| 摘要: | 水資源為企業營運中不可或缺的重要生產要素。然而，隨著氣候變遷日益加劇，極端乾旱與強降雨事件發生頻率升高，水資源管理逐漸成為企業與利害關係人高度關注的議題。在台灣，儘管年平均降雨量約為全球平均的2.6倍，但受到地理與氣候條件限制，可實際利用的水資源比例偏低，使得水資源情勢具高度不穩定性，進一步加劇產業運作的不確定性與風險。
本研究以台灣498家上市公司為樣本，建構2008年至2024年之平衡型追蹤資料，探討乾旱風險對企業財務績效（ROA）與股權資金成本（COE）的影響。為更宏觀且有效地界定乾旱事件，本文創新地採用遙感技術擷取乾旱嚴重程度指標，並引入兩項指標：代表水文乾旱的六個月標準化降水指數（SPI-6）與新興的農業乾旱指標Surface Water Availability-Temperature Index（SWATI）。
實證結果顯示，乾旱程度愈高，整體企業的財務績效呈現下降趨勢，惟不同產業間之影響方向不盡相同，部分產業反而受益。此外，當企業受乾旱嚴重影響的工廠占比愈高時，其ROA反而提升，此結果與既有文獻多有出入。針對資本市場反應，研究亦發現COE對當期乾旱呈現負向反應，但在乾旱滯後一期時則轉為正向影響，顯示投資人多半不會即時反應災害事件。進一步分析亦指出，企業財務表現首先受到SPI-6指標的影響，進而再受到滯後一期SWATI指標的作用；相對地，投資人對SWATI的反應則更為即時，顯示企業與利害關係人對不同類型乾旱的反應機制與速度並不一致。
綜合上述，本研究實證了新興綜合型乾旱指標SWATI在財務研究中的應用潛力，並首創結合遙測技術與上市公司追蹤資料，深入探討乾旱風險對企業經營績效及投資人風險認知之影響，對企業風險管理與永續策略具重要參考價值。
;Water resources are a crucial factor in business operations. However, with the intensification of climate change, the frequency of extreme droughts and heavy rainfall events has increased, making water resource management an increasingly significant issue for businesses and stakeholders. In Taiwan, although the annual average precipitation is 2.6 times the global average, the proportion of available water resources is low owing to geographical and climatic limitations, resulting in a highly unstable water resource situation and further increasing uncertainty and risk in industrial operations.
This study used a sample of 498 listed companies in Taiwan and constructed a balanced panel dataset from 2008 to 2024 to examine the impact of drought risk on corporate financial performance (ROA) and the cost of equity capital (COE). To define drought events in a more comprehensive and effective manner, this study innovatively employed remote sensing technology to delineate drought conditions, introducing two indices: the six-month Standardized Precipitation Index (SPI-6) for hydrological drought and the emerging Surface Water Availability-Temperature Index (SWATI) for agricultural drought.
Empirical results showed that the higher the severity of drought, the lower the overall financial performance of companies. However, the direction of the impact varied across industries, with some industries benefiting. Additionally, when a higher proportion of a company’s factories were affected by exceptional drought, its ROA increased, which deviated from existing literature. Regarding capital market reactions, the study also found that COE responded negatively to current drought but turned positive in the period following the drought, indicating that investors generally did not react immediately to natural disaster events. Further analysis revealed that corporate financial performance was primarily influenced by the SPI-6, followed by the lagged SWATI. In contrast, investor reactions to SWATI were more immediate, suggesting that businesses and stakeholders responded at different speeds and mechanisms to various drought types.
In conclusion, this study empirically demonstrated the potential application of the emerging composite drought index SWATI in financial research and pioneers the integration of remote sensing with listed company panel data to explore the impact of drought risk on corporate performance and investor risk perception. These findings offer valuable insights into corporate risk management and sustainability strategies. |
