logic that applies to nonitemizers extends to itemizers. A floor under their itemized giving would increase revenues with almost no loss in their charitable giving. In fact, a common floor under both itemizers and nonitemizers is far superior as a matter of tax policy to separate rules applying to each. Not only would a common floor provide for greater simplification for the same amount of revenue loss, it generally would induce more charitable giving than would separate rules. In effect, a floor under itemizers raises revenues that can be spent more efficiently on providing a lower floor for nonitemizers than might otherwise be required.
Floors are also extremely valuable in solving other problems.
Simply extending an open deduction to nonitemizers raises serious questions of complexity and compliance. Fortunately, with the use of a floor, it is possible to minimize any increased complexity by continuing to remove small givers from itemizing any of their giving. None of the recent proposals has really tried to strike such a balance, but they have put the charitable deduction for nonitemizers on the table. Given that some enactment is likely when both parties are presenting proposals, significant attention is required now to issues of proper tax design and policy. The analysis here summarizes some research being performed at the Urban Institute with Joseph Cordes and John O'Hare.