美國減稅與就業法案對企業會計穩健性之影響

Abstract

美國於2017年通過減稅與就業法案（Tax Cuts and Jobs Act of 2017, TCJA），其中一項修法內容為限制利息費用可用來扣抵稅的數額。在法案通過後，由於利息費用抵稅的效果減弱，於過去文獻中證實對扣抵數額增加了限制後，受影響公司將降低其槓桿率。另外，大多文獻也支持債務比率和會計穩健性之正向關聯性，因此，本研究欲進一步探討，是否TCJA通過後，受影響公司將降低其會計穩健性程度，並以2014年至2021年於美國境內成立之公司做為樣本進行迴歸測試。 實證結果顯示，TCJA通過後，由於對利息費用扣抵數額增加了限制，導致受影響公司降低其槓桿率，進而使會計穩健性程度下降，減少其認列損失的不對稱及時性。另外，本研究也發現平均槓桿程度較高的企業，受到利息費用扣抵限額的影響越大，在TCJA通過後，會計穩健性程度降低的情況更為明顯。最後本研究也利用不同的實驗組定義及會計穩健性衡量模型進行敏感性分析，結果同樣證實本研究的假說結果。

The United States enacted the Tax Cuts and Jobs Act of 2017 (TCJA), which placed limitations on the deduction of interest expense for tax purposes. Due to the reduced tax benefits of interest expenses, previous studies have shown that affected companies significantly decrease their leverage levels. Several prior studies have supported a positive relationship between leverage and accounting conservatism. To provide a causal inference for the effect of leverage on accounting conservatism, this study investigates whether affected companies decreased accounting conservatism after the passage of the TCJA. Using a Difference-in-Difference (DID) design and the sample in the United States from 2014 to 2021, the empirical results in this study indicate that after the TCJA was passed and the limitations on the deductibility of interest expenses were implemented, affected companies decreased accounting conservatism and the timeliness of recognizing economic losses. Furthermore, this study finds that companies with higher leverage were more affected by the limitations on interest expense deductions. Specifically, this study finds that after the passage of the TCJA, the decrease in the level of accounting conservatism was more pronounced in these companies. Finally, the study conducts sensitivity analyses by defining the treatment sample differently and adopting another model to measure accounting conservatism, and the results consistently supported the hypotheses of this research.