營利事業所得稅調降對投資人參與除權與除息決策之影響

The Impacts of Corporate Income Tax Rate Reduction on Investors' Ex-right and Ex-dividend Decisions

陳拓榮(Tuo-Rong Chen)

指導教授 ： 張仲岳

國立臺北大學/商學院/會計學系/碩士(2012年)

摘要

營利事業所得稅稅率自民國九十九年度由25%調降為17%，使股東稅額扣抵比率下降，造成投資人應自行繳納之股利所得稅增加。另一方面，雖然對參與除權息之國外投資人之股利所得稅有降稅效果，卻也造成外資股利扣繳稅額較未調降年度增加。因此本研究之主要目的在探討營利事業所得稅調降，是否使投資人參與除權息之意願降低？
本研究使用t檢定、變異數分析及多元迴歸模型分析，來探討營利事業所得稅調降對除權息前後累積異常報酬率之影響。研究對象為民國98年至100年間分配盈餘的國內上市公司，並排除行業性質特殊之金融業，實證結果如下：

1.營利事業所得稅調降後，除權息前後之累積異常報酬率均較未調降年度低，即投資人在除權息前有賣出股票之行為，但除權息後則無回補股票之情形。

2.營利事業所得稅調降後，僑外股東持股比率與除權息前累積異常報酬率呈負相關，雖然結果並不顯著，但其差異數(D*PERCENT)與調降前相比，有顯著下降。表示在其他條件不變之下，僑外股東持股比率愈高，投資人在除權息前易出現棄權棄息的情形，以規避租稅負擔。

3.營利事業所得稅調降後，僑外股東持股比率與除權息後之累積異常報酬率呈顯著正相關，且其差異數(D*PERCENT)與調降前相比，有顯著上升，此結果符合本文之研究假說，即僑外股東可能選擇在除權息後買進股票，進而造成除權息後的股價異常波動。

關鍵字

營利事業所得稅 ； 除權 ； 除息 ； 累積異常報酬率

並列摘要

The corporate income tax rate was reduced from 25% to 17% in 2010. This research aims to find out if the reduction of corporate income tax lowers the willingness of the investors to participate in ex-dividend or ex-right.
In order to analyze the impacts, the t test, ANOVA, and multiple regression analysis are used in this research. The data are collected from the domestic listed companies which had distributed their earnings from 2009 to 2011. The companies of financial industry are excluded from the sample. The results in this paper are summarized as follows:

1. There is lower CAR (Cumulative Abnormal Returns) of the day before and after ex-dividend date and ex-right date after the corporate income tax rate was reduced. It indicates the investors sold the stocks before ex-dividend date or ex-right date and would not buy back after that day.

2. After the reduction of corporate income tax rate, there was a negative correlation in foreign ownership ratio of the company and it’s CAR before ex-dividend or ex-right date. Although the result is not significant but the coefficient (D * Percent) is significant lower than before the rate reduction. Other things being equal, it suggests the higher the foreign ownership ratio, the more likely for the investors to abandon participating in the ex-dividend or ex-right to avoid the tax payment.

3. After the reduction of tax rate, there was a significantly positive correlation in foreign ownership ratio and CAR after the ex-dividend or ex-right date. And the coefficient (D * Percent) had a significant increase. This result is consistent with the null hypothesis that the abnormal stock price volatility after the ex-dividend or ex-right date is caused by foreign shareholders who might repurchase stocks after the ex-dividend or ex-right date.

並列關鍵字

Corporate income tax ； ex-right ； ex-dividend ； cumulative abnormal returns

參考文獻

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