关键词: 国际友好城市, 出口促进效应, 非正式制度, 风险抵抗, 二元边际

Abstract: As an important supplement to formal agreements and institutional arrangements，the establishment of international twin cities has strengthened trust and indepth communication between cities，becoming an important catalyst and booster for international economic cooperationBased on the perspective of foreign trade highquality development，this paper examines the impact of the“circle of friends”formed by international twin cities on the export trade between cities using the data of matching pairs between 287 Chinese cities and 136 countries or regions in 20022015The results find that： （1）The agreements of international twin cities have significantly promoted the export volume and export value of Chinese cities by 100% and 116% respectively（2）The trade promotion effect of international twin cities is more derived from trade creation rather than trade transfer（3）In addition to affecting exports by intensive margins，international twin cities have also promoted the expansion margins of exports in terms of the number of product types and the proportion of hightech industries（4）With SARS and the global financial crisis as incident impacts，the agreements of international twin cities has strengthened the ability of Chinese cities to resist risks in exports（5）The results of heterogeneity analysis show that the agreements of international twin cities have more obvious export promotion effect on nonBelt and Road countries and geographically adjacent countries in ChinaThe above results are supported by a series of robustness testsThis paper is of great value to comprehensively understand the economic connotation of international twin cities and to explore new paths for highquality development of international trade

Key words:  , international twin cities； export promotion effects； informal institutions； risk resistance； dual margins