本研究是利用Zellner (1962)的近似無關迴歸估計法估計多產品超越對數成本函數及其所對應之要素份額方程式所構成的聯立模型，以探討台灣會計師事務所是否具有規模經濟與多樣化經濟。實證結果發現，會計師事務所所提供之財務簽證、稅務服務及其他服務等業務均具有產品別規模經濟；射線規模經濟亦顯著地存在，此隱含會計師事務所享有規模經濟利得，亦即平均成本會隨產出之增加而有逐漸下降的趨勢；會計師事務所在提供財務簽證與稅務服務兩項業務、稅務服務與其他服務兩項業務皆具有多樣化經濟。至於財務簽證與其他服務兩種業務間之組合，則不具有弱成本互補性，因此，多樣化經濟可能不存在。
本研究建議，會計師事務所可採取合併或購併方式來擴大其經營規模，降低因未在最適規模生產所帶來之成本不利影響。當然，這些事務所所購併或合併的對象最好是以經營財務簽證與稅務服務或稅務服務與其他服務為主者，以進一步享受多樣化經濟利得。另外，本研究亦建議中小型會計師事務所以加強具有成本互補性，同時兼營稅務服務與其他服務之業務為主，而大型會計師事務所則以加強財務簽證與稅務服務之業務為主，以享受多樣化經濟之好處。若會計師事務所有經營管理顧問業務者，為避免因財務簽證與其他服務兩種業務間不具弱成本互補性，應另成立管理顧問公司以專業化經營。

1.王國樑、余威廷(1995)，「台灣證券業規模與多樣化經濟之探討」，證券市場發展季刊7(3)，頁125-145。
2.王國樑、翁志強(1996)，「台灣地區旅行業規模與多樣化經濟之探討」，臺大管理論叢7(1)，頁85-104。
3.王國樑(1996)，「多樣化經濟實證方法再探討：以台灣旅行業為例」，中國統計學報34(2)，頁97-114。
4.李佳蓉(2002)，「台灣國際觀光旅館規模與多樣化經濟之探討」，政治大學經濟學系碩士論文。
5.呂麗慧(1990)，「台灣地區公民營銀行生產力之比較」，東吳大學經濟研究所碩士論文。
6.呂秋玉(1992)，「多元化產出之金融機構規模經濟與範圍經濟-台灣地區信用合作社之個案研究」，合作經濟33期，頁24-41。
7.沈中華(1986)，「台灣地區中小企業銀行成本函數之研究」，臺灣大學經濟研究所碩士論文。
8.林基煌(1992)，「我國證券商經濟規模之研究 - 民國七十九年之實證分析」，國立政治大學學報65期，頁305-350。
9.桂勝嘉(1988)，「台灣地區銀行體系規模經濟之研究」，淡江大學金融研究所碩士論文。
10.翁志強(1998)，「台灣會計師事務所規模與多樣化經濟、效率及獲利能力之探討」，政治大學經濟學系博士論文。
11.財政部統計處(1994-2003)，「會計師事務所服務業調查報告」。
12.財政部證券暨期貨管理委員會網站(http://www.sfc.gov.tw)。
13.張鐵軍、徐中琦(1993)，「台灣地區本國銀行規模經濟與範圍經濟之實證研究」臺灣銀行季刊44(1)，頁32-57。
14.張寶光、楊忠城、陳燕錫( 2003)，「新經濟環境下我國會計師產業人力資源替代彈性演變之研究」，第四屈全國實證經濟研討會。
15.張寶光、楊忠城、陳燕錫( 2003)，「台灣會計師事務所績效決定因素之探討：以中、大型事務所為例」，第四屈全國實證經濟研討會。
16.黃台心(1998)，「以隨機成本邊界函數分析本國銀行的規模與多元經濟」，經濟論文叢刊26(2)，頁209-241。
17.蔡培玄、黃敏助(1986)，「信用合作社規模經濟問題之研究」，基層金融，民國七十五年九月，頁129-163。
18.劉錦龍、王汝振(1987)，「台灣地區信用合作社的規模經濟與多元生產經濟」，台灣經濟，民國七十六年二月，頁39-47。
19.Barten, A. P. (1969), “Maximum Likelihood Estimation of a Complete System of Demand Equations,” European Economic Review, 1, 7-73.
20.Baumol, W. J., J. C. Panzar, and R. D. Willig (1982), Contestable Markets and the Theory of Industry Structure , New York:Harcourt Brace Jovanovich.
21.Behn, B., J. V. Carcello, D. R. Hermanson, and R. H. Hermanson (1997), “The Determinants of Audit Client Satisfaction Among Clients of Big 6 Firms,” Accounting Horizons, 11, 7-24.
22.Berger, A. N., G. A. Hanweck, and D. B. Humphrey (1987), “Competitive Viability in Banking: Scale, Scope, and Product Mix Economies,” Journal of Monetary Economies, 20, 501-520.
23.Brown, R. S., D. W. Caves, and L. R. Christensen (1979), “Modelling the Structure of Cost and Production for Multiproduct Firms,” Southern Economic Journal, 256-273.
24.Bullen, M. L., and E. G. Flamholtz (1985), “A Theoretical and Empirical Investigation of Job Satisfaction and Intended Turnover in the Large CPA Firm,” Accounting, Organizations and Society, 10, 287-302.
25.Caves, D. W., and L. R. Christensen (1980), “Global Properties of Flexible Functional Forms,” American Economic Review, 70, 422-432.
