跨国公司在华专利申请对我国的技术外溢效应研究
|
摘要
在经济全球化的今天,一国的技术进步不仅受到国内技术创新的影响,也受国际因素的影响。这种影响在技术创新能力薄弱的发展中国家和地区表现得尤为明显。随着发展中国家和地区知识产权保护制度的不断完善,发达国家在其专利申请的数量和质量都得到明显的提升。这为发展中国家和地区技术创新能力的提高及创新机制的形成提供了潜在的有利条件,发展中国家可以充分利用国外专利申请产生的技术溢出效应,缩小与发达国家的技术差距。国外专利申请作为国际技术扩散的重要路径之一,是否加快了大量先进专利技术信息的转移和扩散,从而对发展中国家和地区产生显著的技术溢出效应,如何利用其促进技术进步备受国内外学者的关注。
本文利用中国27个省市1985年到2006年面板数据,研究了外国公司在华专利申请对我国全要素生产率的影响。实证结果表明,跨国公司在华专利申请对我国技术进步并没有产生直接溢出效应,但可以间接激励我国本土企业加强自主研发,从而促进我国技术进步;从总体效应看,跨国公司在华专利申请负的直接效应抵消了正的间接效应,总体上并没有对我国的全要素生产率产生推动作用。从地区层面看,东部地区由于其经济和地域优势一方面获得较大的外国研发资本存量间接溢出效应,但也由于知识产权的保护受到外国企业较大的直接技术挤压;另外,跨国公司在华专利申请溢出的国外研发资本存量对东、中、西等各地区技术进步的综合影响溢出效应都为负。研究结果同时表明,跨国公司在华专利申请的间接技术溢出效应对社会整体科技水平的提高有积极意义,但目前我国研发投入仍然是我国技术进步的主要“源泉”。
With the globalization of economy,a country's technological progress is not only affected by the domestic technological innovation but also by the international factors. This effect is particularly evident in developing countries and regions whose technological innovation capacity is weak. With the system of the protection of intellectual property rights becoming more and more complete in developing countries and regions, the patent applications of developed countries in them have been significantly improved at the quantity and quality. This provides developing countries and regions with potential favorable conditions for the improvement of technological innovation capacity and the formation of innovative mechanisms, developing countries can take full advantage of the technology spillover effects of foreign patent applications to narrow the technology gap with developed countries. As important path of international technology diffusion, whether foreign patent application has had significant technology spillover effects on the developing countries and how to make use of it to boost technological advance have been paid attention by scholars both at home and abroad.
Using panel data of 27 provinces from 1985 to 2006, this paper studies the impact of foreign patent applications in China on domestic total factor productivity. Empirical results show that: patent applications in China by multinational companies do not have a direct role on China's technological progress, but indirectly promote technological progress by technology diffusion to other domestic firms. Overall, the Positive direct effect of the patent application in China by multinational corporations is offset by the negative direct effect, and foreign patent applications did not boost the total factor productivity of our country on the whole. On the district level, the eastern region got larger indirect spillover effects of capital stock of foreign R&D because of its economic and geographical advantages, but suffered greater direct technical squeeze by foreign companies because of the intellectual property protection. In addition, the combined technological progress effect of the R&D capital stock spilled by foreign patent applications on the eastern, central and western regions are all negative. The results demonstrate that the indirect technology spill effect of the patent applications of multinational corporations in China has positive significance on the improvement of our technological level; however, our domestic R&D investment is still the main “source”of China's technological progress at present.
本文利用中国27个省市1985年到2006年面板数据,研究了外国公司在华专利申请对我国全要素生产率的影响。实证结果表明,跨国公司在华专利申请对我国技术进步并没有产生直接溢出效应,但可以间接激励我国本土企业加强自主研发,从而促进我国技术进步;从总体效应看,跨国公司在华专利申请负的直接效应抵消了正的间接效应,总体上并没有对我国的全要素生产率产生推动作用。从地区层面看,东部地区由于其经济和地域优势一方面获得较大的外国研发资本存量间接溢出效应,但也由于知识产权的保护受到外国企业较大的直接技术挤压;另外,跨国公司在华专利申请溢出的国外研发资本存量对东、中、西等各地区技术进步的综合影响溢出效应都为负。研究结果同时表明,跨国公司在华专利申请的间接技术溢出效应对社会整体科技水平的提高有积极意义,但目前我国研发投入仍然是我国技术进步的主要“源泉”。
With the globalization of economy,a country's technological progress is not only affected by the domestic technological innovation but also by the international factors. This effect is particularly evident in developing countries and regions whose technological innovation capacity is weak. With the system of the protection of intellectual property rights becoming more and more complete in developing countries and regions, the patent applications of developed countries in them have been significantly improved at the quantity and quality. This provides developing countries and regions with potential favorable conditions for the improvement of technological innovation capacity and the formation of innovative mechanisms, developing countries can take full advantage of the technology spillover effects of foreign patent applications to narrow the technology gap with developed countries. As important path of international technology diffusion, whether foreign patent application has had significant technology spillover effects on the developing countries and how to make use of it to boost technological advance have been paid attention by scholars both at home and abroad.
