This dissertation contains three essays. They are "On Optimal Excise Taxes: Becker’s Household-Production Approach", "The Pricing of Public Intermediate Goods Revisited", and "Piecemeal Design and Reform of Commodity Taxes". In the first essay, Becker’s household production model is used to investigate optimal excise taxes. We are particularly interested in what can be said about the optimal tax structure from the information of household production activities and the new insights that can be gained into the optimal tax structure by using Becker’s approach. In the second essay, we revisit the pricing of publicly produced inputs for competitive downstream industries under a general equilibrium setting and with a general production technology. We emphasize the dependence of the price structure of the private sector upon public prices and explore the consequences on the public pricing rules with such a dependence. In the third essay, we consider the design and reform of commodity taxes with a given general income tax. The major part of the paper investigates tax reforms which are Pareto-improving from the status quo, with and without lump-sum taxes. / Ph. D.