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		| Susumu  Cato | 
	
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		| ''Mixed oligopoly, productive efficiency, and spillover'' | 
	
		| ( 2008, Vol. 12 No.33 ) | 
	
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		| The purpose of this paper is to examine the public sector's cost-reducing investment when there exists the effect of R&D spillover. We show that the investment in the mixed oligopoly is not higher than that in the public monopoly. When the cost-reducing effect of investment for each firm is the same, the investment in the mixed oligopoly is equal to that in the public monopoly. In such a case, the emergence of private firms has a positive impact on social welfare. Our model is an extended version of Nishimori and Ogawa (2002), which study the R&D investment by the public sector. | 
	
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		| Keywords: state-owned public firm | 
	
		| JEL: L3 - Nonprofit Organizations and Public Enterprise: General 
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		| | Manuscript Received : Dec 03 2008 |  | Manuscript Accepted : Dec 08 2008 | 
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