本研究旨在探討2017年臺灣實施「現股當日沖銷交易證交稅減半政策」（簡稱當沖降稅政策）後，對於上市櫃公司股利政策之影響。相較於過往文獻多聚焦於政策對市場流動性、波動性或成交量之影響，本文進一步延伸關注至政策對企業財務決策層面之潛在影響。本研究以2013年至2020年之臺灣非金融類上市櫃公司為樣本，透過差異中的差異法（Difference-in-Differences, DiD）進行實證分析，另透過動態DiD模型與安慰劑檢驗強化研究結論之可信度。實證結果顯示，相較於控制組，受政策影響程度較高之實驗組公司在政策實施後，其現金殖利率顯著上升，且此效果主要來自於股利發放水準之提升，而非股價下跌所致，推測為企業因應當沖降稅政策造成之投資人結構改變，進而調整其股利政策。

This study investigates the impact of Taiwan’s 2017 policy to halve the securities transaction tax on day-trading transaction (hereafter, the "day-trading tax cut policy") on corporate dividend policies. While prior literature has predominantly focused on the policy’s effects on market liquidity, volatility, or trading volume, this paper extends the discussion to its potential influence on corporate financial decisions. Using a sample of Taiwan’s non-financial listed firms from 2013 to 2020, this study employs a Difference-in-Differences (DiD) empirical strategy to estimate the policy’s effect. In addition, dynamic DiD models and placebo tests are applied to strengthen the credibility of the findings. The empirical results indicate that, compared to the control group, firms more exposed to the policy experienced a significant increase in dividend yield after the policy was implemented. Further analysis reveals that this effect primarily stems from higher dividend payouts rather than a decline in stock prices. The findings suggest that companies adjusted their dividend policies in response to investor base changes induced by the tax cut policy.

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沈盈妤（2022），《當日沖銷降稅政策與其延長對於臺股市場交易之影響》，碩士論文，國立政治大學財政學系，臺北市。
李姿瑩（2008），《股票流動性與企業現金股利政策》，碩士論文，國立臺灣大學國際企業學研究所，臺北市。
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