臺灣實施20年的〈促進產業升級條例〉於2009年底屆滿，政府已將相關租稅減免多予取消，且一併進行所得稅制改革，其內容包括稅率與扣除額等的調整，除影響企業經營外，更關係到家計稅負輕重與社會公平正義，在所得分配日趨惡化的臺灣，值得深入評析。本文首先透過稅制改革前2009年〈統計專冊〉資料分析得知:（1）綜所稅之合法租稅減免浮濫，造成課稅所得之稅基嚴重侵蝕，且非法逃漏稅普遍存在；（2）各種扣除額因執行問題，形成「累進享用」的不合理現象；（3）享有稅額扣抵的股利所得，高度集中在最富有階層。本文據此規劃不同改革方案，並以2011年所得稅報稅資料進行實證分析，主要結果發現：（1）綜所稅稅率的調降，在累進稅率下，多使得高所得者獲得較大的減稅實益，反而不利於家計稅負分配的公平性；（2）高所得階層實際享有教育學費特別扣除額與殘障特別扣除額的比率過高，故提高此兩項扣除額，會使得全體社會之稅負分配惡化，與一般認知能改善租稅公平有相當大的差異；（3）標準扣除額的調高，因僅能讓中低所得者享受減稅實益，故不但政府稅收損失相對較少，且可改善社會稅負分配的公平性；（4）股利所得的租稅處理若改為27萬元限額兔稅法，將使全體社會之稅負分配明顯改善，且可增加政府稅收。

In Taiwan, the tax deductions and allowances saved following the expiry of the Statute for Upgrading Industries on December 31, 2009 have generated additional revenues for reforming the personal income tax system. Aside from the effects on business operations and industrial development, the impact on household tax-burden and income distribution requires careful consideration in the context of Taiwan's worsening income inequality. Based on personal income tax return data collected by the Ministry of Finance, our analysis leads to the following results. First, according to our progressive tax system, lowering the personal income tax rates tends to benefit the rich more than the poor and is thus harmful to household tax equity. Second, since the rates for the special deductions in regard to education and the physically and mentally challenged are high for the high income group, increasing their deduction rates will hurt overall tax equity. Third, raising the standard deduction can benefit the middle and lower income groups more, by not only improving the tax-burden distribution but also minimizing the loss in tax revenues. Finally, since dividend income is highly concentrated in the top decile, if the tax treatment were modified and the income deduction method adopted, income distribution would improve significantly and tax revenue would increase.