# Network Structure and Synergy Characteristics in the Guangdong-Hong Kong-Macao Greater Bay Area
## 1 Introduction  
World Bank statistics indicate that 75% of the world's economic activity originates from port and bay areas and their surrounding hinterlands. The Global Cities Index Report 2023 highlights that most of the top thirty cities globally are situated in bay areas, signaling the onset of a Bay Area era. Globalization is driving regional economic integration, which is becoming a vital strategy for countries and regions to foster economic growth. The Guangdong-Hong Kong-Macao Greater Bay Area (referred to as the \"Greater Bay Area\") is one of China's fastest-growing and most dynamic regions, serving as a strategic tool for promoting reform, opening up, and deepening regional cooperation. The release of the Outline of the Greater Bay Area Development Plan signifies rapid progress and the elevation of its development to a national strategy. The economic interdependence within the Greater BayArea extends beyond city interactions to global economic connectivity. The development and modernization of the transportation system are critical for regional economic growth, directly influencing resource flow, production factor allocation, and market exchanges. Improved transportation significantly reduces physical distances between cities, enhancing the frequency and efficiency of economic activities. Successful examples demonstrate that integrating infrastructure and liberalizing factor flows are essential prerequisites for Bay Area economic development. These elements provide the foundation for deep integration and the creation of a synergistic economic system in the Greater Bay Area [1]. In the context of globalization and localization, regional development has become a central focus in modern economic research. The intersection of geography and economics highlights that transportation development is a crucial link between regions, directly influencing interregional economic interactions and overall growth. The importance of transportation and economic linkages is particularly evident in city clusters and bay regions. Interregional transportation infrastructure significantly affects the emergence and growth of cities, while urban transportation systems impact their size and scope [2]. City clusters are concentrated organizational units within specific geographic areas, primarily influenced by one or more prominent cities. These clusters are interconnected with surrounding regional economies through compact spatial patterns, strong economic ties, and well-developed infrastructure [3; 4]. The development of city clusters relies on efficient transportation networks. Notably, the level of economic integration and the fulfillment of regional functions are closely linked to the connectivity and operational efficiency of transportation systems within specific clusters, such as those in the Bay Area. Cross-border flows of capital, information, cargo, and labor are accelerating, marking a transition in the global economy from the physical concentration of the industrial age to the networked distribution of the information age [5; 6]. Traditional geographic space is being compressed by virtual environments and mobile time. The global economic system now embodies a \"mobile economy\", where conventional urban patterns converge with flow space, creating a distributed functional space centered around networks. This evolution poses challenges for traditional spatial studies in geography and sociology, which struggle to account for the social impacts of virtual space and network flows. Flow-space theory is crucial for understanding economic activities and network dynamics in this globalized context [7]. Consequently, the research paradigm for regional spatial structure shifts from static to dynamic perspectives, emphasizing the multidimensionality of structures, including information, transportation, capital, technology flows, and functional linkages.