26.Chesser, D. L., and C. W. Moore (1996), “The CPA-financial Planner: Some Insights,” CPA Journal, 66, 40-43.
27.Christensen, L. R., D. W. Jorgenson, and L. J. Lau (1973), “Transcendental Logarithmic Production Frontiers,” The Review of Economics and Statistics, 55, 28-45.
28.Din, M. U., E. Ghani and S. K. Qureshi (1996), “Scale and Scope Economies in Banking: A case Study of the Agriculture Development Bank of Pakistan ,” The Pakistan Development Review, 35(3), 203-213.
29.Dopuch, N., and M. Gupta (1997), “Estimation of Benchmark Performance Standards: An Application to Public School Expenditures,” Journal of Accounting and Economics, 23, 141-161.
30.Egan, M. E. (1985), “CPA Firm Turnover: Problems and Solutions,” Ohio CPA Journal, 44, 11-13.
31.Fields, J. A., and N. B. Murphy (1989), “An analysis of Efficiency in the Delivery of Financial Service: The Case of Life Insurance Agencies,” Working Paper, Department of Finance, University of Connecticut, CT. 12
32.Gallant, A. R., and D. W. Jorgenson (1979), “Statistical Inference for a System of Simultaneous, Nonlinear Implicit Equations in the Contex of Instrumental Variable Estimation,” Journal of Econometrics 11,275-302.
33.Gerrard, I., K. Houghton, and D. Woodliff (1994), “Audit Fees: The Effects of Auditee, Auditor and Industry Differences,” Managerial Auditing Journal, 9, 3-11.
34.Gilligan, T., M. Smirlock and W. Marshall (1984), “Scale and Scope Economies in the Multi-Product Banking Firm,” Journal of Monetary Economies, 13, 393-405.
35.Glazer, A. S., and S. L. Fabian (1997), “Best Practices for CPA Firms,” Journal of Accountancy, 184, 93-98.
36.Goldberg, L. G., G. A. Hanweck, M. Keenan and A. Young (1991), “Economies of Scale and Scope in the Securities Industry,” Journal of Banking and Finance, 15, 91-107.
37.Goldstein, S.J., J. E. Mcnulty and J. A. Verbrugge (1987), “Scale Economies in the Savings and loan Industry before Deregulation,” Journal of Economics and Business, 39, 199-207.
38.Hall, R. E. (1973), “The Specification of Technology with Several Kinds of Output,” Journal of Political Economy.
39.Hardwick, P. (1994), “Scale and Scope Economies in the UK Life Assurance Industry,” British Review of Economic Issue, 16(40), 69-85.
40.Kim, H. Y. (1986), “Economies of Scale and Economies of Scope in Multiproduct Financial Institutions: Further Evidence from Credit Union,” Journal of Money, Credit and Banking, 18,220-226.
41.Kmenta, J., and R. F. Gilbert (1968), “Small Sample Properties of Alternative Estimators of Seemingly Unrelated Regressions,” Journal of the American Statistical Association, 63, 1180-1200.
42.Koreto, R. J. (1997), “Bill Gates’ Win-Win Scenario for CPAs,” Journal of Accountancy, 183, 59-61.
43.Lau, L. J. (1974), “Applications of duality theory: comments,” Frontiers of Quantitative Economics, 2, 176-199.
44.Lewandowski, N. J. (1986), “Marketing Ourselves and Our Services to Existing Clients,” Ohio CPA Journal, 45, 36-38.
45.Mester, L. J. (1987), “A multiproduct cost study of savings and loans,” Journal of Finance, 42, 423-445.
46.Murray, J. D., and R. W. White (1983), “Economies of Scale and Economies of Scope in Multiproduct Financial Institutions: A Study of British Columbia Credit Unions,” The Journal of Finance, 38, 887-902.
47.Noulas, A. G., S. C. Ray and S. M. Miller (1990), “Returns to Scale and Input Substitution for Large U.S. Banks,” Journal of Money, Credit and Banking, 22, 94-108.
48.Panzar, J. C., and R. D. Willig (1977), “Free Entry and the Sustainability of Natural Monopoly,” Bell Journal of Economics, 8, 1-22.
49.Pong, C. M., and G. Whittington (1994), “The Determinants of Audit Fees: Some Empirical Models,” Journal of Business Finance and Accounting, 21, 1071-1095.
50.Read, W. J. (1997), “Attracting Top-notch Graduates to Local Firms,” Practical Accountant, 30, 41-45.
51.Shamis, G. S. (1996), “Recruiting the Best and Brightest: A Guide to Local and Regional Firms,” Ohio CPA Journal, 55, 41-42.
52.Shields, D. (1984), “Small CPA Firm Product Differentiation in the Small Business Market,” Accounting, Organizations and Society, 9, 61-80.
53.Talwar, A. K. (1986), “Profit Allocation in CPA Firm Partnership Agreements,” Journal of Accountancy, 161, 91-95.
54.Ward, D. D, R. J. Elder, and S. C. Kattelus (1994), “Further Evidence on the Determinants of Municipal Audit Fees,” Accounting Review, 69, 399-411.
55.Wilks, S. S. (1962), Mathematical Statistics, John Wiley & Sons, New York.
56.Zellner, A. (1962), “An Efficient Method of Estimating Seeming Unrelated Regressions and Tests of Aggregation Bias,” Journal of the American Statistical Association, 57, 348-368