自中国改革开放以来，中国的出口贸易取得了令世人瞩目的成绩。中国货物出口贸易总额从 1979 年的 136.6 亿美元增长到 2019年的 24994.82 亿美元，四十年间提升了 180 多倍，堪称世界奇迹。但是中国的出口贸易增长态势并非一直顺利。2008年爆发的世界金融危机给中国出口贸易带来了巨大的负面冲击，这使中国意识到了外部金融市场对出口贸易影响的重要性，也察觉到了需要大力提升本土金融资本市场对企业出口贸易支持力度的紧迫性。

企业出口需要支付更多的固定成本和可变成本，所以出口企业容易受到融资约束的影响。本文从金融市场发展的角度切入，研究中国银行业竞争对企业出口的影响和作用机制。本文利用手工搜集的各地级市银行分支机构信息计算银行业竞争指数，并将其与2002-2013年的中国工业企业数据进行合并构造本文研究样本，采用面板回归与工具变量回归的方法实证检验中国银行业竞争对企业出口的影响和作用机制。研究得出以下结论：第一，中国地方银行竞争不仅有利于提升企业出口的概率，还有利于企业出口规模的扩张，对企业的出口强度也有一定的正向作用，该结论在选择合适的工具变量处理内生性之后依然稳健；第二，采用中介效应模型三步法对其机制检验发现，银行业竞争水平的提高能够缓解企业的外部融资约束进而利于企业出口，该结论不会因为外部融资约束指标计算方式的改变而发生变化；第三，我们在考察地方银行业竞争对不同企业的差异化影响时发现，银行业竞争对国有企业的出口依旧存在促进作用，银行业竞争水平的提高对国有企业的影响更像是“锦上添花”；而对民营企业的出口作用更像是“雪中送炭”，银行集中度的下降能够及时缓解民营企业的融资约束问题，并且其对民营企业出口的促进作用大于国有企业。此外，本文还发现地方银行业竞争水平的提高对高外部融资依赖度行业出口存在显著促进作用，对于低外部融资依赖度行业出口影响并不明显，对一般贸易企业的出口存在显著的积极影响，而对加工贸易企业出口影响不明显，东部和西部地区银行业竞争水平的提高对企业出口存在显著的促进作用而在中部地区则不明显。基于所得结论，论文从鼓励中小型银行发展，推动形成多层次、多元化的银行业竞争结构，审慎推进金融市场改革，以及做好监管工作避免金融风险等角度提出政策建议以期优化中国金融市场结构和满足广大企业的发展融资需求，提高企业出口竞争力进而促进企业出口。

在大力推进构建国内国际双循环相互促进的新发展格局与建设贸易强国的背景下，开展中国银行业竞争对企业出口的影响研究，对于中国在出口贸易面临国际环境不确定因素影响、传统比较优势渐失的紧张形势下有效发挥金融市场的关键作用进而保证出口稳增提质具有重要启示。

Since the reform and opening up, China's export trade has made remarkable achievements, especially for China's economic development. China's total export trade of goods increased 180 times from US $13.66 billion in 1979 to US $2499.482 billion in 2019, which is a miracle of the world. However, the growth trend of China's trade and export is not always stable. The huge negative impact of the world financial crisis on China's trade export in 2008 made China aware of the importance of the impact of external financial markets on trade export, and the urgency of the need to vigorously enhance the local financial capital market's support for its enterprises' trade export.

Enterprises need to pay more fixed and variable costs when they export, so export enterprises are vulnerable to financing constraints. This paper studies the effect and mechanism of the improvement of competition degree of Chinese banking on enterprise export. This paper uses the manually collected information of bank branches in various cities to calculate the banking competition index, and combines it with the data of China's industrial enterprises from 2002 to 2013 to construct the research sample of this paper, and uses the methods of panel regression and instrumental variable regression to empirically test the impact and mechanism of China's banking competition on enterprise export.

The research draws the following conclusions: first, the improvement of the competition degree of China's local banks is not only conducive to improving the probability of enterprises' export, but also conducive to the expansion of the scale of enterprises' export, and also has a positive effect on the export intensity of enterprises, and the conclusion is still robust after choosing the appropriate instrumental variables to deal with the endogeneity; second, the three-step method of intermediary effect model is adopted. Through the mechanism test, it is found that the improvement of banking competition can alleviate the external financing constraints of enterprises, which is conducive to the export of enterprises. This conclusion will not change when the calculation method of external financing constraints changes. Third, after investigating the differential impact of local banking competition on different enterprises, we find that banking competition still has a positive impact on the export of state-owned enterprises. At the same time, the export effect of that on private enterprises is more like "sending charcoal in the snow" that means the decline of bank concentration can timely alleviate the financing constraints of private enterprises, provide financing services, and promote their exports more than state-owned enterprises. In addition, it is found that local banking competition has a significant promoting effect on enterprises in industries with high external financing dependence, but has no significant effect on enterprises in industries with low external financing dependence, and has a significant positive effect on the export of general trading enterprises, but has no significant effect on the export of processing trade enterprises. Banking competition in eastern and western regions has a significant promoting effect on their enterprises It is not obvious in the central region. Based on the conclusions, this paper puts forward policy suggestions from the perspectives of encouraging the development of small and medium-sized banks, promoting the formation of a multi-level and diversified banking competition structure, carefully promoting the financial market reform, and doing a good job in supervision to avoid financial risks, so as to optimize China's financial market structure to meet the financing needs of the majority of enterprises, improve the export competitiveness of enterprises, and then promote the export of enterprises.

Under the background of promoting the construction of a new development pattern of domestic and international double cycle and building a powerful trading country, the study on the impact of competition of Chinese banking on the export of enterprises has important enlightenment on playing the key role of financial market to ensure the stable increase of export quality in the critical stage that China faces the interference of international environmental and the loss of traditional domestic comparative advantage.