We all know the charitable deduction works. It encourages Americans to give more money away than they might otherwise give. If it didn’t, we wouldn’t have it, or many other tax incentives for that matter.
Deductions and taxes are used, at all levels of government, to encourage behavior we want more of in society and discourage behavior we want less of. We have the mortgage interest deduction to encourage homeownership, and we have sin taxes to discourage consumption of substances deemed harmful, like alcohol or tobacco.