2017年美國稅改之折舊優惠對公司資本支出之影響

Abstract

本研究旨在探討 2017 年美國稅改之折舊優惠對公司資本支出之影響。美國於2017 年開始實施《減稅及工作法案》（The Tax Cuts and Jobs Act），其中一項重大的政策改變，即為企業得於取得並使用短期合格資產的年度，選擇是否將該資產之紅利折舊百分之百費用化。本研究為瞭解企業是否因此項政策而確實增加資本支出，遂進行各項研究以探究之。 本研究之研究樣本為西元 2015 年至2018 年美國Compustat 資料庫之所有公司，本研究利用這些樣本，探究在紅利折舊政策實施後，有合格資本支出之公司，相較於無合格資本支出之公司，其資本支出是否有顯著增加。 本研究主要利用傾向評分匹配配對樣本後，透過「差異中之差異估計法」進行迴歸測試，實證結果顯示，受紅利折舊政策影響而有合格資本支出之公司，相較於無合格資本支出之公司，其資本支出顯著增加；本研究亦發現，在紅利折舊政策實施後，風險容忍程度較低及融資受限狀況較低之公司，對於其資本支出之影響會較為顯著；此外，本研究亦進行安慰劑測試及額外測試，以強化原本的實證結果。 本研究證實在新的紅利折舊政策實施後，有合格資本支出之公司會投入較多的資本支出，故此折舊優惠政策確實有效，可供政府於未來制定相關政策時，參考使用。

This study examines the effect of the depreciation breaks on corporate capital expenditure under the 2017 Tax Cuts and Jobs Act (TCJA). One of the significant changes enforce by the TCJA made is the bonus depreciation policy. The TCJA provides a higher bonus depreciation ratio for firms to depreciate their eligible properties acquired and placed into service. Therefore, if this policy is effecitve, the TCJA should encourage companies to invest more capital expenditures. Using a sample between 2015 and 2018, the study matches the sample by propensity score matching. A difference-in-differences analysis indicates that a firm with an investment of qualified assets has significantly more capital expenditures by exploiting the 2017 TCJA’s bonus depreciation policy. Additonally, this study also finds that the results are stronger for firms with lower tolerance of risk and lower financial constraint. The results remain robust to placebo test checks and additional tests. Overall, this study shows that a firm with an investment of qualified assets has more capital expenditure after the TCJA. It demonstrates that the TCJA works effectively in enlarging corporate capital expenditures. The findings should be helpful for the government in setting a new policy.