斷點迴歸方法論之法人持股與企業租稅規避

INSTITUTIONAL OWNERSHIP AND TAX AVOIDANCE：EVIDENCE FROM REGRESSION DISCONTINUITY

本研究採用Fuzzy不連續斷點迴歸模型（fuzzy regression discontinuity design）與工具變數法（instrumental variable method），以兩階段方式探討法人持股比率對企業租稅規避的影響。本研究採用2007年至2016年的台灣50與中型100指數成分股名單的上市櫃公司（排除TDR、F股）共1142個觀察值，進行實證分析。實證結果顯示，首先，指數股票型基金重組，使得台灣中型100指數頂部企業的法人持股比率高於台灣50指數底部企業；其次，兩種指數股票型基金在門檻附近的法人持股比率差異，與企業租稅規避呈顯著正向關係。亦即在門檻值附近，法人持股比率較高的企業的租稅規避程度亦較激進。敏感性分析，採用全體上市櫃企業樣本，18個月衡量基金重組後企業租稅規避程度，運用Crane et al.（2016）的兩階段分析架構，以及分別檢視三大法人，以及不同季審核成分股重組股票基金，獲得一致結果。

We implement a fuzzy regression discontinuity design and instrumental variable methodto examine the effect of institutional ownership on tax avoidance. In this study, ourinitial data are obtained from the Taiwan Economic Journal (TEJ) database. The empiricalresults indicate that, first, the firms at the top of 0051 exhibit much higher institutionalownership than firms at the bottom of 0050. Second, we found a significant, positiverelationship between the differences in the institutional ownership near the thresholds ofthe two indices (0050 and 0051) and tax avoidance. In other words, we find a significantdiscontinuity in the level of the tax avoidance characteristics at the cutoff. The firms withmore institutional investors exhibit higher levels of tax avoidance. By further conducting asensitivity analysis, we used a sample of all listed companies to measure tax avoidance overan 18 months’ period, and adopt the two-stage empirical structure of Crane et al. (2016).Furthermore, we review the three major institutional investors separately, and examineconstituent stock restructuring equity funds in different quarters, all with consistent results.