Using panel data of 27 provinces from 1985 to 2006, this paper studies the impact of foreign patent applications in China on domestic total factor productivity. Empirical results show that: patent applications in China by multinational companies do not have a direct role on China's technological progress, but indirectly promote technological progress by technology diffusion to other domestic firms. Overall, the Positive direct effect of the patent application in China by multinational corporations is offset by the negative direct effect, and foreign patent applications did not boost the total factor productivity of our country on the whole. On the district level, the eastern region got larger indirect spillover effects of capital stock of foreign R&D because of its economic and geographical advantages, but suffered greater direct technical squeeze by foreign companies because of the intellectual property protection. In addition, the combined technological progress effect of the R&D capital stock spilled by foreign patent applications on the eastern, central and western regions are all negative. The results demonstrate that the indirect technology spill effect of the patent applications of multinational corporations in China has positive significance on the improvement of our technological level; however, our domestic R&D investment is still the main “source”of China's technological progress at present.
引文
[1] Keller W. Knowledge spillovers at the World’s Technology Frontier[J]. CEPR Working paper, 2001,(11):2816-2817
[2] Macdougall A. The benefits and costs of private investment from abroad: a theoretical approach[J]. Bulletin of the Oxford University Institute of Statistics, 1960, (22): 189-211
[3] Caves R.Multinational firms, competition and productivity in host-country markets[J]. Economics, 1974, (41):176-193
[4] Findlay R.Relative backwardness, Direct Foreign Investment, and the Transfer of Technology:A simple Dynamic Model[J].Quarterly Journal of Economics, 1978, (62):1-16
[5] Young A.Learning-by-doing and the dynamic effects of international trade[J].Quarterly Journal of Economics, 1991,(5):369-405
[6]王红领,李稻葵,冯俊新.FDI与自主研发:基于行业数据的经验研究[J].经济研究, 2006, (2):44-65
[7]亓朋,许和连,艾洪山.外商直接投资企业对内资企业的溢出效应:对中国制造业企业的实证研究[J].管理世界, 2008, (4):58-68
[8]邹武鹰,亓朋,许和连.出口贸易对我国技术创新的影响效应研究[J].湖南大学学报(社会科学版), 2007, (4):57-63
[9] Coe David T,Helpman Elhanan,Hoffmaister,Alexander W.North-South R&D spillovers[J]. The Economic Journal, 1997, (107):134-149
[10] Crespo,Jorge,Martin,Carmela,Velazquez,Francisco J.International technology diffusion through imports and its impact on economic growth[J]. European Economy Group Working Papers, 2002, (97):5032-5033.
