非審計服務公費是否會影響會計師之獨立性進而導致財務報表品質降低，引起學術界諸多推論，而會計師是否會妥協其獨立性係在於聲譽維護與經濟依賴間之取捨；聲譽維護則是指會計師若被察覺其獨立性有失偏頗，聲譽的損害效果也會導致其他客戶不願續而購買審計服務，故會計師會以保護聲譽為其主要考量，進而不輕易妥協獨立性於客戶。經濟效果使得會計師為保有並實現特定客戶之準租而妥協獨立性，該議題主要之爭議在於當非審計服務公費比重過高時，會計師之獨立性容易受到影響，但卻無文獻提出，非審計服務公費佔總公費收入的比重究竟多大時，會對會計師獨立性造成重大性影響，進而造成會計師出具不適當之查核報告意見而影響到投資大眾之權益。
故本研究欲探究會計師於經濟依賴及聲譽維護中如何取捨，是否非審計公費佔總公費收入於一定比重時，會影響查核人員之獨立性，即非審計服務公費佔總公費收入的比重多少時係為會計師決定聲譽維護或是選擇經濟依賴之轉折點。故本研究應用門檻迴歸模型 (Hansen, 1999)，以「非審計公費收入佔總公費收入之比率」為門檻變數探討其結構性轉變，將樣本依門檻變數客觀地將樣本區分為兩大類，並以偵測異常應計項目推測企業進行盈餘管理的程度，並探求非審計服務公費對查核人員獨立性影響之一門檻值，盼於限制會計師事務所之非審計服務闡述另一論點。研究結果指出當非審計公費收入佔總公費收入之比率大於門檻值之樣本公司，會計師的確比較能容忍較多之異常應計項目，而在門檻值之下之樣本公司其擁有較好之審計品質。

This study utilizes a panel threshold regression model to plow two of the most profound issues in auditing: First of all, does economic bonding compromise audit quality, and secondly, does the SOX prohibition of certain nonaudit services mitigate the association between fees and auditor independence? Empirical results suggest that there indeed exists a threshold value which would impair audit quality once nonaudit services surpass it. Moreover, nonaudit fees has yet plummeted subsequent to the prohibition of certain nonaudit services designed to mitigate auditors' economic bonding with their clients, suggesting that the efforts made by authorities have been largely ineffective. The results lead us to ponder whether the fee structure and the existing practice of employing auditors at the discretion of the management should be rigorously reviewed to warrant audit quality.

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