近年来，我国居民收入差距呈现下降趋势，但仍然较大。同时，数字经济方兴未艾，是农业经济、工业经济之后的主要经济形态，对促进经济增长、提升居民收入具有重要作用。因此，研究数字经济与收入不平等的关系具有重要学术价值和实践意义。首先，本文建立了理论模型，研究数字经济发展对收入不平等的影响及其机制。结合现实数据，本文将产业划分为工业和非工业（主要是服务业），将公司岗位划分为资本岗位、低技能劳动岗位和高技能劳动岗位，劳动者能够在相同技能岗位间流动。研究发现，数字经济引发的“机器换人”和“岗位创造”规模不同导致公司对各类劳动者需求不同，进而导致收入不平等变化的方向和大小不同。如果数字经济使得非工业部门低技能劳动岗位增加更多，那么相比于高技能劳动者，低技能劳动者需求增加，收入增速更大，因此双方收入差距将会缩小。接下来，本文使用工具变量法在宏观层面对数字经济和收入不平等的关系进行了因果识别。研究发现，数字经济发展可以显著降低收入不平等。此外，本文发现相比于缩小高收入者之间的收入差距，数字经济发展对缩小中低收入者之间收入差距的作用更大。在微观层面，本文也发现数字经济的发展使得低收入者收入增速显著高于高收入者，这便是数字经济发展降低收入不平等的主要原因。最后，为进一步探究数字经济的影响机制，本文重点围绕居民收入构成，从宏观和微观两个维度进行检验。从工资性收入看，数字经济有效降低了工资性收入不平等。原因在于，数字经济发展一方面引发工业企业相对更多的“机器换人”，另一方面激发服务业企业创造相对更多的岗位，服务业因而可以吸纳工业企业富余的劳动力。在潜在供需力量作用下，低技能劳动者工资增幅大于高技能劳动者，二者收入差距逐渐缩小，这与理论模型结论一致。此外，从经营性收入和转移性收入看，本文未发现数字经济对其产生影响，这也在一定程度上排除了其他潜在机制。综上所述，本文研究结果表明，我国数字经济的发展可以显著降低收入不平等，主要原因在于数字经济通过“机器换人”和“岗位创造”的综合作用，降低了工资性收入不平等。本研究补充了相关领域的学术文献，对探索如何降低居民收入不平等具有重要的实践意义。
In recent years, the income gap of Chinese residents has shown a downward trend, but it is still large. At the same time, digital economy is in the ascendant, which is the main economic form after agricultural economy and industrial economy. It plays an important role in promoting economic growth and improving residents‘ income. Therefore, studying the relationship between digital economy and income inequality has important academic value and practical significance.Firstly, this paper establishes a theoretical model to study the impact of digital economy on income inequality and its mechanism. Based on practical data, this paper divides companies into industrial and non-industrial companies, and divides company positions into capital positions, low-skilled labor positions, and high-skilled labor positions. Workers can flow between the same skilled positions. The study finds that the different scales of machine replacement and job creation triggered by digital economy lead to different demands on two types of workers by companies, which in turn leads to different directions and sizes of changes in income inequality. If digital economy increases the number of low-skilled labor positions in the non-industrial sector by more, then compared to high-skilled workers, the demand for low-skilled workers will increase and the income growth rate will be greater, so the income gap between the two sides will narrow.Next, this paper uses the instrumental variable method to identify the causal relationship between digital economy and income inequality at the macro level. Research has found that the development of digital economy can significantly reduce income inequality. In addition, this paper finds that the development of digital economy plays a greater role in narrowing the income gap between low-income people than in narrowing the income gap between high-income people. At the micro level, this paper also finds that the development of digital economy has made the income growth of low-income people significantly higher than that of high-income people, which is the main reason why digital economy reduces income inequality.Finally, in order to further explore the impact mechanism of digital economy, this paper focuses on the composition of residents‘ income, examining it from macro and micro levels. From the perspective of wage income, digital economy has effectively reduced wage income inequality. The reason is that the development of digital economy has on the one hand triggered more machine replacement of industrial enterprises, and on the other hand created more service industry jobs, which can absorb the surplus labor force of industrial enterprises. Under the influence of potential supply and demand forces, the wage growth of low-skilled workers is greater than that of high-skilled workers, and the income gap between the two gradually narrows, which is consistent with the theoretical model’s conclusions. From the perspective of operational income and transfer income, this paper does not find that digital economy has an impact on them, which to some extent excludes other impact mechanisms.In summary, the results of this study indicate that the development of China‘s digital economy can significantly reduce income inequality, mainly because digital economy has reduced wage income inequality through machine replacement and job creation. This paper supplements academic literature in relevant fields, which has important practical significance for exploring how to reduce income inequality.