[11]赖明勇,许和连,包群.出口贸易与经济增长--理论、模型及实证[M].上海:三联书店出版社
[12]冼国民,薄文广.外国直接投资对中国企业技术创新作用的影响:基于产业层面的分析[J].南开经济研究, 2005, (6):22-35
[13] Eaton J, Kortum S. Trade in ideas: patenting and Productivity in ideas: patenting and productivity in the OECD[J]. Journal of International Economics, 1996, (40): 251-278
[14] Bin Xu,Eric P. Chiang. Trade, patents and intellectual technology diffusion[J].Journal of International Economics, 2000, (14):115-135
[15] Albert G.Z Hu,Adam B Jaffe. Patent Citations and International Knowledge Flow: The Cases of Korea and Taiwan[J], NBER Working Papers, 2001: 8528
[16] Helpman. Innovation, imitation, and intellectual property rights[J]. Econometrical, 1993, (61):1247-1280
[17] Glass Amy Jocelyn,Saggi Kamal. Intellectual property right and foreign direct investment[J]. Journal of International Economics, 2002, (56):387-410
[18] P H Schneider.Intemational trade,economic growth and intellectual property rights:A panel data study of developed and developing countries[J]. Journal of Development Economics, 2005,78(2):529 -547
[19] Cohen, Nelson, JP Walsh.R&D spillovers, patents, and the incentives to innovate in Japan and the United States[J]. Research. Policy, 2002,(31): 1349-1367
[20] Bronwyn H,R H Ziedonis.The patent paradox revisited: an empirical study of patenting in the U S semiconductor industry, 1979-1995[J].Rand Journal of Economics, 2001, (32):101-125
[21] O'Donoghue,Ted,Josef Zweimüller. Patents in a Model of Endogenous Growth[J]. Journal of Economic Growth, 2004, 9(1): 81-123
[22] Peri,Giovanni.Knowledge flows, RD spillovers and innovation[M]. Davis Manuscript :University of California
[23]李平,刘建国. FDI、国外专利申请与中国各地区的技术进步—国际技术扩散视角的实证分析[J].国际贸易问题, 2006, (7):99-104
[24]李平,孙灵燕.国外专利申请对技术进步的影响—基于中国各地区面板数据的分析[J].经济经纬, 2007, (1):40-43
[25]李平,崔喜君.进口贸易与国外专利申请对中国区域技术进步的影晌[J].世界经济研究, 2007, (1):28-32
[26]郭孝刚,刘思峰,方志耕.国外技术扩散对我国制造业研发活动的影响[J].科技进步与对策, 2008, (5):69-71
[27]黄瑞华,祁红梅,彭晓春.基于合作创新的知识产权共享伙伴选择分析[J].科学学与科学技术管理, 2004, (11):24 -28
[28]朱雪忠,詹映,蒋逊明.技术标准下的专利池对我国自主创新的影响研究[J].科研管理, 2007, (2):180-186
[29]杨中楷,孙玉涛.外国在华专利申请影响因素实证分析[J].科技管理研究,2008, (12): 455-457
[30]易先忠,张亚斌.技术差距、知识产权保护与后发国技术进步[J].数量经济技术经济研究, 2006, (10):111-121
[31]韩玉雄,李怀租.知识产权保护对社会福利水平的影响[J].世界经济,2003,(9): 69-80
[32]裴宏,徐进.汤姆逊MP3专利城门起火[N].中国知识产权报, 2005-11-02
[33]谢光亚,王之惠,王宇.跨国公司在华专利战略的变化研究[J].科技管理研究, 2006,(5):61-64
[34]杨海,余峰.论我国企业对国际失效专利的利用[J].科技情报开发与经济,2005, (19):193-194
[35]俞文华.韩国在华发明专利申请格局、技木结构与比较优势及政策含义[J].中国科技论坛,2007,(7):132-140
[36]俞文华.美国在华技术比较优势演变及其政策含义—基于1985—2003年美国在华职务发明专利申请统计分析[J].科学学研究,2008,(1):98-104
[37]张洪吉,毛吴.中外在华职务发明专利申请的比较研究[J].中国科技论坛,2007, (6):129-133
[38]寻舸.论跨国公司的技术扩散效应及对我国的启示[J].科技创业月刊,2004,(3): 41-42
[39] McCallum, John. National borders matter: Canada-U.S. regional trade patterns[J]. American Economic Review, 1995, (85):615-623
[40] Cohen,Wesley M,Richard R,Nelson,John P Walsh.Protecting Their Intellectual Assets: Appropriability Conditions and why U. S. Manufacturing Firms Patent (or not)[J].National Bureau of Economic Research Working Paper, 2000,(105):7552-7553
[41] Almeida.P.Knowledge sourcing by foreign MNEs:patent citation analysis in the US semiconductor industry[J]. Strategic Management Journal ,1996, (17):155-165
[42]龚荒,王元地.中国专利制度与经济增长关系的实证研究[J].科技管理研究,2008, (1):179-181
[43] Encaoua David,Guellec,Dominique,Martinez,Catalina.Patent systems for encouraging innovation: Lessons from economic analysis[J]. Research Policy, 2006, (9): 1423-1440
[44] Nelson, Richard, Edmund Phelps. Investment in Humans, Technological Diffusion, and Economic Growth[J].American Economic Review, 1999, (61):724-756
