我國關係人交易普遍且具重要性，而過去研究顯示關係人交易會對公司產生負面效果，且關係人交易之查核具有困難度，因此本研究以關係人交易較多且查核風險較高之高科技公司為研究對象，將關係人交易分為關係人銷貨交易、關係人進貨交易、關係人應收款與關係人應付款等四項類別，探討關係人交易與審計品質的關係。進一步探討當關係人交易分為發行公司與關係人皆受相同會計師查核與受不同會計師查核兩類型，對發行公司財務報表審計品質的影響。實證結果發現：關係人銷貨交易、關係人進貨交易與審計品質呈負向關係；關係人銷貨交易、關係人進貨交易與關係人應收款兩造受不同會計師查核者，對其發行公司財務報表審計品質之負面影響較兩造受相同會計師查核者強。 / Related party transactions are common and important in Taiwan, and empirical studies in Taiwan show that related party transactions have negative impact on earnings management and company performance. Based on auditing standards and literature, related party transactions are difficult to audit, and high technology firms have more related party transactions which may result in higher audit risk than other industry. Therefore, we investigate the association between related party transactions (including sales to related parties, purchases from related parties, accounts receivable from related parties and payable to related parties) and audit quality (proxied by accrual quality) in high technology firms, and find that sales to related parties and purchases from related parties have negative impact on audit quality. Next, we investigate the impact of related party transactions audited by the same auditor or different auditors. Empirical results show that sales to related parties, purchases from related parties and accounts receivable from related parties audited by different auditors show stronger negative impacts on audit quality than those audited by same auditors.

本研究係探討關係人交易雙方是否委任相同會計師進行查核，對企業負債資金成本之效果。本文以企業利息費用除以平均帶息負債衡量企業之負債資金成本，企業之關係人交易部分則分成關係人銷貨交易、關係人進貨交易、關係人應收款、關係人應付款等四類型交易，來討論關係人交易與企業負債資金成本之關聯，接著將各類型關係人交易再細分成由相同會計師查核關係人交易雙方與由不同會計師查核關係人交易雙方兩類，以檢驗相同會計師查核對於企業負債資金成本之影響。 研究結果發現關係人交易與企業負債資金成本之關聯並無統計上之顯著性。然將關係人交易進一步拆分為是否由相同會計師查核關係人交易雙方後，關係人進貨交易與關係人銷貨交易等兩類型交易若由相同會計師查核交易雙方，其相較於不同會計師查核能夠有效減緩企業負債資金成本增加之情形。 / This study examines the effect of same auditor auditing both sides of related party transactions (RPTs) on cost of debt. In this study, cost of debt is measured using interest expenses divided by average interest bearing debt and we hand collect from annual reports the data of the four common types of RPTs: sales to related parties, purchases from related parties, accounts receivable from related parties and accounts payable to related parties. For the four types, we further split RPTs into RPTs whose involved sides are audited by the same auditor and RPTs whose involved sides are audited by different auditors. We do not find any evidence that RPTs are associated with cost of debt. However, we find that for sales to related parties and purchases from related parties, RPTs whose involved sides are audited by the same auditor are associated with cost of debt less strongly than RPTs whose involved sides are audited by different auditors. Our results suggest that same auditor auditing can mitigated the detrimental effect of RPTs on cost of debt.