中文摘要：

利用海淀区R＆D资源清查中671家企业数据，考察全部样本以及产业和企业所有制结构差异下不同类型R＆D支出对企业生产率的影响，结果表明：（1）R＆D投入对企业生产率有显著正向影响，知识密集型服务业企业的R＆D产出弹性与制造业企业相差不大，不同类型企业的弹性系数依民营、国有和外资企业递减。（2）在全部样本中，R＆D经费内、外部支出都对企业生产率有正向影响，且前者影响更大，同时二者还存在互补效应。产业差异下的研究结果与全部样本一致，但是R＆D经费外部支出对知识密集型服务业企业生产率的影响更大，互补效应也更加突出。R＆D经费内部支出对国有企业和民营企业的生产率都有正向影响，但是R＆D经费外部支出仅对民营企业生产率有促进作用。

英文摘要：

Using enterprise data of 671 firms in Haidian district from R＆D resource census, this paper examines the effect of various types of R＆D on firm＇s productivity respectively based on the analysis of full sample, samples of different industries and various ownership firms, and the main conclusions are as followed：（1） R＆D has positive effect on firm＇s productivity, and the R＆D capital output elasticity of knowledge intensive business service firms is as large as the corresponding elasticity of manufacturing firms. Whereas, the R＆D capital output elasticity descends by private enterprises, state-owned enterprises, foreign-invested enterprises. （2） Based on the analysis of full sample, we find both internal and external R＆D have positive impact on firm＇s productivity, but the effect of internal R＆D is larger. Moreover, there exists complementary effect between internal and external R＆D. The empirical results about the samples of different industries are in line with that of full sample, but the impact elasticity of external R＆D on productivity of knowledge intensive business service firms is larger than that of manufacturing firms. Moreover, the complementary effect is also larger in knowledge intensive business service. Internal R＆D has positive impact on the productivity of both state-owned and private enterprises. However, external R＆D just takes significant effect on private enterprises＇ productivity.