[45] Borensztein E, Gregorio J, lee J W. How does foreign investment affect economic growth[J]. Journal of international economics,1988,(45):115-135
[46]李杏.外商直接投资技术外溢吸收能力影响因素研究[J].国际贸易问题,2007,(12): 79-86
[47] Griffith,Gedding,Van Reenen,Hsiu Ling Wu, Chien-Hsun Chen. An Assessment ofOutward Foreign Direct Investment from China’s Transitional Economy[J]. Europe-Asia Studies, 2001, 53(8):1235-1254
[48] Fagerberg J.Technology and international differences in growth rates[J].Journal of Economic literature, 1994, (32):1147-1175
[49] Kokko A.Technology, Market Characteristic and Spillovers[J].Journal of Development Economics,1994,(43):279-293
[50]宋河发.全球最大500家跨国公司在华专利战略的特点、问题与对策[J].中国科技论坛,2005,(11):70-74
[51] Levin A,L K Raut.Complementarities between export and human capital in economic growth: evidence from the semi-industrialized countries[J]. Economic Development and Cultural Change, 1997,(10):155-174
[52]张军,吴桂英,张吉鹏.中国省际物质资本存量估算:1952 ~2000[J].经济研究, 2004,(10):25-44
[53]叶裕民.全国及各省区市全要素生产率的计算和分析.经济学家,2002,(3): 115-121
[54] Griliches.R&D and the Productivity Slowdown[J].American Economic Review, 1980,70(2):343-348
[55] David T.Coe and Elhanan Helpman.International RD Spillovers[J]. European economics review,1995,(39):859-887
[56]王晖.国外直接投资对我国技术创新的影响—基于专利角度分析[J].经济问题, 2006,(11):25-26
[57] Barney.Firm resource and sustained competitive advantage[J].Journal of Management,1991,(1):99-120
[58]李琳.警惕跨国公司滥用知识产权[J].科学决策,2005,(12):56-58
[59]毛昊.关于2002年一份德国企业专利统计调查问卷结果的思考[J].专利统计简报, 2008, (20):1-12
[60]崔喜君.国外专利申请的技术溢出效应研究[D].山东理工大学,2007,(3)
[61]任声策,宣国良.国外企业的专利行为分析[J].情报科学,2006,(9):1286-1291
[62]王新华.跨国公司专利战略分析及应对策略构建[J].对外经贸实务,2004,(7): 29-32
[63] Kortum S,J Lerner.Stronger protection or technological revolution: what is behind the recent surge in patenting? [J]. Carnegie-Rochester Conference Series on Public Policy,1998,(48): 247-304
[64] Phschnider.1ntemational trade, economic growth and intellectual property rights: A panel data study of developed and developing countries[J].Journal ofDevelopment Economics,2005,78(2):529-547
[65] Todonghue, J zweimuller. Patents in a model of endogenous growth[J].Journal of Economic Growth,2004,(1):81-123
[66] Lichtenberg F,Pottelsberghe,Potterie. International R&D spillovers:A Reexamination[J].NBER Working Paper, 1996,(3):5688-5689
[2] Macdougall A. The benefits and costs of private investment from abroad: a theoretical approach[J]. Bulletin of the Oxford University Institute of Statistics, 1960, (22): 189-211
[3] Caves R.Multinational firms, competition and productivity in host-country markets[J]. Economics, 1974, (41):176-193
[4] Findlay R.Relative backwardness, Direct Foreign Investment, and the Transfer of Technology:A simple Dynamic Model[J].Quarterly Journal of Economics, 1978, (62):1-16
[5] Young A.Learning-by-doing and the dynamic effects of international trade[J].Quarterly Journal of Economics, 1991,(5):369-405
[6]王红领,李稻葵,冯俊新.FDI与自主研发:基于行业数据的经验研究[J].经济研究, 2006, (2):44-65
[7]亓朋,许和连,艾洪山.外商直接投资企业对内资企业的溢出效应:对中国制造业企业的实证研究[J].管理世界, 2008, (4):58-68
[8]邹武鹰,亓朋,许和连.出口贸易对我国技术创新的影响效应研究[J].湖南大学学报(社会科学版), 2007, (4):57-63
[9] Coe David T,Helpman Elhanan,Hoffmaister,Alexander W.North-South R&D spillovers[J]. The Economic Journal, 1997, (107):134-149
[10] Crespo,Jorge,Martin,Carmela,Velazquez,Francisco J.International technology diffusion through imports and its impact on economic growth[J]. European Economy Group Working Papers, 2002, (97):5032-5033.
