在全球永續發展趨勢下，企業參與永續倡議對資金成本的影響已成為資本市場關鍵議題。本研究旨在探討台灣上市櫃綠能概念股加入「科學基礎減量目標倡議」（SBTi）對融資成本之影響，以2015至2024年為樣本期間，在排除未借款及非屬固定利率之樣本後，進一步檢驗SBTi的降息效益是否會因借款期限與企業規模而存在顯著差異。實證結果顯示，在全樣本中加入SBTi與借款利差呈顯著負相關，顯示加入該倡議能向市場傳遞落實減碳的正向訊號，進而降低整體融資成本。然而，交叉分析後發現此降息紅利會因授信期間長短而有所不同，效益僅顯著存在於短期借款中。研究結論指出，在短期授信實務上，減碳承諾能有效發揮訊號傳遞作用；反之，面對長天期授信時，銀行基於未來高度不確定性、中長期執行風險及潛在的漂綠疑慮等因素，使定價策略回歸保守，較難給予企業長期的預先讓利。;Under the global trend of sustainable development， the impact of corporate participation in sustainability initiatives on the cost of capital has become a critical issue in capital markets. This study aims to investigate the impact of joining the Science Based Targets initiative (SBTi) on the financing costs of publicly listed green energy concept stocks in Taiwan. Based on a sample period from 2015 to 2024， and after excluding observations without borrowings and those with floating interest rates， this study further examines whether the cost-reduction benefits of the SBTi vary significantly across different loan maturities and firm sizes. Empirical results demonstrate a significant negative correlation between joining the SBTi and borrowing spreads within the full sample， indicating that joining the initiative effectively transmits a positive signal to the market regarding a firm′s commitment to carbon reduction， thereby lowering overall financing costs. However， sub-sample analysis reveals that this interest rate concession varies depending on the loan maturity， and is significantly present only in short-term borrowings. The findings conclude that in short-term credit practices， carbon reduction commitments can effectively exert a signaling effect. Conversely， for long-term credit， banks revert to a conservative pricing strategy due to factors such as high future uncertainty， mid-to-long-term execution risks， and potential greenwashing concerns， making it difficult to grant firms preemptive long-term interest rate concessions.
