This dissertation extends the Grossman-Helpman models of endogenous trade policy formation to incorporate local and global production and consumption externalities, and to allow governments to choose domestic production or consumption policies together with trade interventions. The models presented are among the first to allow environmental quality and the structure of industry protection to be simultaneously evaluated in a political economy framework, when some industry groups lobby their governments for higher output prices. The equilibrium tax and subsidy policies are implicitly expressed as the sum of distinct political support, terms-of-trade, and local and global environmental effects. Whether these effects reinforce or counterbalance each other depends on whether an industry is organized, whether the good is imported or exported, whether the externality is caused by production or consumption, and, in the large-country models, on whether governments set policies noncooperatively or cooperatively. The model results imply a political economy version of Bhagwati's normative targeting principle: governments use the most efficient policy available to satisfy the lobbies, to address the externalities, and, in the noncooperative large-country model, to exploit international market power. All of the initial Grossman-Helpman results (for the small-country model and the noncooperative and cooperative large-country models) are shown to be special cases where governments have only trade policy available and there are no externalities. In the small-country model and the cooperative large-country model, when there are production externalities, the lobbying of a polluting industry usually leads to lower environmental quality than socially optimal, but with terms-of-trade effects or for particular preferences cases the equilibrium policies may induce environmental quality higher than socially optimal. When there are consumption externalities, and the government has consumption (or production) as well as trade policy available, environmental quality will be socially optimal (again, unless governments exploit market power). Thus, depending on the policies available, a local or global consumption externality will be fully internalized, even though polluting industries lobby and production may be distorted. This dissertation also shows that--in contrast to standard economic theory--the use of trade policy alone can lead to higher environmental quality than a more direct domestic policy alone. / Ph. D.

本篇以政府採行租稅混合為為核心，在產市勞市交互運作影響下，作地下經濟與地上經濟的兩部門一般均衡分析。我們不僅從租稅收入面探討租稅逃漏，更將觸角延伸至至政府支出面。最後，以這樣架構下分析公共財的Samuelson條件。 　　本文大致上可分為兩部分，第一部分以數學比較靜態及數值分析，討論政府的租稅工具－直接稅和間接稅，公共財，懲罰工具－逃漏直接稅和間接稅的懲罰稅率，等政策工具對經濟變數尤其是逃漏的影響。第二部分，我們承襲Usher(1986)，討論有租稅逃漏時對政府採行租稅混合稅制下公共財的提供成本，亦即Samuelson條件。 　　第一部分，我們發現：所得稅率和消費稅率提高均使地下勞工比例上升。透過租稅混合效果下，對地下對黑市勞工比例影響不確定。可是隨著消費稅期望懲罰率逐漸提高，所得稅率比消費稅率對地下勞工比例的影響來得大，故租稅混合在此情況下抑制逃漏的效果也將更佳。此外，當原本地下經濟很小及消費稅稅率較高時，則租稅混合抑制逃漏的效果也將不太大。 　　消費稅和所得稅期望懲罰率對經濟體系的影響恰與與消費稅和所得稅的影響相反，而且前者相較於後者更能抑制消費稅逃漏，政府提高這兩種懲罰率均能抑制地下勞工比例，然而卻是以降低地上勞工工資為代價。 　　公共財對經濟體系的變數影響不確定，但是可發現若公共財對地上經濟生產越具生產力越能抑制地下勞工比例。 　　第二部分，我們發現：當查核成本是固定時，在有逃漏情況下，除了得考慮租稅混合稅制下的扭曲成本，亦即租稅混合對稅基的影響，尚得考慮租稅混合稅制下對逃漏的影響。另一方面，公共財對地下勞動比例和消費稅稅基的影響也關係著公共財的提供成本。當查核成本是內生期望懲罰率的函數時，此時查查核成本是非固定的，公共財的提供成本除了受前項的考量因素影響外，尚得考慮租稅混合稅制及公共財對淨查核成本的影響。