The central government has repeatedly emphasized that the Hong Kong Special Administrative Region’s integration into national development is not only a natural extension of the “one country, two systems” framework but also the key to unlocking new directions, new spaces, and new momentum for the city’s future socioeconomic development.

Since late 2022, Chief Executive John Lee Ka-chiu has personally overseen Hong Kong’s efforts to align with national plans, including the 14th Five-Year Plan (2021-25), the Guangdong-Hong Kong-Macao Greater Bay Area, and the Belt and Road Initiative. These efforts have injected fresh impetus into Hong Kong’s development.

The HKSAR government currently operates five offices and 11 liaison units across the Chinese mainland, maintaining close ties with provincial and municipal governments to promote high-quality regional and national development. But to truly integrate into the national agenda, Hong Kong must first deepen its integration into the Greater Bay Area; and within the Greater Bay Area, its closest partner is Shenzhen.

Hong Kong and Shenzhen share geographic proximity and cultural affinity. Yet their development trajectories and institutional frameworks differ significantly, offering fertile ground for complementary collaboration.

The economic systems of the twins are distinctive — with Hong Kong operating under a capitalist free-market economy while Shenzhen features a socialist market economy.

Under the “one country, two systems” framework, Hong Kong retains its common law legal system, independent Judiciary, and autonomous financial and trade policies. Meanwhile, Shenzhen benefits from its status as a national special economic zone and enjoys policy flexibility as a coastal city with direct land border access to Hong Kong, which, in my opinion, demonstrates the institutional advantages of the duo working together.

In terms of demographics, the two cities complement each other. The HKSAR is predominantly a city of locals with less than 15 percent of its population being new immigrants, while Shenzhen is famous for being a “city of newcomers”, with over 84 percent of its population being migrants from elsewhere in the country. The two cities also differ in their age profiles: Hong Kong is aging while Shenzhen is youthful.

Regarding governance philosophy, Hong Kong practices “small government”, whereas Shenzhen’s “big government” model allows for stronger policy execution. Thus, the two uphold different philosophies in pursuing development. The former’s growth has historically been reactive, shaped by external opportunities. The latter, by contrast, has pursued proactive innovation and reform since the establishment of the Shenzhen Special Economic Zone in 1980.

A comparative analysis of GDP structures between Hong Kong, Shenzhen, and Singapore shows that a combined Hong Kong-Shenzhen economy closely resembles that of Singapore. This economic complementarity forms a solid theoretical foundation for deeper integration.

To capitalize on this synergy effect between the neighboring cities, the author proposes the creation of a “Hong Kong-Shenzhen Deep Cooperation Development Zone” along both banks of the Shenzhen River, encompassing the Lo Wu, Man Kam To, and Liantang/Heung Yuen Wai border areas. This zone would be jointly developed under the concept of “one river, two banks; one zone, two governments”.

Mainland residents would enter this envisioned zone without formally exiting the mainland, and Hong Kong residents and foreign nationals would similarly enter without leaving Hong Kong. Companies could register dual entities — one in Shenzhen and one in Hong Kong — each with accounts in renminbi, Hong Kong dollars, and foreign currencies. This arrangement would allow pre-approved cross-border capital flows and currency exchanges, facilitating outbound and inbound investments.

Multinational corporations could allocate different departments across the two jurisdictions based on functional needs, optimizing operational efficiency.

This model effectively transforms parts of Hong Kong into enclaves of Shenzhen, and vice versa. While jurisdictional, planning, and tax-sharing issues require further study, the concept opens the door to unprecedented cross-border collaboration.

The zone would enable seamless movement of people, vehicles, goods, capital, data, talent, technology, and even biological materials. Simplified ICQS (immigration, customs, quarantine, and security) procedures would ensure efficient cross-border operations.

This “brackish water” institutional ecosystem — where two systems meet and blend — could foster a unique economic biosphere.

The Greater Bay Area currently features four major cooperation platforms: Qianhai, Hengqin, Nansha, and Hetao. Each has distinct strategic roles, governance models, and industrial focuses.

The proposed Lo Wu/Northern Metropolis zone would become the fifth cooperation platform, complementing the existing four and collectively driving the Greater Bay Area toward becoming a world-class bay area economy.

The author is a member of the Chief Executive’s Policy Unit Expert Group and chairman of Doctoral Exchange, a Hong Kong-based think tank.

The views do not necessarily reflect those of China Daily.