Authors: Zeng Gang, Teng Tangwei, Cao Xianzhong Inter-regional cooperation and enclave economic growth in development zones in the Yangtze River Delta started early in the country and achieved remarkable results. From north-south docking in Jiangsu Province, and inner-coastal areas cooperation in Zhejiang Province, towards cooperative development of parks across the administrative boundaries of provinces and cities, about 20 years have passed. In the past 20 years, typical cases have emerged in the Yangtze River Delta region, such as Shanghai Caohejing Development Zone (Haining Sub-zone) and Shanghai Shibei High-tech Nantong Science and Technology City, serving as an important way to strengthen regional cooperation and joint development. Shanghai Lingang-Suzhou Industrial Park cooperative development and management model, Shanghai-Jiangsu Dafeng Industrial Linkage Cluster, Shanghai Caohejing Emerging Technology Development Zone (Haining Sub-zone), China-Singapore Suchu Modern Industrial Cooperation Park, China-Singapore Jiashan Modern Industrial Cooperation Park and other inter-provincial  cooperation parks were included in the “Outline of Regional Integrated Development Plan for the Yangtze River Delta”. The Outline identified that the region will explore cooperation modes such as the joint construction of cooperation parks, jointly expand development space, and orderly promote the transfer of industries across regions and the two-way flow of production factors. In the context of regional integration in the Yangtze River Delta, the enclave economy has shown a trend of shifting from an “industrial enclave” to an “innovation enclave”, and the construction of an “innovation enclave” has become an important way for interregional cooperation in the Yangtze River Delta. In recent years, there has been a new trend of “innovation enclaves” in the Yangtze River Delta region. There are more and more “reverse enclaves” or “two-way enclaves”. That is to say, the cooperation between Zhejiang/Jiangsu and Shanghai involves a variety of “innovation enclaves” in terms of talent, technology, and industrial incubation. First, the “enclaves” show a trend of reversal, that is, the low-gradient areas take the initiative to establish “reverse enclaves” in high-gradient areas. In 2019, Jiashan County, Zhejiang Province established the Jiashan International Innovation Center in Shanghai, guiding Jiashan high-tech companies to set up R&D centers in Shanghai, creating a Shanghai-Jiashan collaborative innovation model of “front desk in Shanghai, back office in Jiashan” and attracting high-quality start-up projects that originated in Shanghai or overseas to settle down in the incubator. These projects were transferred to Jiashan for industrialization after maturity, realizing the industrial collaborative innovation model of “incubation in Shanghai and industrialization in Jiashan”. Currently, Shanghai University Composite Materials Research Center, Tuya Smart, Dtwave, and Israel’s Startup East China have signed contracts and settled in Jiashan County. In addition, Zhejiang Province’s Quzhou, Cixi, Huzhou, and Chun’an have also established “innovation enclaves” in Shanghai and Hangzhou.     Second, the “enclaves” show a two-way trend, that is, “two-way enclaves” are set up between low-gradient and high-gradient areas. In the past, Shanghai established “industrial enclaves” in other provinces and cities. However, with the deepening of the Yangtze River Delta integration strategy, some cities with strong economic power and R&D needs took the initiative to set up “enclaves” in Shanghai, thus initiating the “two-way” mode.     In 2018, while Shanghai set up the “Demonstration Zone for the Deep Integration of Advanced Manufacturing Industry (Jiading Industrial Zone Wenzhou Park)” in Wenzhou City, Zhejiang Province, Wenzhou also established a “Science and Technology Innovation (R&D) Park” in Jiading District, Shanghai, under which the scientific and technological innovation resources in Shanghai were seamlessly connected with the advantages of Wenzhou’s advanced manufacturing industry.     In 2019, Jiashan County, Zhejiang Province established the Jiashan International Innovation Center in Shanghai, and the Jiashan County Government established the first-phase angel fund of 50 million yuan for the “enclave”. Enterprises that settle in can receive a maximum of 1.5 million yuan in funding, together with a maximum of 100,000 yuan annually in interest discount of technology bank loans, and innovation coupons of up to 300,000 yuan.     Third, these “enclaves” showed diversification, that is, the diversification of development and operation mechanisms and management models. According to the different leaders, the “innovation enclaves” in the Yangtze River Delta can be divided into four types: centrally-led, local government-led, park-led, and enterprise-led. According to the different dominant regions, they can be divided into those led by enclaves, exclaves, co-management mode, and multi-level participation. Most of the “innovation enclaves” built by Zhejiang in other provinces and cities in China are enterprise-led and co-managed by both parties, mostly in the form of R&D centers. For example, Wenzhou City, Zhejiang Province invested in the construction of a “Science and Technology Innovation (R&D) Park” in Jiading District, Shanghai, and Jiashan County, Zhejiang Province invested in the construction of the Jiashan International Innovation Center in Shanghai. The “innovation enclaves” built in Zhejiang by Shanghai, Jiangsu and other provinces and cities are mostly led by industrial parks and co-managed by both parties. For example, Shanghai has invested in the newly built Shanghai Caohejing Emerging Technology Development Zone (Haining Sub-zone), and Wenzhou Park of Jiading Industrial Zone (advanced manufacturing in-depth integration and development demonstration zone). Fourth, the “enclaves” present specialization and high density and concentration. In the past, the “enclaves” mostly had the characteristics of large areas, diversified industries, and extensive development. However, the current “innovation enclaves” have small areas and are mostly operated through incubators and innovation platforms, and focus on a specific high-tech industry for intensive development, showing obvious characteristics of specialization, high density, and high concentration.     For example, as an important carrier for Zhejiang to implement the “innovation enclave” policy and promote mutual benefit and win-win results between regions and cities, the long-term planning of Zhejiang Talent Building covers an area of approximately 70 acres with a total planned construction area of 175,000 square meters, which is mainly used for cities in the province to introduce and build corporate R&D headquarters and innovation centers so as to gather multiple “innovation enclaves”. Jiashan City set up the Jiashan International Innovation Center in Shanghai Hongqiao Business District, which has a total area of 17,000 square meters. Some industrial enclaves are relatively larger and scattered. For example, the planned area of Shanghai Caohejing Development Zone (Haining Sub-zone) is 15 square kilometers, and the planned area of Shanghai-Jiangsu Dafeng Industrial Linkage Cluster is 33 square kilometers.     In addition, innovation enclaves have also promoted economic and technological cooperation between cities in the Yangtze River Delta. As of December 2018, the industrial transfer base of Shanghai Caohejing Development Zone had facilitated a total of 111 industrial transfer projects, with a total amount of 96 billion yuan. The park has established a data sharing cloud platform covering more than 200 development zones across the country, which has become a driver to push forward a strong bond of social and economic cooperation and interaction between the east and the west regions. According to data released by Zhejiang Online, as of the end of May 2018, Quzhou Haichuang Park had 164 investment projects, including 75 industrial projects, with a total registered capital of 546 million yuan. Nine projects were registered in Quzhou with a total investment of 1.8 billion yuan. There were a total of 89 fund projects with a total registered capital of 5.605 billion yuan, and fund management scale of 5.529 billion yuan. Sixty-one funds were registered in Quzhou with management scale of 4.428 billion yuan, achieving remarkable innovation results. ?