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主題:業務多樣化策略與其財務績效間之關係。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，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，業務多樣化程度愈高，則財務績效愈高(低)。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，而實證結果也符合業務多樣化愈均衡時，其財務績效愈高之理論預期；亦即，不論規模大小的會計師事務所，其業務多樣化程度愈均衡，財務績效較佳的現象。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。 For professional service firms, empirical researchers have given very little discussion between services diversification and management performance. In order to fill up the gap of literatures, this sample of this study adopted from 1995 to 2002 eight yearly Annual Report of Accounting Firms surveyed by the Ministry of Finance of R.O.C. and tried to find the effect of services diversification on management
performance. Empirical results indicate that : First, due to the difference of the returns to scale condition, the relationship between the diversification of accounting firms and its financial performance is shown as a non-linear, upside down U shape graph.
Namely, when firms are under the condition of increasing (decreasing) returns to scale, the higher (lower) level of business diversification was, the higher (lower) financial performance was. Second, since this study brings into the sample of small partnership accounting firms, the result is consistent with the previous theory that financial performance will be higher when the business diversification is more balanced. In the meanwhile, no matter the size of scale of the accounting firms, their business diversification will be more balanced, that financial performance will be better. The results of the above may supply as references to the management of accounting firms.