[11]赖明勇,许和连,包群.出口贸易与经济增长--理论、模型及实证[M].上海:三联书店出版社
[12]冼国民,薄文广.外国直接投资对中国企业技术创新作用的影响:基于产业层面的分析[J].南开经济研究, 2005, (6):22-35
[13] Eaton J, Kortum S. Trade in ideas: patenting and Productivity in ideas: patenting and productivity in the OECD[J]. Journal of International Economics, 1996, (40): 251-278
[14] Bin Xu,Eric P. Chiang. Trade, patents and intellectual technology diffusion[J].Journal of International Economics, 2000, (14):115-135
[15] Albert G.Z Hu,Adam B Jaffe. Patent Citations and International Knowledge Flow: The Cases of Korea and Taiwan[J], NBER Working Papers, 2001: 8528
[16] Helpman. Innovation, imitation, and intellectual property rights[J]. Econometrical, 1993, (61):1247-1280
[17] Glass Amy Jocelyn,Saggi Kamal. Intellectual property right and foreign direct investment[J]. Journal of International Economics, 2002, (56):387-410
[18] P H Schneider.Intemational trade,economic growth and intellectual property rights:A panel data study of developed and developing countries[J]. Journal of Development Economics, 2005,78(2):529 -547
[19] Cohen, Nelson, JP Walsh.R&D spillovers, patents, and the incentives to innovate in Japan and the United States[J]. Research. Policy, 2002,(31): 1349-1367
[20] Bronwyn H,R H Ziedonis.The patent paradox revisited: an empirical study of patenting in the U S semiconductor industry, 1979-1995[J].Rand Journal of Economics, 2001, (32):101-125
[21] O'Donoghue,Ted,Josef Zweimüller. Patents in a Model of Endogenous Growth[J]. Journal of Economic Growth, 2004, 9(1): 81-123
[22] Peri,Giovanni.Knowledge flows, RD spillovers and innovation[M]. Davis Manuscript :University of California
[23]李平,刘建国. FDI、国外专利申请与中国各地区的技术进步—国际技术扩散视角的实证分析[J].国际贸易问题, 2006, (7):99-104
[24]李平,孙灵燕.国外专利申请对技术进步的影响—基于中国各地区面板数据的分析[J].经济经纬, 2007, (1):40-43
[25]李平,崔喜君.进口贸易与国外专利申请对中国区域技术进步的影晌[J].世界经济研究, 2007, (1):28-32
[26]郭孝刚,刘思峰,方志耕.国外技术扩散对我国制造业研发活动的影响[J].科技进步与对策, 2008, (5):69-71
[27]黄瑞华,祁红梅,彭晓春.基于合作创新的知识产权共享伙伴选择分析[J].科学学与科学技术管理, 2004, (11):24 -28
[28]朱雪忠,詹映,蒋逊明.技术标准下的专利池对我国自主创新的影响研究[J].科研管理, 2007, (2):180-186
[29]杨中楷,孙玉涛.外国在华专利申请影响因素实证分析[J].科技管理研究,2008, (12): 455-457
[30]易先忠,张亚斌.技术差距、知识产权保护与后发国技术进步[J].数量经济技术经济研究, 2006, (10):111-121
[31]韩玉雄,李怀租.知识产权保护对社会福利水平的影响[J].世界经济,2003,(9): 69-80
[32]裴宏,徐进.汤姆逊MP3专利城门起火[N].中国知识产权报, 2005-11-02
[33]谢光亚,王之惠,王宇.跨国公司在华专利战略的变化研究[J].科技管理研究, 2006,(5):61-64
[34]杨海,余峰.论我国企业对国际失效专利的利用[J].科技情报开发与经济,2005, (19):193-194
[35]俞文华.韩国在华发明专利申请格局、技木结构与比较优势及政策含义[J].中国科技论坛,2007,(7):132-140
[36]俞文华.美国在华技术比较优势演变及其政策含义—基于1985—2003年美国在华职务发明专利申请统计分析[J].科学学研究,2008,(1):98-104
[37]张洪吉,毛吴.中外在华职务发明专利申请的比较研究[J].中国科技论坛,2007, (6):129-133
[38]寻舸.论跨国公司的技术扩散效应及对我国的启示[J].科技创业月刊,2004,(3): 41-42
[39] McCallum, John. National borders matter: Canada-U.S. regional trade patterns[J]. American Economic Review, 1995, (85):615-623
[40] Cohen,Wesley M,Richard R,Nelson,John P Walsh.Protecting Their Intellectual Assets: Appropriability Conditions and why U. S. Manufacturing Firms Patent (or not)[J].National Bureau of Economic Research Working Paper, 2000,(105):7552-7553
