Three essays on taxation, environment, and welfare

My dissertation examines theoretically the effects of environmental taxation on welfare in various cases. Using a general equilibrium model, the first chapter shows that a Pigouvian tax provides a larger welfare gain than an output tax, since it induces substitution among inputs as well as reduction in output of the dirty good, while an output tax induces only the output reduction. Using data for China and the U.S., numerical simulation results show that the potential welfare loss from not being able to use a Pigouvian tax is much larger in developing countries than in developed countries. The second chapter focuses on the fact that recycled material needs reprocessing to be substitutable for virgin material. Reprocessing uses resources and, in the process, generates pollution. Incorporating these 'imperfect' characteristics into a simple general equilibrium model, I examine how these realistic factors affect the structure of taxsubsidy schemes when the Pigouvian taxes are not available. A generalized Deposit-Refund system can achieve the optimum if illegal dumping is not taxable. Without a Pigouvian tax on illegal dumping, recycling is subsidized for its role in diverting illegal disposal into proper disposal. If Pigouvian taxes on neither illegal disposal nor waste from imperfect reprocessing are available, a combination of output tax on reprocessed material and subsidies for clean inputs can be used to restore the optimum. In the process, another reason to subsidize recycling emerges: recycling is a clean input for imperfect reprocessing. The third chapter focuses on the validity of the results obtained in the first chapter in the case of two vertically-separated oligopolies where the upstream industry is polluting. Using an analytical partial equilibrium model, I show that a tax on pollution is potentially superior to a tax on intermediate good, since the former can utilize both the upstream firms' input substitutability and the downstream firms' input substitutability, while a tax on intermediate good only utilizes the downstream firms' input substitutability. I also derive the conditions that government can improve social welfare through various revenue-neutral tax reforms.