客戶重要性與租稅規避程度間之關聯性

The Association between Client Importance and Tax Avoidance

本研究主旨在以2010年至2016年間之臺灣上市櫃公司，驗證客戶重要性與企業租稅規避的關聯性。為避免單一年度特殊事件影響實證結果，本文分別以三年期有效稅率、當期有效稅率及現金有效稅率衡量企業租稅規避程度，並以企業支付公費占其會計師事務所（或主簽會計師）自所有上市櫃公司收取公費總額之比例，衡量其對會計師事務所（或主簽會計師）之客戶重要性。實證結果顯示，無論以會計師事務所或以主簽會計師為衡量基礎，會計師事務所（主簽會計師）對其受查客戶的經濟依存度愈高，受查客戶有較低的租稅規避程度。 Using Taiwan listing companies from 2010 through 2016 as sample, this study aims to examine the association between client importance and tax avoidance. To ensure that the empirical results are not affected by a single event during a given fiscal year, the degree of tax avoidance is respectively measured by the three-year effective tax rate, the three-year current tax rate, and the three-year cash effective tax rate. In addition, an accounting firm's client importance is measured by the audit fee paid by client in proportion to the aggregate audit fees accounting firms receive from all Taiwan listing companies. Regardless of whether the accounting firm or engagement partner is used as measurement basis, the empirical results indicate that the higher the accounting firms' (the engagement partners') economic dependence on the audit client, the lower the degree of client tax avoidance.