[41] Almeida.P.Knowledge sourcing by foreign MNEs:patent citation analysis in the US semiconductor industry[J]. Strategic Management Journal ,1996, (17):155-165
[42]龚荒,王元地.中国专利制度与经济增长关系的实证研究[J].科技管理研究,2008, (1):179-181
[43] Encaoua David,Guellec,Dominique,Martinez,Catalina.Patent systems for encouraging innovation: Lessons from economic analysis[J]. Research Policy, 2006, (9): 1423-1440
[44] Nelson, Richard, Edmund Phelps. Investment in Humans, Technological Diffusion, and Economic Growth[J].American Economic Review, 1999, (61):724-756
[45] Borensztein E, Gregorio J, lee J W. How does foreign investment affect economic growth[J]. Journal of international economics,1988,(45):115-135
[46]李杏.外商直接投资技术外溢吸收能力影响因素研究[J].国际贸易问题,2007,(12): 79-86
[47] Griffith,Gedding,Van Reenen,Hsiu Ling Wu, Chien-Hsun Chen. An Assessment ofOutward Foreign Direct Investment from China’s Transitional Economy[J]. Europe-Asia Studies, 2001, 53(8):1235-1254
[48] Fagerberg J.Technology and international differences in growth rates[J].Journal of Economic literature, 1994, (32):1147-1175
[49] Kokko A.Technology, Market Characteristic and Spillovers[J].Journal of Development Economics,1994,(43):279-293
[50]宋河发.全球最大500家跨国公司在华专利战略的特点、问题与对策[J].中国科技论坛,2005,(11):70-74
[51] Levin A,L K Raut.Complementarities between export and human capital in economic growth: evidence from the semi-industrialized countries[J]. Economic Development and Cultural Change, 1997,(10):155-174
[52]张军,吴桂英,张吉鹏.中国省际物质资本存量估算:1952 ~2000[J].经济研究, 2004,(10):25-44
[53]叶裕民.全国及各省区市全要素生产率的计算和分析.经济学家,2002,(3): 115-121
[54] Griliches.R&D and the Productivity Slowdown[J].American Economic Review, 1980,70(2):343-348
[55] David T.Coe and Elhanan Helpman.International RD Spillovers[J]. European economics review,1995,(39):859-887
[56]王晖.国外直接投资对我国技术创新的影响—基于专利角度分析[J].经济问题, 2006,(11):25-26
[57] Barney.Firm resource and sustained competitive advantage[J].Journal of Management,1991,(1):99-120
[58]李琳.警惕跨国公司滥用知识产权[J].科学决策,2005,(12):56-58
[59]毛昊.关于2002年一份德国企业专利统计调查问卷结果的思考[J].专利统计简报, 2008, (20):1-12
[60]崔喜君.国外专利申请的技术溢出效应研究[D].山东理工大学,2007,(3)
[61]任声策,宣国良.国外企业的专利行为分析[J].情报科学,2006,(9):1286-1291
[62]王新华.跨国公司专利战略分析及应对策略构建[J].对外经贸实务,2004,(7): 29-32
[63] Kortum S,J Lerner.Stronger protection or technological revolution: what is behind the recent surge in patenting? [J]. Carnegie-Rochester Conference Series on Public Policy,1998,(48): 247-304
[64] Phschnider.1ntemational trade, economic growth and intellectual property rights: A panel data study of developed and developing countries[J].Journal ofDevelopment Economics,2005,78(2):529-547
[65] Todonghue, J zweimuller. Patents in a model of endogenous growth[J].Journal of Economic Growth,2004,(1):81-123
[66] Lichtenberg F,Pottelsberghe,Potterie. International R&D spillovers:A Reexamination[J].NBER Working Paper, 1996,(3):5688-5689
© 2004-2018 中国地质图书馆版权所有 京ICP备05064691号 京公网安备11010802017129号 地址：北京市海淀区学院路29号 邮编：100083 电话：办公室：(+86 10)66554848；文献借阅、咨询服务、科技查新：66554700 |