农业科技创新投入要素贡献的动态分析——基于状态空间模型的实证

Dynamic Analysis on Output Contribution of Input Elements in Agricultural Innovation ——Empirical Test Based on State Space Model

笔者在知识生产函数理论基础上,依据我国1990年～2009年农业科技创新时序数据,检验变量平稳性及协整关系,并以此为基础构建变系数状态空间模型,刻画农业科技创新投入要素贡献的动态效应。结果表明,1990年～2009年研发支出和研发人员的产出弹性呈现出完全相反的趋势:研发支出贡献为正值,并自1994年以后一直稳步上升;而研发人员贡献为负值,从1992年开始一直下降,直到1999年才开始逐步收敛于一定值且持续至今。研发支出和研发人员要素稀缺性、质量差异以及农业科技发展的特殊性导致农业科技创新投入要素的产出贡献呈现不同的趋势与阶段特征。

Based on the theory of the knowledge production function, by using the time series data of agricultural innovation from 1990 to 2009, the paper tests the smoothness of variables and the cointegration relationship by building state-space model with variable coefficients to describe contributions to agricuhural innovation in the dynamic inputs effect. The results show： from 1990 to 2009 output elasticity of R＆D expenditures and R＆D staff keep opposite trends. R＆D expenditures contribute to positive which since 1994 has been steadily rising, while the negative contribution of R＆D staff from 1992 onwards has been declining until 1999 and gradually converged to a certain value and continues today. Elements scarcity of R＆D expenditures and R＆D staff, quality differences and specificity of development of agricultural science and technology led to different trends and characteristics of output contribution of input elements in agricuhural innovation.