本文探討會計師事務所專業中一直較少被文獻討論，然而在實務經營卻極為重要的業務多樣化策略與其財務績效間之闗係。經以台灣財政部發行之1995-2002年的合夥型會計師事務所資料進行分析，主要結果有以下兩項。首先，會計師事務所之業務多樣化程度與其財務績效間，因為規模報酬狀況之差異，而呈非線性之倒U型關係，亦即會計師事務所處在規模報酬遞增 (減) 的狀態時，其業務多樣化程度愈高則呈現財務績效愈高 (低)。此一結果隱含業務多樣化程度有最適點之存在，專業服務業之實證結果亦類似於全球經濟體系中各產業之實證結果，即相關性業務多樣化程度與企業績效之非線性關係。其次，由於本文之實證樣本納入規模較小之合夥型會計師事務所，故實證結果自然地延伸了相關文獻指出業務多樣化愈均衡時，其財務績效愈高之理論預期，進一步發現到較小 (大) 規模會計師事務所，其業務多樣化程度較不均衡 (均衡)，且財務績效較差 (佳) 之不對稱的關係。前二者之實證結果可供會計師事務所之管理階層加以參考。

This article discusses the relationship between business diversification strategies and financial performance, which is rarely discusses in professional documents, but has been the most important component among actual practical managements in the partnership accounting firm area. The data of partnership accounting service firm from 1995 to 2002 had been analyzed by the Taiwan Ministry of Finance; there are approximately two main results from this analysis. First, due to the difference of the returns to scale condition, the relation between the diversification of accounting firms and its financial performance is shown as a non-linear, inverse U shape graph. When firms are under the condition of increasing (decreasing) returns to scale, the higher (lower) level of business diversification, the higher (lower) financial performance they will experience. This result indicates that there is a most suitable spot in business diversification; the result of specialized service industry is also similar to the experimental result of the global economic system in various industries, which shows a non-linear relation between service diversification and enterprise performance. Second, since the real diagnosis of this article integrates the sample of small partnership accounting firms, the result naturally extends the correlation and theory that financial performance will be higher when the business diversification is more balanced, which further discover that the smaller (bigger) scale of the accounting firms, their business diversification will be more imbalanced (balanced), that financial performance will reflect badly (better) as asymmetrical relations. The diagnosis results of the above may supply as references to the management class of accounting firms.

目  錄
第壹章 緒論	1
第一節 研究背景與動機	1
第二節 研究目的	3
第三節 論文結構與研究流程	4
第貳章 文獻回顧	6
第一節 會計師事務所之業務項目	6
第二節 多角化	11
第三節 多角化與績效評估之關聯性	16
第四節 會計師事務所績效	21
第五節 效率基本概念	22
第參章 研究方法	25
第一節 研究假設	25
第二節 研究架構	27
第三節 迴歸模型	27
第四節 變數定義	29
第五節 資料來源	33
第肆章 實證結果	34
第一節 敘述性統計分析	34
第二節 實證分析	47
第三節 敏感性分析	49
第四節 管理意涵討論	54
第伍章 結論、研究限制與建議	55
第一節 結論	55
第二節 研究限制	56
第二節 未來研究建議	56
附錄	57
參考文獻	62

表目錄
表3-4-1 控制變數定義表	31
表4-1-1 投入產出變數敘述統計彙總表	40
表4-1-2 投入產出變數之Pearson及Spearman相關係數彙總表	41
表4-1-3 各變數敘述統計彙總表	43
表4-1-2 主要變數之Pearson及 Spearman相關係數彙總表	44
表4-2-1 迴歸分析彙總表	49
表4-3-1 迴歸分析彙總表	53
表A-1  合夥型會計師事務所各項業務金額與比例彙總表- 1995年	57
表A-2  合夥型會計師事務所各項業務金額與比例彙總表- 1996年	57
表A-3  合夥型會計師事務所各項業務金額與比例彙總表- 1997年	58
表A-4  合夥型會計師事務所各項業務金額與比例彙總表- 1998年	59
表A-5  合夥型會計師事務所各項業務金額與比例彙總表- 1999年	59
表A-6  合夥型會計師事務所各項業務金額與比例彙總表- 2000年	60
表A-7  合夥型會計師事務所各項業務金額與比例彙總表- 2001年	60
表A-8  合夥型會計師事務所各項業務金額與比例彙總表- 2002年	61

圖目錄
圖1-3-1  研究流程	5
圖3-2-1  研究架構	27
圖3-4-1  計算規模報酬之投入產出結構圖	31
圖4-1-1  財務簽證、稅務相關服務、管顧等主要業務結構趨勢圖(金額)	
整體合夥型會計師事務所	36
圖4-1-2  財務簽證、稅務相關服務、管顧等主要業務結構趨勢圖(比例)	
整體合夥型會計師事務所	36
圖4-1-3  財務簽證、稅務相關服務、管顧等主要業務結構趨勢圖(金額)	
規模報酬遞增型會計師事務所	37
圖4-1-4  財務簽證、稅務相關服務、管顧等主要業務結構趨勢圖(比例)	
規模報酬遞增型會計師事務所	37
圖4-1-5  財務簽證、稅務相關服務、管顧等主要業務結構趨勢圖(金額)	
最適規模報酬型會計師事務所	38
圖4-1-6  財務簽證、稅務相關服務、管顧等主要業務結構趨勢圖(比例)	
最適規模報酬型會計師事務所	38
圖4-1-7  財務簽證、稅務相關服務、管顧等主要業務結構趨勢圖(金額)	
規模報酬遞減型會計師事務所	39
圖4-1-8  財務簽證、稅務相關服務、管顧等主要業務結構趨勢圖(比例)	
規模報酬遞減型會計師事務所	39
圖4-1-9  合夥整體業務多樣化與財務績效之十分位數關聯圖	45
圖4-1-10 規模報酬遞增之業務多樣化與財務績效之十分位數關聯圖	46
圖4-1-11 規模報酬遞減之業務多樣化與財務績效之十分位數關聯圖	46
圖4-3-1  規模報酬遞減之業務多樣化與財務績效之十分位數關聯圖	51
圖4-3-2  規模報酬遞減之業務多樣化與財務績效之十分位數關聯圖	51
圖4-3-3  規模報酬遞減之業務多樣化與財務績效之十分位數關聯圖	52
圖4-3-4  會計師事務所業務比例結構圖	54
圖A-1   會計師事務所業務結構趨勢圖 (1995 - 2002) -金額	57

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