企業租稅規劃對權益資金成本之影響─兼論公司治理之角色

本研究以台灣上市公司為研究對象，樣本期間為1991年至2013年，主要探究企業特質對避稅行為之影響，並進一步分析企業在長期施行避稅行為下是否因此會提高權益資金成本，反而適得其害。最後，再加入外部監督機制，檢視能否減輕激進式避稅行為對企業資金成本之傷害。結果發現:⑴企業平均稅率遠低於現行之稅率，此現象可能是企業於虧損扣抵外，尚積極從事避稅行為。⑵另外實證結果發現負債比例低、固定資產比例高、無形資產比例低、公司規模大及投資報酬率低的企業，較容易傾向激進式避稅。(3)企業積極避稅確實將使公司權益資金成本提高而不利於公司，因為理性之投資人了解這些避稅行為可能會增加公司財報的資訊不透明及管理者可能趁機移轉股東財富於自身。(4)外部公司治理無法有效抑制激進式避稅之傷害，而控制權與現金流量權之分離程度卻會提高權益資金成本。

關鍵字

避稅；權益資金成本；公司治理

並列摘要

This study is based on Taiwanese public listing companies between 1991 to 2013. Majority of this study will investigate the influence on corporations due to tax avoidance, analyze if the corporation’s long term tax avoidance will raise cost of equity, and add into external supervise mechanism to examine will mitigate the damage by aggressive tax avoidance. The results show that (1) the phenomenon of average tax rate is lower than current tax rate may cause by the corporation not only do the carryback of losses but also aggressively tax avoidance. (2) the lower liability ratios, higher PPE ratio, lower IA ratio, bigger company size, and lower ROI are tend to aggressive tax avoidance. (3) the tax avoidance will raise the cost of equity. It will be disadvantageous to the company because the rational investors understand those tax avoidance methods may cause corporate financial statements become furtive, and management personal might transfer stockholders’ wealth to his own agenda. (4) external corporate governance is not able to restrain the damage which is cause by aggressive tax avoidance. However, the split-up of control rights and cash flow rights will raise the cost of equity.