Progress and prospect of research on regional effect of variety

The relative importance of regional specialization and diversity has been under constant debate in the field of economic geography. At present, China has entered a period of transformation and upgrading, changing its economic growth momentum. It is necessary to understand and evaluate the spatial effect of industrial diversity in order to choose a reasonable path for regional development. In view of the internal relationship between industries, evolutionary economic geographers divided diversity into related variety and unrelated variety according to the degree of correlation between industries, which provide a new analytical framework for explaining the internal mechanism of regional economic effect of variety. This article summarized the concepts and measurement methods of variety, and discussed the relationship between different types of variety and regional economic development and its internal mechanism. Through a literature review, it is found that related variety and unrelated variety play an important role in improving regional productivity, resisting external shocks and maintaining stability, and promoting employment, innovation, and other aspects through knowledge spillover and portfolio effect, but the process is relatively complex. Considering industrial characteristics, regional scope, location, development stage, and other factors, there is a nonlinear relationship between variety level and regional growth. It is proposed that the focus of future research should begin from the following aspects: 1) Expand the meaning of relatedness to define variety in a broader sense and further consider the role of the relatedness of other factors, such as market and institutional variety, in the spatial effects of regional variety, while not only limiting it to similarities but also taking into account complementarities. 2) Further examine how firms and actors at the micro level discriminate and absorb knowledge from related and unrelated industries, and how multiple forms of proximity affect the knowledge restructuring process in related and unrelated domains. 3) Fully consider the characteristics of regional heterogeneity and the scope and conditions of regional variety at different temporal and spatial scales to provide theoretical support for the effective implementation of policies in different administrative divisions. 4) Existing studies are mostly based on the experience of Western countries, lacking an overall assessment of related and unrelated diversities in China and its pattern of change over a long period of time. It is necessary to take full account of the institutional contexts of different countries in order to further deepen and complement the theoretical framework and research results of evolutionary economic geography.