In Amidon v. Kane, 444 Pa. 38, 40-41, 279 A.2d 53, 55 (1971), the supreme court considered whether the Tax Reform Code of 1971 violated constitutional principles of tax uniformity. The court noted that the statute imposes "a tax 'for the privilege of receiving, earning or otherwise acquiring income from any source whatsoever . . . .'" Amidon, 444 Pa. at 51, 279 A.2d at 60 (quoting Tax Reform Code of 1971). The court then stated that: The holder of tax exempt Pennsylvania securities certainly enjoys this privilege of receiving income yet is not taxed for the privilege but instead is given a tax preference. This situation is manifestly contrary to our holding . . . that a tax upon a privilege ". . . must apply to all who share the privilege." In addition, despite the existence of a legislative policy favoring this type of tax preference for state and local obligations of this Commonwealth, such a legislative policy cannot prevail over a clear constitutional mandate of uniformity. Id. at 51, 279 A.2d at 60-61. In stating that the exemption violated principles of uniformity, the court did not indicate that the violation was the taxation of earned income as opposed to unearned income. By referring to the statutory privilege of "receiving" income rather than "earning" income, the court made clear that the uniformity violation was the taxation of interest income, but not interest income received from an obligation of the Commonwealth or its political subdivisions.