A recurring theme in national tax debates is the idea that everyone should pay their “fair share” of taxes. While that aspiration’s validity is widely taken for granted, the stark reality is there’s no such thing as a “fair share” of federal taxes. To understand why, let’s first scrutinize what’s meant by “fair.” When paired with “share,” the most fitting definition is “reasonable, right and just.” If the United States government were limited to its only morally sound function—protecting rights, liberties and lives—perhaps one could entertain the theoretical notion of a “reasonable, right...