氮氧化物作為多種二次污染物的前驅物，對環境與人類健康造成重大危害，已
成為各國空污治理的重點項目之一。本研究以台灣高屏空品區為例，建立一套涵
蓋五年期、並納入排放權儲存與借用機制的氮氧化物排放權交易模型，探討不同
彈性機制設計對市場運作、廠商行為與減排成本的影響。模擬結果顯示，引入儲
存與借用機制有助於提升市場參與度與交易頻率，並能平抑排放權價格波動，避
免廠商將減排行為集中於特定時期，有助提升市場穩定性。然而，其對整體減排
成本的抑制效果相對有限。此外，若將國營與泛國營事業排除於市場外，整體平
均減排成本將顯著下降，顯示其高排放量與高邊際減排成本對市場效率造成不利
影響。最後，在管制強度逐期變動的情境下，兼具儲存與借用功能的制度設計，可
提升廠商調度與應變能力，促使其採取更具策略性的排放行為，進一步增強市場
的彈性與調節效果。

Nitrogen oxides, as precursors to various secondary air pollutants, pose significant threats to both environmental quality and human health. As a result, they have become a major target of air pollution control policies worldwide. This study focuses on industrial firms located in the Kaohsiung- Pingtung Air Quality Region of Taiwan. We develop a five-year intertemporal emissions trading model for NOₓ that incorporates permit banking and borrowing mechanisms. The model is used to evaluate how different flexibility designs affect market performance, firm behavior, and abatement costs. Simulation results indicate that while the introduction of flexibility mechanisms enhances market participation and trading frequency, their impact on reducing total abatement costs remains limited. However, complete flexibility mechanisms are effective in smoothing permit price fluctuations, thereby preventing firms from concentrating abatement efforts in specific periods and improving overall market stability. In addition, excluding state-owned and quasi-state-owned enterprises from the trading market significantly lowers average abatement costs, highlighting the negative impact of their high emissions and marginal abatement costs on market efficiency. Finally, under scenarios where regulatory stringency varies over time, systems with both banking and borrowing functions allow firms to better plan and adjust their emissions strategies. Such mechanisms promote more strategic behavior and enhance the adaptability and responsiveness of the trading market.