Abstract: This paper establishes an analytical framework for the impact of trade intermediaries on the duration of enterprises' exports and empirically analyze the relationship between trade intermediaries and the duration of enterprises' exports by using the survival estimation method and the complementary log-log model based on matching the databases of China's industrial firms and China's import-export customs database from 2005 to 2014. This paper mainly examines the transmission mechanism of enterprises' export duration through trade intermediaries. It elaborates on the overall situation of Chinese enterprises' indirect and mixed export methods and the distribution characteristics of enterprises' export segments from a micro level, and empirically tests the impact of trade intermediaries on different export segment lengths of enterprises. In addition, this paper estimates the export risk rates of enterprises in the eastern region, enterprises in the central and western regions, foreign-funded enterprises and local enterprises respectively, and tests the export survival rates of enterprises in different regions and different ownerships respectively, so as to study the influence mechanism in depth and test it through the mediation effect model.
The empirical results indicate that after controlling other influencing factors of the duration of enterprises' exports, it is found that trade intermediaries can significantly reduce enterprises' export risks. Heterogeneity analysis shows that trade intermediaries have a positive prolongation effect on the export duration of enterprises of different regions and ownerships, but the significance of this effect varies. Specifically, the prolonging effect of trade intermediaries on enterprises in the eastern region is weaker than that in the central and western regions, the extension effect on foreign-funded enterprises is weaker than that of local enterprises, and the prolonging effect on enterprises with low market diversification level is weaker than that on enterprises with high market diversification level. By testing the mediation effect on the possible influence mechanism between trade intermediation and enterprises' export duration, this paper finds that exporting through trade intermediation enhances the level of export market diversification, which in turn improves the export survival rate, and is one of the key paths contributing to the positive effect of trade intermediation on enterprises' export duration.
The above conclusions imply that enterprises' export through trade intermediaries has played a positive role in promoting the continuation of the export duration of Chinese enterprises. Thus, attaching importance to the trade intermediary and correctly guiding the export enterprises is the key method to effectively improve the export problems of Chinese enterprise and give full play to the export continuity. For the government, it should moderately relax the restrictions on trade intermediaries, introduce corresponding policies to encourage the establishment and development of trade intermediaries, prompt more potential enterprises to grow into specialized trade intermediaries, and make full use of and give full play to the advantageous role of trade intermediaries. For enterprises, they should correctly recognize their strengths and weaknesses. Enterprises with no experience in exporting can consider cooperating with trade intermediaries to try to export and develop overseas markets. Enterprises that already have experience in exporting can expand the number of export markets through trade intermediaries, enter new export markets, improve the level of market diversification, diversify risks, and accumulate export experience in order to prolong the duration of enterprises' exports with higher efficiency.

Key words: Intermediary, Market Diversification, Enterprise Export Duration, K-M Survival Analysis

摘要： 本文建立贸易中介影响企业出口持续时间的分析框架,在匹配2005—2014年中国工业企业与海关数据库的基础上,采用生存估计法和补对数-对数模型,实证分析贸易中介与企业出口持续时间的关系。研究结果表明,在控制企业出口持续时间的其他影响因素后,贸易中介显著降低企业出口风险,有利于延长企业出口持续时间;贸易中介对不同地区、不同属性、不同市场多元化水平的企业出口持续时间都具有正向的延长效应并存在明显差异,即东部地区弱于中西部地区、外资企业弱于本土企业、低市场多元化水平弱于高市场多元化水平。进一步的机制检验分析显示,贸易中介主要通过促进出口企业市场多元化来提高其存活率,从而延长企业出口持续时间。

关键词: 贸易中介, 市场多元化, 企业出口持续时间, K-M生存分析