适度垄断下建筑业技术创新效用模型

中国建筑业技术创新缺乏生机，通过适度垄断来激励建筑企业进行技术创新不失为一种较优选择。文中先假设建筑行业内，超级大企业可以全面地参与行业竞争，运用企业产出模型证明了建筑业适度垄断企业数目确定性问题。其次，以国有大型施工企业为主体，进一步假设在适度垄断下建筑企业连续增加R＆D费用可以提高生产力，并且在建筑企业的生产阶段均有研发（R＆D）投资，运用LaGrange函数建立了适度规模下建筑业技术创新效用模型，模型解揭示我国建筑业企业技术创新效用不明显，同期的建筑业技术创新障碍性因素调查研究和1991-2004建筑业的增长率曲线支持此结论。

Utility Model of Technical Innovation in Construction Industry under Moderate Monopoly

Due to lacking driving force to promote the technology innovation in China construction industry,it may be a better choice to encourage the willing of construction enterprise to undergo the technology innovation by moderate monopoly.So,firstly it is supposed that the super construction enterprise can participate in the industry competition comprehensively,then,this paper proves the possibility to determine the number of monopoly construction enterprises in terms of moderate monopoly by the output mode of enterprise.Secondly,taking the state-owned building enterprise as the main body,it is further supposed that the construction enterprise could improve the productivity by raising the R&D in terms of moderate monopoly and the R&D should be invested in each period of manufacturing,then,this paper has established the utility mode of construction technology innovation by the Lagrange function in terms of moderate monopoly.At last,the finding shows that the technology innovation utility of China construction enterprise is not significant and this conclusion is supported by the growth trend of China construction industry in 1991-2004 and the investigation of the resistance factor to China construction technology innovation.