營利事業所得稅有效稅率對公司內部所得分配之影響

Abstract

台灣在2010年所實施的稅制改革中，通過了產業創新條例以取代2009年底落日的促進產業升級條例，並將營利事業所得稅法定稅率從25%調降至17%。本研究將以2010年的稅制改革為例，探討領取公司頂端百分之十所得者之收入，占全公司所得比率的變化。本文結合了個人層面之所得資料，與所屬公司進行配對，再以公司層面分析所得分配的變動情形。為避免稅率與公司決策行為有相互影響的內生性問題，本研究製作了合成有效稅率，以該工具變數進行兩階段最小平方估計。結果發現，營所稅稅率的下降，會使得領取公司內部頂端百分之十所得比率上升，並且上升部分大多是來自於股利與未分配盈餘的增加，薪資部分則沒有顯著的影響。除此之外，相較於許多文獻對於高所得族群之研究，本文更額外檢視了在公司內部其他90%的所得領取者，更深入分析降稅對公司內部其他所得階層的影響。故2010年營利事業所得稅的調降，雖然改善了租稅優惠集中於特定產業之情形，並使整體企業皆能享受降稅的福利，但同時也可能造成所得分配更加不均，以及營所稅與綜所稅差距過大導致公司分配盈餘誘因減少之問題。

In the tax reform implemented of the year 2010, Taiwan passed the Statue for Industrial Innovation to replace the sunset clause, Statue for Upgrading Industries at the end of 2009, and reduced the corporate income tax rate from 25% to 17%. This study will take the 2010 tax reform as an example to explore the change of income ratio of the top ten percent of companies. This paper combines the personal data, paired with the company, and then analyzes the changes in the distribution at the company level. In order to avoid endogenous problems, this study produces a synthetic effective tax rate, which is the instrumental variable to use two-stage least squares method. Our finding indicates that the decline in the corporate income tax rate would increase the income ratio of the top 10% of companies, and this increase was mostly from the ratio of dividends and retained earnings. There is no significant effect with the ratio of salary. In addition, compared with many literatures on the study of high-income groups, this study examines the other 90% of the recipients in the company, further analyzing the impact of tax reduction on them. Therefore, the reduction of the corporate income tax in 2010 has improved the taxation deduction in specific industries and enabled the whole company to get the benefits of tax reduction, but it may also result in income inequality, and the excessive gap between the corporate income tax and the individual income tax , which has led to the reduction of the company`s distribution of earnings.