過去的研究對於產品研發具有外溢效果與公營事業民營化前後的效率問題，均有獨立且深入的探討，但結合混合雙占與研發外溢效果的相關研究較少，故本文嘗試探討在公私營廠商並存的架構下，外溢效果的存在與否，如何影響到廠商的研發與產出決策，並進一步探討對社會福利的影響。本文於技術外溢方面參考D'Aspremont and Jacquemin (1988)一文之模型，在公營廠商的目標函數的設定上，則以White (1996)為主要參考依據。
本文主要發現：(一)、當商品可藉由外溢效果(如學習或模仿)來降低生產成本時，公營廠商的存在可提高市場產量與社會福利水準，這是標準的正的生產外部性情境。此時，政府的介入市場有助於矯正市場失靈，從消極意義上說，可避免廠商利用獨大侵占消費者的福利。(二)、政府可以透過補貼公營廠商的研發，促使市場競爭的廠商增進研究水準，達成對於該產業整體研發水準的提升，在完全外溢效果的情境裡將提高社會福利水準，但不具技術外溢的情境裡，補貼則造成社會福利的減少。

With regard to government-owned firm privatization and technology spillovers effect, many papers had investigated before. But the combination of two type of topics, mixed oligopoly and R&D spillover effects ,is unusual.
This paper will show how technology spillovers effects markets including both private and public firms. We apply the model of D’Aspremont and Jacquemin (1998) and reassign the objective function of White (1996).
In this paper, we present two main results. First, when the commodity is easily replicated due to spillover effect, its production cost must lower. The existence of government-owned firms can higher social welfare and market output. Therefore, government intervention can correct market failure. Second, That government subsidize research cost to public firms can encourage firms to proceed to research and develop. But subsidy cause social welfare reduction under no spillover effect situation. On the contrary, subsidy to public firms higher social welfare in spillover effect situation.

第一章 緒論 1
第一節 研究動機與目的 1
第二節 本文架構 2
第二章 文獻回顧 3
第三章 理論模型 7
第一節 模型假設 7
第二節 外溢效果對廠商影響 9
第三節 外溢效果與社會褔利 13
第四章 補貼、市場規模與邊際成本對廠商的影響 20
第一節 政府補貼之比較靜態分析 20
第二節 市場規模之比較靜態分析 24
第三節 邊際成本之比較靜態分析 26
第五章 結論 30
參考文獻 32

謝明振 (2006)，「台灣公營事業民營化之研究」，商學學報，14(1)，187-210。
鄭育仁 (2003)，「國營事業民營化治理與誘因機制之研究」，國立中山大學企業管理學博士論文。
張佳涵 (2007)，「雙佔市場結構下雙重外部性對廠商合作決策及社會福利之影響」，國立高雄大學經濟管理研究所碩士論文。
蔡有光 (2002)，「不對稱複佔下之研發」，國立暨南國際大學經濟學研究所碩士論文。
Barros, F. (1995), “Incentive Schemes as Strategic Variables: An Application to a
Mixed Duopoly,” International Journal of Industrial Organization, 13,
373-386.
Cremer, H., Marchand, M. and Thisse, J.F. (1987), “The Public Firm as an Instrument
for Regulating an Oligopolistic Market,” Oxford Economic Papers, 41,
283-301.
D'Aspremont, C. and Jacquemin, A. (1988), “Cooperative and Noncooperative R&D
in Duopoly with Spillovers,” American Economic Review, 78(5), 1133-1137.
Dixit, A.K. and J.E. Stiglitz (1979), “A model of duopoly suggesting a theory of entry
Barriers,” Bell Journal of Economics, 10(1), 20-32.
De Fraja, G. (1991), “Efficiency and Privatization in Imperfectly Competitive
Industries,” Journal of Industrial Economics, 39, 311-321.
Grossman, G. M. and Helpman, E. (1991), “Trade, Knowledge Spillovers,” European
Economic Review, 35(2, 3), 517-526.
Hinloopen, J. (1997), “Subsidizing Cooperative and Noncooperative R&D in Duopoly
with Spillovers,” Journal of Economics, 66(2), 151-175
Jim Y. Jin and M. Troege (2006), “R&D Competition and Endogenous Spillovers,”
The Manchester School, 74(1), 40-51
Katz, M.L. (1986), “An Analysis of Cooperative Research and Development,” Rand
Journal of Economics, 17, 527-543
Megginson, W. L., Nash, R. C. and van Randenbough, M. (1994), “The Financial and
Operating Performance of Newly Privatized Firms: an International Empirical
Analysis,” Journal of Finance, 49(2), 403-452
Poyago-Theotoky, J. (1999), “A Note on Endogenous Spillovers in a Non-Tournament
R&D Duopoly,” Review of Industrial Organization, 15(1), 253-262
Rajeev K. Goel and S. Haruna (2011), “Cost-Reducing R&D with Spillovers and
Trade,” Journal of Institutional and Theoretical Economics, 167(1), 314-326
Spence, M. (1984), “Cost Reduction, Competition and Industry Performance,”
Econometrica, 52(1), 101-121.
Stepanova, A. and A. Tesoriere (2011), “R&D with Spillovers: Monopoly versus
Noncooperative and Cooperative Duopoly,” The Manchester School, 79(1),
125-144.
Tesoriere A. (2008), “Endogenous R&D Symmetry in Linear Duopoly with One-way
Spillovers,” Journal of Economic Behavior and Organization, 66(1), 213-225
White, D.M. (1996), “Mixed Oligopoly, Privatization and Subsidization,” Economics
Letters, 53, 189-195.