开发区政策有利于促进当地企业出口参与吗——基于双重差分方法的验证

Does Development Zone Policy Promote Local Firm’s Export Participation——Based on the Difference-In-Difference Method Test

本文探讨了国家级开发区(包括经济技术开发区和高新技术产业开发区)的设立对城市企业出口参与的影响,基于Melitz (2003)模型,将企业出口固定成本内生化,得出集聚经济有利于降低出口固定成本,提高企业进入出口市场概率的结论。同时利用2000-2014年204个地级市层面的面板数据,采用双重差分方法对政策导向型的开发区集聚经济是否促进当地企业出口参与的效果进行了实证检验,研究结果表明:在控制了城市的经济变量、时间效应和地区效应后,国家级开发区的设立能够使城市每年出口企业数量的增长率显著增加15. 7%;进一步考察这种政策效果的时效性,发现国家级开发区在促进企业出口参与上的政策效力随时间呈倒U型趋势,并在实施后的第3年达到最大,开发区政策对企业出口参与的推动作用至少持续3至4年;基于倾向得分匹配(PSM)法的变换处理组检验结果证明开发区政策显著促进了企业的出口参与,且这种因果关系的安慰剂检验结果在不同的估计方法和估计步骤下均保持稳健。

This paper is focused on the promotion impact of the establishment of National-level Development Zone( Economic and Technological Development Zone and High-Tech Industrial Development Zone) on city-level firm’ s export participation. In the theoretical part,we introduced endogenous thought of firm’ s fixed export cost on the basis of Melitz( 2003) model,deducing that agglomeration economies reduced fixed export cost and increased the probability of firm’ s entering export market. Then,we used DID method to conduct the empirical test towards the above questions by referring to a balanced panel data of 204 prefecture-level cities in 2000-2014 after passing the quasi-experiment test and parallel trend test. The results show that: The establishment of Nationallevel Development Zone significantly raises the city-level annual growth rate of the mass of exporters by 15. 7%;Considering the timeliness of the policy,the National-level Development Zone has seized an inverted U-shape impact over time on prompting firm’ s export participation which reaches the peak in the third year after the experiment,and this promotion effect can last for at least three to four years;The "Switching Treatment Group Test"based on PSM method proves that just the development zone policy has significantly prompted firm’ s export participation,and the result of this causality "Placebo Test"is robust regardless of different estimation methods and procedures.