Abstract: With the rapid development of network information technology, modern logistics technology and emerging circulation formats, traditional specialized markets face new challenges from e-commerce models such as trading methods and trading technologies. Both theoretical observations and practical evidence show that the combination of offline channel and online channel is becoming the main feature and development trend of “new-type specialized market”. In the context of e-commerce, the information processing between business flow, logistics and information flow has experienced a qualitative leap. The traditional competitive market has gradually weakened its competitive advantage as a price center and distribution center, and even fell into the dilemma of "incompatibility between online and offline". Then, how will the specialized market evolve and whether it can be transformed and upgraded under the impact of e-commerce? Some scholars believe that although e-commerce has become one of the important factors to promote the differentiation, integration and upgrading of traditional specialized markets, online sales channels do not compress the profit margins of middlemen, and there are complementary advantages and coordinated interaction between online and offline channels. Another group of scholars believe that the advantages of e-commerce platform in terms of trading technology, trading methods, transaction efficiency, etc., have obvious substitution effects on the sales model and trading function of the specialized market, which has reignited scholars’ concerns about the "specialized market demise theory". The reason for this controversy is that most of the research is a case study or qualitative analysis of a few specialized markets or e-commerce platforms, and only analyzes the alternative relationship or benefit between the professional market and the e-commerce platform from a macro or meso-level. However, previous studies have not revealed the micro-mechanism of the specialized market participants in the e-commerce environment to choose the strategy of offline and online channels, and have not carried out quantitative analysis, which leads to the lack of universal significance in most conclusions. It should be pointed out that the rapid development of e-commerce has provided a new distribution and procurement channel for market participants, which has promoted the transformation of the specialized market from “seller market” to “buyer market”.
This paper constructs a strategy selection model for line and online channels of specialized market operators, and uses the questionnaires of Yiwu Small Commodity Market to do empirical analysis. Research shows that substitution effect, recovery rate, policy support, production scale, market transaction efficiency and economic agglomeration are important factors influencing the choice of specialized market operators. In response to the above theoretical analysis, the author conducted a questionnaire survey on the market operators, in Yiwu Small Commodity Market, and distributed 450 questionnaires and 445 valid questionnaires, with an effective rate of 98.9%. The results of the questionnaire analysis show that: (1) The improvement of substitution effect and recovery rate has a significant promoting effect on the market performance of market operators. Moreover, the faster the market share of the online channel is selected by market operators, the higher the market performance is, which indicates that the improvement of the recovery rate further enhances the substitution effect of the online channel on the offline channel. (2) Policy support, especially the construction of specialized market information infrastructure by local governments has improved the market performance of market operators. The local government’s policy support has further reduced the operating costs of online channels selected by market operators and improved the market transaction efficiency of online channels. (3) The expansion of production scale will help improve the market performance of business operators. This also verifies the dependence of the market operators on the “Yiwu Commercial Circle”, that is, it is precisely because Yiwu Small Commodity Market is the main body that forms a cross-regional division of labor cooperation network with increasing returns to scale, which enables the market operators to obtain higher market performance. (4) Late-joined market operators will face higher opportunity costs than early-joined market operators. Further research found that the recovery rate of early-joined market operators has a significant effect on market performance, while the relationship between the recovery rate of late-joined market operators and market performance is not significant. This shows that early-joined market operators can expand their market share or market performance faster through online channels, which also proves that the late-joined market operators will face higher opportunity costs. In addition, for the late-joined market operators, the expansion of production scale and economic agglomeration effect are important sources of market performance improvement. For the early-joined market operators, improving market transaction efficiency has a significant positive impact on increasing market performance. This means that the integration of online and offline channels is the main way for the sustainable growth of market performance.
The above research conclusions provide some policy implications for how to develop e-commerce in specialized markets. First, build an industrial division of labor network based on market characteristics and product classification. While promoting the large-scale development of the specialized market, it should also promote the development of related industries according to the characteristics of the trading group, product attributes and differentiation, so as to provide industrial support for the economies of scope and economies of scale of the specialized market. Secondly, improve the support service system for the integration of offline channels and online channels. In the process of promoting the integration of dual channels, we should accelerate the development of modern service industries such as financial services and information services closely related to e-commerce, and promote the information development of market operators and governments, banks and intermediary organizations. In particular, the Internet of Things (IOT) system is compatible with the virtual market and the physical market to enhance the market performance of dual channel integration. Finally, the specialized market needs to improve the market trading system and market trading functions through institutional innovation. Local governments should respect the objective development rules of specialized markets and e-commerce, and continuously optimize the trading system and trading features of specialized markets by improving high-quality management services, efficient trading methods, perfect supporting facilities, safe credit systems, and high-quality commodity systems.

Key words:  e-commerce, specialized market, strategy choice, questionnaire