On 4 June 2021, the 12th session of the " Xixian Forum on Income Distribution and Modern Finance", co-organized by the School of Public Finance and Taxation and IIDPF, was successfully held in 603 Wenquan Building. Professor Cui Xiaoyong of Peking University, as the keynote speaker of the forum, delivered a keynote speech entitled Optimal Tax Theory Research: Methods and Applications. The forum was chaired by Professor Zhang Kezhong, Dean of the Institute of Public Finance and Taxation and Vice Director of IIDPF. Professor Lu Yuanping, Executive Vice Director of IIDPF, Professor Guo Yuemei of the School of Public Finance and Taxation, Professor Wu Lei, IIDPF Researcher, Professor Tian Binbin, Associate Professor Zhao Ying and around 30 faculty and students attended the forum.
Professor Cui Xiaoyong presented on preparatory knowledge, the optimal tax research framework and methodology, and the Ramsey-Diamond-Mirrlees-Atkinson-Stiglitz framework and its application. In reviewing the basics of optimal taxation theory with the audience, Professor Cui noted that the essence of taxation is to change prices, and changes in prices bring about changes in individual or corporate behaviour such as consumption, labour supply and savings, so the relationship between behaviour and prices is the basis for the study of taxation. Professor Cui then gave a detailed analysis of the four stages of taxation theory: the first generation of public finance theory (commodity tax, static + linear taxation), the second generation of public finance theory (labour income tax, static + non-linear taxation), the third generation of public finance theory (capital income tax + labour income tax, dynamic + linear taxation), and the new public finance theory (capital income tax + labour income tax, dynamic + non-linear taxation). labour income tax, dynamic + non-linear taxation).
Based on the years of experience in tax theory research, Professor Cui Xiaoyong provides an in-depth analysis of the Ramsey-Diamond-Mirrlees-Atkinson-Stiglitz framework for optimal tax theory research. Specifically, the Ramsey problem, the Diamond-Mirrlees model, and the Atkinson-Stiglitz framework are each explained in detail. At the end of the forum, Professor Cui introduced the practical application of optimal taxation theory, using inter-regional insurance and transfer payments, dynamic transfer payments and inter-regional insurance, and widening wage income gap and optimal taxation as examples.
Professor Cui Xiaoyong concluded his speech with a summary of his experience on optimal tax theory research. Addressing the students in the audience, Professor Cui expressed the importance of not being intimidated by tax theory research and treating the relevant research literature as an interesting book to slowly develop one's research interest. After the presentation, the audience had an interactive session with Professor Cui Xiaoyong. Professor Cui gave detailed answers to all the questions raised. The content of Professor Cui Xiaoyong's speech and his clear research ideas were of great reference value and significance, which inspired the students and faculty present.