二氧化硫作為影響環境品質與公共健康的重要污染物，已成為各國重點管制與監測的對象。本文以台南、高雄與屏東地區廠商之二氧化硫排放為管制對象，建構一個涵蓋五年期且具借用與儲存之彈性機制的排放權交易模型進行模擬，探討不同的借用、儲存制度設計與減量標準，對市場價格、受管制廠商之減量行為與減量成本的影響。相較於既有文獻多聚焦於碳排放與國家層級政策，本文強調空氣污染物與地方市場的結合，補足相關研究的不足。模擬結果顯示，引入儲存與借用機制雖有助於提升市場參與度與交易活躍度，但對整體減排成本的抑制效果相對有限，總減量成本僅下降約5%。進一步分析發現，來自工業化學品與電力業的污染大廠因具備減量成本優勢，故在排放權市場中扮演主要供給者的角色，對市場穩定性與排放量的控制成效具有關鍵影響。此外，當設定相對嚴格的減量目標時，整體廠商的平均減量成本反因規模經濟效果而顯著下降。

Sulfur dioxide (SO₂), as a major pollutant affecting environmental quality and public health, has become a key target of regulation and monitoring in many countries. This study focuses on SO₂ emissions from firms located in Tainan, Kaohsiung, and Pingtung, constructing a five-year emission trading model incorporating flexible mechanisms such as allowance banking and borrowing. The model simulates how different designs of banking/borrowing systems and emission reduction targets influence market prices, regulated firms’ abatement behavior, and overall abatement costs. Unlike most existing literature that centers on carbon emissions and national-level policies, this study highlights the integration of air pollutants and regional markets, addressing a gap in the research. Simulation results indicate that while the introduction of banking and borrowing mechanisms enhances market participation and trading activity, their effect on reducing overall abatement costs is relatively limited, with total costs decreasing by only about 5%. Further analysis reveals that major polluters in the industrial chemicals and power sectors, due to their cost advantages in emission reduction, act as primary suppliers in the emissions market, playing a critical role in market stability and emission control effectiveness. Additionally, under relatively stringent reduction targets, the average abatement cost across firms significantly decreases due to economies of scale.