Excise Tax on a Non-Uniform Pricing Monopoly: Ad Valorem and Unit Taxes Compared

In this paper, ad valorem and unit taxation are compared on a model that allows for various monopolistic pricing policies, including uniform pricing and all three types of Pigouvian price discrimination. It shows that, for any given unit tax on a nonuniform pricing monopoly, there exists an output-neutral ad valorem tax rate that gives rise to a higher tax yield than the unit tax and there exists an ad valorem tax rate that welfare dominates the unit tax not only in the aggregate sense but also in the Pareto sense.