Abstract: Studying the impact of tax reduction on corporate innovation is of great significance for Chinas highquality economic development. Drawing on the 20082014 National Innovation Survey Enterprise Database of the National Bureau of Statistics, this paper uses dynamic panel threshold model and effective instrumental variables to study whether there is threshold effect of tax reduction of hightech enterprises on corporate innovation. The results of the study indicate that: firstly, there is a “size threshold” for hightech enterprises' tax reduction. Once the tax reduction scale exceeds the “size threshold”, the promotion effect of tax reduction on corporate innovation will be significantly weakened. Secondly, under the same conditions, compared with hightech enterprises with low R&D intensity, the tax reduction of hightech enterprises with high R&D intensity has stronger promoting effect on corporate innovation. Thirdly, under the same conditions, compared with the hightech enterprises in the underdeveloped regions, the tax reduction of hightech enterprises in economically developed regions has a greater promoting effect on corporate innovation. The government should set an upper bound for the scale of tax reduction, and the preferential tax rate of income tax should be linked with the R&D intensity of hightech enterprises.

Key words: tax reduction, corporate innovation, hightech enterprises, dynamic panel threshold model

摘要： 研究政府减税如何影响企业创新，对中国经济高质量发展意义重大。本文使用2008—2014年国家统计局全国创新调查企业数据库数据，运用动态面板门限模型并结合有效工具变量，研究高新技术企业减税对企业创新是否存在门限影响。研究发现：第一，高新技术企业减税对企业创新存在一个大小约为6500的“规模阈值”，15%的所得税优惠政策会促使高新技术企业的减税规模超过“规模阈值”，导致企业创新水平内卷化；第二，在同等条件下，相对于低研发强度的高新技术企业，高新技术企业减税对高研发强度企业创新的促进效应更强，尤其对员工物质激励水平和技术改造能力较高的高新技术企业，其减税规模对企业创新的促进效应更加突出；第三，在同等条件下，相对于欠发达地区的高新技术企业，高新技术企业减税对经济发达地区企业创新的促进效应更大。政府应对高新技术企业的减税规模设置一个上限，且所得税优惠税率应结合企业研发强度和地区经济发展水平进行浮动管理。

关键词: 减税, 企业创新, 高新技术企业, 动态面板门限模型