宏观税负、研发补贴与创新驱动的长期经济增长

Aggregate Tax Burden,R&D Subsidies and Innovation-driven Long-term Economic Growth

随着中国经济步入"新常态"以及中美贸易争端愈演愈烈,科技创新的重要性愈发赢得公众和政策制定者的深刻认同。本文构建了一个基于创新驱动的熊彼特增长框架,将生产性政府支出和宏观税负水平引入质量阶梯模型。理论模型表明:宏观税负水平对长期经济增长存在倒U型作用,即如果宏观税负水平大于(小于)某个阈值时,宏观税负水平的提升会显著降低(提高)稳态经济增长率;同时,研发补贴率对稳态经济增长也存在倒U型作用。并且,最优研发财政补贴政策与税收政策相互依赖,要求政府综合把握政策组合的力度。给定现阶段研发补贴率与研发强度,中国最优宏观税负水平不超过16.9%,总体税率下降1个百分点将使长期人均GDP实际增速提高0.17个百分点;若政府统一协调宏观税负水平和研发补贴率,该政策组合的数值模拟结果表明,最优的宏观税负水平和研发补贴率分别在12.4%-17.8%和41.5%-47.9%之间。因此,2018年以来的"减税降费"政策正合时宜。由理论模型的校准结果观之,目前我国的研发能力仍偏弱,随着国家基础科研实力和科研投入的提升,全社会的研发能力将得到有效提高,从而减税降费对长期经济增长的贡献也将越发显著,本文给出的结果可视为"减税降费"政策对长期经济增长贡献的下限。

Since China stepped into the era of new normal and the trade disputes between China and the United States have intensified,the importance of technological innovations has been deeply recognized by the public and policymakers.Fiscal policy providing tax incentives and subsidies for R&D-intensive firms is able to facilitate the progress of innovations and the long-run economic growth.However,the government needs to finance its expenditures on productive public goods,for example,infrastructures,via taxes.Therefore,a natural tradeoff appears between R&D facilitation and productive government spending based on the tax burden adjustment.Given that the current aggregate tax burden in China is around 18%,the State Council of China has determined to promote the tax and fees reduction policy since the beginning of 2018.Relying on explicit solutions to the theoretical models,this paper demonstrated the interactions among productive government spending,innovations and tax burden.Moreover,based on the model calibration and empirical analysis,we try to find out the optimal tax burden and R&D subsidy policy that maximizes the steady-state economic growth rate in China.Thus,this paper contributes to understanding the growth effects of and provides ground for the recent tax and fees reduction policy.Specifically,this paper developed an innovation-based growth framework by introducing productive government spending and aggregate tax burden into the quality-ladder model.In this model,R&D firms create a(more advanced)new patent to improve the quality of their products(machines).Machines are intermediates in the production of final goods,and only the newest patent holder could produce them and thus enjoys the monopolistic profit.This is the fundamental incentive for R&D investment and technological innovations,which is also the source of the long-run economic growth.However,since the government spending in the model is productive,R&D-promoting tax incentives and subsidies will reduce the room of productive public goods and hinder economic growth.According to the theoretical model,the aggregate tax burden generates an inverted-U shaped effect on the long-term growth.That is,if the aggregate tax burden is higher(lower)than a threshold,an increase in the aggregate tax burden will reduce(boost)the steady-state economic growth rate.Meanwhile,the R&D subsidy rate has an inverted-U shaped effect on the long-term growth as well.Additionally,the optimal R&D subsidy policy and tax policy depend on each other,which requests the government to balance the policy mix carefully.Based on the Chinese macroeconomic data during the recent decade,we carefully calibrated the benchmark model.Given the current R&D subsidy rate and R&D intensity,the optimal aggregate tax burden in China is no more than 16.9%,and a one percentage point reduction in the aggregate tax rate will raise the long-term growth rate of real GDP per capita by 0.17 percentage points.If the government is allowed to coordinate the aggregate tax burden and the R&D subsidy rate,according to the numerical simulation with respect to the policy mix,the optimal aggregate tax burden and R&D subsidy rate are 12.4%-17.8%and 41.5%-47.9%,respectively.In China,the current aggregate tax rate is around 18%and the R&D subsidy rate is at the upper limit of 37.5%,so it is appropriate for the State Council to conduct the tax and fees reduction policy.In particular,the calibrated model parameters show that the R&D efficiency in China is far below that of the United States.This echoes some empirical literature on the performance of R&D in China and reveals tremendous potential for the Chinese government to improve higher education and encourage R&D inputs.The calibrated parameters in the benchmark theoretical model show that the R&D efficiency in China is still underdeveloped.Along with the enhancement in the basic research and R&D intensity,the R&D efficiency will be significantly improved.Also,the tax and fees reduction policy will increasingly contribute to the long-term economic growth.Thus,the benchmark quantitative results obtained from this paper should be taken as the lower bound for the impact of the tax and fees reduction policy on the long-term economic growth.