This collection of essays presents insight and methodology that are highly relevant for readers today as they consider the future of the world they live in. Experiencing the COVID-19 pandemic, people have realized how fragile the current economy is and the necessity for reconstructing the socio-economic system. That system, which was considered the default for so long, was succeeded by the analytical framework of economics and regional science. The contents of this book are diversified, as are the achievements of Prof. Yasuhiro Sakai, to whom this volume is dedicated, and cover a wide area from mathematical and experimental economics to conventional and emerging fields of regional science. Some are timeless topics that have had new life breathed into them.

Part I deals with, among other areas, risk management with uncertain events; the effectiveness and impacts of regulation and friction related to trading; the stability of strategic behavior and market equilibrium; and sustainable regional development and urban planning from the long-term perspective. Part II also presents a diversity of subjects, including input-output analysis and computable general equilibrium (CGE) modelling for internal as well as external structure and network linkage, such as a value chain; openness and creativity as related to competition among cities and regions; dispersion versus concentration; and inequality versus equality.

Masamichi Kawano is a Professor Emeritus of Kwansei Gakuin University, Nishinomiya city, Japan. He earned Ph.D. from University of Tsukuba. The field of the thesis is public economics, especially, optimal taxation in dynamic framework. He has taught Economics at Toyohashi University of Technology, Teikyo University of Technology and Kwansei Gakuin University, etc. He is now teaching economics as a Guest Professor at the School of Science, Kwansei Gakuin University. His fields of interest are applied microeconomics, theoretical regional economics, etc. He has been a member of the Regional Science Association International.

Karima Kourtit is at the Open University, Heerlen, The Netherlands. She was lab-owner at the Jheronimus Academy of Data Science (JADS) of the division Smart Cities & Data analytics (owned by the Eindhoven University of Technology and Tilburg University), 's- Hertogenbosch, The Netherlands. She has worked at the Center for the Future of Places (CFP) of the Department of Urban Planning and Environment, School of Architecture and Built Environment at KTH Royal Institute of Technology, Stockholm, and Adam Mickiewicz University, Poznan, Poland. She holds two Ph.D.s, in both economics and geography (with distinction), and has a profound interest in regional and urban topics. Her research interest focuses on the emerging 'New Urban World'. Her main scientific research is in the field of creative industries, urban development, cultural heritage, digital technology, and strategic performance management. Lately, she has also been involved in the implementation of several national and international research projects and initiatives. Furthermore, she has been an editor of several books and guest editor for many international journals, and has published a wide array of scientific articles, papers, special issues of journals and edited volumes in the field of geography and the spatial sciences. She is also managing director of The Regional Science Academy. In summary, her academic profile is characterized by a profound involvement in evidence based urban and spatial research on smart city policy and data metrics, by a strong commitment to educational support to young researchers and by an active role in many international scientific and managerial activities.

Peter Nijkamp is emeritus Professor in regional and urban economics and in economic geography at the VU University, and associated with The Open University of the Netherlands (OU), Heerlen (The Netherlands), Alexandru Ioan Cuza University of Iasi, Iasi (Romania), Royal Institute of Technology (KTH), Stockholm (Sweden), University of Technology, Benguérir (Morocco) and A. Mickiewicz University, Poznan (Poland). He is member of editorial/advisory boards of more than 30 journals. According to the RePec list he belongs to the top-30 of well-known economists world-wide. He is also a fellow of the Royal Netherlands Academy of Sciences, and past vice-president of this organization. He has served as president of the governing board of the Netherlands Research Council (NWO). In 1996, he was awarded the most prestigious scientific prize in the Netherlands, the Spinoza award.

Yoshiro Higano, Ph.D. in Environmental Science, Hokkaido University, is emeritus Professor in environmental policy and planning at University of Tsukuba. He has served as Executive Secretary of the Pacific Regional Science Conference Organization of the Regional Science Association International (RSAI), President of the Japan Section of RSAI, and President of RSAI. His research interest is in comprehensive evaluation of environmental remediation technology and environmental policy, regional sustainable development strategy, definition and measurement index of agglomeration and Marshallian type of externality, location decision analysis, and impact of ICT and AI technology development on urban formation. He is Editor-in-Chief of Asia-Pacific Journal of Regional Science.