Evolution Of Water Treatment Industry In Yixing City From Complex Network Perspective

Yixing city, having the reputation of "the environmental protection industry town", has recently experienced development bottleneck in its environmental industry. Some technological and economic issues have been extensively discussed in qualitative ways, such as product innovation, industrial organization and marketing capability. However, a more quantitative and holistic framework is required to deal with the highly interwoven issues for industrial upgrading. Complex network, an emerging tool on complexity, is introduced here to establish such a framework to explore the evolution of water treatment industry in Yixing.Firstly, data and information required for network establishment, including products, processes and organizational information, were collected from surveys of 240 enterprises and field investigation of nearly 80 enterprises. Preliminary statistical analysis shows that Yixing's water treatment industry has experienced three major phases, that is, the pregnant period (1976-1985) with slow increasing of both enterprises and product categories, the accelerating period (1986-1996) with continuing increasing of both enterprises and product categories, and the adjustment period (1997-2005) with high increasing of products category but slow increasing of enterprises.Secondly, evolutionary network (1976-2005) of water treatment industry was established and visualized, followed by analyzing network topological properties, such as network centrality, hierarchical structure and evolutionary paths. The results show that Yixing's water treatment industry presents the small-world and scale-free properties. With the growth of network, the products are observed to reveal the preferential attachment. The products with highest centrality are: single equipment that involves water cooling equipment and aerobic treatment equipment for sewage; series or sets of equipments, including water supply, sewage treatment and general waste water treatment equipments; and some kinds of projects, like waste water treatment projects in steel industry and power plants. The main evolutionary path is identified as follows: water cooling equipment, desalting equipment→general water supply equipment→aerobic treatment equipment for sewage→general waste water treatment equipments, especially sets of those for power plant and coal industry→chemical deposition equipment for industrial waste water treatment→industrial waste water treatment projects→investment and financing for water treatment projects.Finally, based on subgroup analysis of enterprise-product affiliation network series from 1976 to 2005, the evolutionary process of water treatment industry in Yixing City was discussed, generally on product distribution. During the evolution of water treatment industry in Yixing City, product portfolio within enterprises focused on the products occupying central position in the evolution network; and the coincidence degree of products among different enterprises kept growing. In more than 50% enterprises surveyed, at least half of the categories of their main products were exactly the same till 2005. Research shows that complex network could offer standardized tools to study evolution of regional industries.