Following the opening ceremony of "Intelligent Decision-making and Gaming Conference Series" (Online Conference) and the keynote report of Academician YANG Shanlin's Conference on the morning of July 15th, 2020, the first thematic sub-forum of this series of seminars was successfully held on the morning of July 16th in the manner of Tencent conference. This special sub-forum is co-organized by the School of Economics and Management of Beijing Jiaotong University. Professor CAO Zhigang, Vice President of intelligent Decision-making and Game Branch, organized and presided over the meeting, which theme is "Social and Economic Network Analysis". The forum invited ZHANG Boyu, the winner of the National Natural Science Foundation for Outstanding Youth and an associate professor from Beijing Normal University，Professor LI Sanxi of Renmin University of China, winner of the Yangtze River Youth Foundation of the Ministry of Education and Outstanding Youth Foundation of the National Natural Science Foundation of China, Professor YU Ning, Executive Dean of the Institute of Social and Economic Studies, Nanjing Audit University, who made speeches, Professor SUN Ning, Distinguished Professor of Cheungkong Scholars and Dean of the Institute of Social and Economic Studies, Nanjing Audit University, who made guest comments. The main venue of the special sub-forum and the live broadcast sub-venue attracted the enthusiastic participation of more than 400 listeners from all over the country, and the response was very good.

At the beginning of the meeting, Professor LI Dengfeng, President of the Intelligent Decision-making and Game Branch, delivered an opening speech on behalf of the branch on the opening of this special sub-forum. Chairman LI Dengfeng introduced the Chapter of Intelligent Decision-making and Game and the outlines of this seminar series, expressing warm congratulations on the opening of the sub-forum and highly appreciation and encouragement for the organization of the sub-forum, he also introduced the importance of academic communications of scientific research from personal experiences.

Professor ZHANG Boyu's report is entitled "Coordinated Games on the Internet". The network coordination game has been widely used in public opinion communication, voting and group decision making. In the report, Professor ZHANG Boyu introduced some of the research results of his and his collaborators’ in the field of the network coordination game. They first considered a coordinated game model of homogeneous groups on the network by using the theory of the ancestor, the stochastic stable equilibrium of game under different updating processes such as imitation and optimal response were compared, and the relationship between risk-dominant equilibrium and stochastic stable equilibrium were analyzed. On this basis, the coordinated game model of heterogeneous groups on the network was further considered. Based on the optimal reaction updating process, the stability of different equilibria and the size of the attraction domain were analyzed by using the stochastic differential equation method. The results showed that lower network homogeneity index was helpful for heterogeneous groups to achieve coordination.

Professor LI Sanxi’s report was entitled "Consumer Search Theory in the Information Age". Professor LI Sanxi conducted a systematic review of consumer search theory, emphatically introducing how to promote the advanced development of consumer search theory with the development of information technology: Searching cost reduction, non-random search model, and the core role of platform in search theory. Based on several research articles on consumer search, Professor LI Sanxi put forward the prospect of consumer search theory in the future.

Professor YU Ning's report was entitled "Game and Measurement Identification in Social Networks". In the report, Professor Yu Ning introduced two working papers on measurement identification based on incomplete information games in social networks "Adjusting for Peer-Influence in Propensity Scores When Estimating Treatment Effects"(with Mathew Jackson and LIN Zhongjian), "Uncovering Heterogeneous Social Effects in Binary Choices"(with TANG Xun and LIN Zhongjian). The former was game modeling for the group selection of the control group and the control group in the social network, in which a Peer-Influenced Propensity Score Matching(PIPSM)method was proposed to solve the endogeneity problem caused by group selection . The latter built model of the game of interaction within a small group, trying to identify and estimate the heterogeneous peer effect and situational effect based on the selective information in the absence of social network information.

As the last part of the forum, the special guest Professor SUN Ning made excellent comments on the reports of three speakers. Professor SUN Ning first highly affirmed the academic level of the three speakers and the advanced nature of the report, and then had a heated discussion with the speakers on some technical details in the report. The special sub-forum came to a close after professor CAO Zhigang's brief summary.

It was reported that this seminar series started from July 15th to the end of September, consisting of three conference theme reports and three thematic sub-sessions/thematic forum reports. Director LI Dengfeng invited relevant researchers from all over the country to pay close attention to the follow-up academic reports of "Intelligent Decision-making and Gaming Conference Series".