中国农业公共R&D投入知识存量及收益率再测算

Re-evaluation of the knowledge stock and rates of return to China’s agricultural public research and development

为了精确计算中国农业R&D投入收益率,为农业科研投入政策的制定提供可参考的科学依据,本文基于1966—2018年中国农业公共R&D投入数据,使用网格搜索法建立了适合计算中国农业知识存量的Gamma分布参数,计算了农业知识存量,并运用Cochrane-Orcutt模型估计了中国农业知识存量对农业全要素生产率(TFP)的弹性,最后使用MIRR方法计算了中国农业公共R&D投入的修正内部收益率。研究结果表明,中国农业公共R&D投入的平均修正内部收益率为36.49%,且随时间推移持续增长。同时,通过与国内外相关研究比较,发现虽然先前研究略微高估了中国农业公共R&D投入的内部收益率,但中国仍在世界范围内处于较高水平。

Using the input data of China’s agricultural public R&D(Research&Development)from 1966 to 2018,this paper utilizes a grid search method to establish a lagging distribution suitable for studying the stock of public R&D knowledge in China’s agriculture and utilizes different models to estimate the knowledge stock.Identifying of the elasticity of agricultural total factor productivity,the modified internal rates of return of China’s agricultural public R&D input is calculated.The results found that the average modified internal rates of return to China’s agricultural public R&D investment were 36.49%,and it continued to increase over time.By comparing with relevant domestic and foreign research,it is found that the previous research slightly overestimated the internal rates of return to China’s agricultural public R&D investment.However,it is still at a relatively high level worldwide.