研发投入对企业绩效影响的门槛效应

基于中国智慧城市上市企业的相关数据，运用面板门槛回归方法实证研究研发投入对企业绩效影响的异质门槛效应。结果表明:（1）研发投入对企业绩效的影响呈现显著的“倒U形”非线性特征，即只有适度的研发投入强度才能促进企业绩效，而过高的研发投入强度会对企业绩效产生一定的抑制作用；（2）在企业规模约束下，研发投入对企业绩效具有“U形”非线性影响，说明只有当企业规模跨越一定门槛时，研发投入才能促进企业绩效；（3）在资本结构和资本密度门槛条件下，研发投入对企业绩效的影响分别具有显著的“倒N形”型和“N形”非线性特征，且均存在最优水平区间；（4）新常态下，有效促进研发投入对企业绩效积极影响的重要抓手在于，兼顾研发投入能力和管理能力并重、鼓励企业做大做强、保持适中的资本结构和较高的资本密度水平。

R&D Investment's Threshold Effect on Firm Performance

Based on the related data of listed companies in China's smart cities from 2011 to 2015, by means of panel threshold regression technique, this paper makes an empirical study of R&D investment's heterogeneous threshold effect on firm performance. The results show that:(1)R&D investment has an obvious nonlinear inverted U-type influence on firm performance, and only modest R&D input could promote firm performance, while if the investment is excessive, it could generate an inhibitory effect;(2) Constrained by enterprise scale, R&D input's effect on firm performance is featured by nonlinear U-style. Thus, it can be seen that only when the enterprise scale goes above a certain threshold, R&D investment can advance firm achievement;(3)Under the threshold of capital structure and the threshold of capital density, R&D input has a significant inverted N-type and nonlinear N-style effect on firm performance. At the same time, the optimal capital structure and capital intensity level range could be identified;(4) Under the ‘New Norm’, to further activate R&D input's positive effect on firm performance, we must grasp these key points-to pay equal attention to both R&D and management capability, to further strengthen and expand enterprise development, and to keep the modest capital structure and higher capital density level.