收入水平、收入差距与自主创新--兼论“中等收入陷阱”的形成与跨越

Income Level,Income Gap and Independent Innovation:The Formation and Escaping of the Middle-income Trap

本文构建了一个连续收入分布和创新不确定环境下企业产品创新的数理模型,突破了以往研究中收入两分法、不区分企业类型及消费者匹配的局限性。通过模型推导和数值模拟发现:在经济发展的不同阶段,消费者收入水平与收入差距的不同组合对内资企业的自主创新行为会产生迥然不同的影响:当经济体处于中低收入阶段时,收入差距的扩大并不会抑制自主创新与经济增长;但当进入中高收入阶段后,如果收入差距未能随着收入水平的提高而不断缩小,不仅自主创新将会受到抑制,经济增长也将陷入停滞。这一微观机制解释了许多贫富分化严重的后发国家在进入中等收入水平的发展阶段后,无法顺利转型为创新驱动的增长模式,落入"中等收入陷阱"的原因。本文还运用中国内资企业分行业面板数据进一步验证了模型的推论。本文有助于厘清收入水平与收入差距的不同组合对内资企业自主创新的不同影响机理,为中国实施创新驱动发展战略,跨越"中等收入陷阱"提供了参考。

Most research on the middleincome trap adopts the political economy perspective with an emphasis on how large income gaps lead to dissatisfaction in the poor,a confrontation between the rich and poor and social unrest in Latin American and Asian countries when entering the middleincome stage(Cai&Wang,2014).Others have a onesided emphasis on middleincome countriesweak economic growth due to the loss of cost advantages and a lack of technological innovation(Yao&Han,2015).In addition to extreme examples that seriously affect social stability,more mundane factors such as demand pull,income level and income gap intermediate the effect technological innovation has on the formation of a middleincome trap.This complex mechanism is the key point to explore for the innovationdriven development strategy currently used in China to get out of the middleincome trap.Using a vertical product differentiation model,this paper introduces a continuous symmetric trapezoid density function to describe the income distribution of consumers and to construct a mathematical model of the impact of income levels and income gaps on product innovation under innovation uncertainty.Combining this with a new product diffusion model,this paper develops a mathematical model of the impact of income level and income gap on economic growth from a macroeconomic perspective.Through model simulations,we depict the influence of income levels and income gaps on microeconomic independent innovation and macroeconomic growth under different growth patterns,revealing the formation mechanism and the escaping path of the middleincome trap.This paper uses panel data on 29 Chinese manufacturing industries from 1998 to 2008 from the China Statistical Yearbook on Science and Technology to verify the model.This paper concludes that different combinations of income levels and income gaps have totally different impacts on the independent innovation behavior of domestic enterprises in the different stages of economic development.In the lowincome stage,the expansion of the income gap will not inhibit independent innovation and economic growth.In the middleand upperincome stages,if the income gap does not shrink when income levels increase,independent innovation will be inhibited and economic growth will stagnate.This microeconomic mechanism explains why many polarizing developing countries fail to progress to an innovationdriven growth mode and fall into the middleincome trap when they enter the middleincome stage.More importantly,if income gaps cannot be effectively reduced as income levels increase,developing countries cannot avoid economic stagnation even though R&D efficiency and the upper limit of product quality might increase.If income gaps can be narrowed when income levels increase,developing countries can get out of the middleincome trap successfully.These results suggest that economic growth in developing countries does not necessarily bring about improvements in the independent innovation of domestic enterprises.To improve the ability of domestic enterprises to independently innovate,the Chinese government must focus on a policy of narrowing the income gap and adopt the following policy of demand pull and technology push.First,from the view of demand pull,the government should promote the reform of the income distribution system.Second,because the high Gini coefficient of China is mainly due to the large income gap between urban and rural areas,the government could narrow the income gap by raising the level of urbanization to achieve inclusive growth.Finally,in terms of technology push,compared with increasing the quantity of R&D input,the government should pay more attention to the institutional improvement of innovation to enhance R&D efficiency.The most important innovation of this paper is the construction of a product innovation model of domestic enterprises with a continuous income distribution under innovation uncertainty,breaking the limitation of an income dichotomy and ignoring different types of enterprises and consumers matching.This clarifies that different combinations of income levels and gaps have different influences on innovation by domestic enterprises and economic growth,providing a reference for China to implement an innovationdriven development strategy and cross the middleincome trap.