美國國稅局稅務查核對公司避稅行為之影響 - 以研發支出及境外收入為例

Abstract

本論文之研究主旨在於探討美國國稅局對具有研發費用及境外收入的跨國企業避稅行為之監督能力。由於現有部份學者認為美國國稅局對跨國企業避稅行為之監督對企業的稅務政策是有所影響的，為進一步瞭解箇中事實，本研究以美國上市櫃公司作為探討標的，且以美國國稅局對各資產組別的抽查機率作為美國國稅局監督之代理變數，並以設置虛擬變數及交乘項之方式，進行美國公司之有效稅率是否因國稅局監督而發生變化之檢驗，文內取用樣本之期間為2004年至2014年；另外，在敏感性分析所得稅應計數時，所取用樣本之期間則為2003年至2013年。由本研究之實證結果發現，美國國稅局對具有研發費用及境外收入的跨國公司確實具有監督能力，且此項監督行為確實能使公司減少避稅行為，公司所得稅應計數品質雖未因此提升，但對研發比重較高的跨國公司言，國稅局的監督效果反而降低，由於無法有效落實監督的結果，反而使跨國公司的避稅行為明顯增加，不過公司所得稅應計數品質卻因而上升。本研究之實證結果可增加社會大眾對國稅局對公司監督的了解。

This study examines the effect of the Internal Revenue Service (IRS) audits on multinational companies with research and development expenditures (R&D). We find that the IRS audits more positively affect multinational R&D companies’ effective tax rate (ETR) compared with other companies’, suggesting that the IRS audits trigger these companies to have less tax avoidance than others. Additionally, we examine the IRS audit impacts on multinational companies’ R&D spending level. We find that the IRS monitoring does not trigger multinational firms with higher R&D scale to have higher ETR. This implies that IRS has more monitoring impact on multinational R&D companies, but the monitoring impacts are negatively related to the companies R&D spending. Surprisingly, after replacing ETR with tax accrual quality, we find that IRS audits trigger multinational R&D companies with higher R&D spending to have higher tax accrual quality. Overall, this study provides some evidence of IRS monitoring on multinational R&D companies’ tax avoidance and tax accrual quality. Hopefully, the evidence could provide implications on companies’ tax planning.