In Kalodner v. Commonwealth, 150 Pa. Commw. 248, 615 A.2d 900, 904 (Pa. Cmwlth. 1992), the Court considered whether an income tax unjustifiably discriminates against self-employed persons because it taxes as income the contributions to a retirement plan made by a self-employed person but does not tax the contributions to a retirement plan made by an employer for the benefit of an employee. The Court held that the tax was justified because the contributions made by self-employed persons come from money they actually received as income, but the contributions made by employers for the benefit of employees may not have been actually or constructively received by the employees due to substantial limitations and restrictions on the receipt of benefits under the retirement plan. Id. at 905.