Research on the Dynamic Evolution, Regional Differences, and Convergence of Commodity Market Segmentation in China

This paper uses manually collected data on the consumer price index of eight commodity categories from 281 Chinese cities spanning the years 2001 to 2021 to measure the Commodity Market Segmentation Index (CMS) by the relative price method. The analysis incorporates Kernel density estimation, the Dagum Gini coefficient, and convergence models to examine trends, regional disparities, sources, and the presence of σ convergence and β convergence within the Chinese commodity market. The findings reveal the following: ① At both the national level and across four economic regions, a discernible trend has emerged indicating a decline in the CMS. ② Although the national market demonstrates integration, significant regional disparities persist within China. The primary contributor to these disparities is the overlapping density in the CMS, accounting for 49.05%. ③ Convergence models suggest that the CMS at the national level, as well as in the Eastern and Central regions, exhibits temporal fluctuations. Notably, no significant σ convergence is observed. Conversely, in the Western and Northeast regions, dispersion initially increased before subsequently decreasing, with the final dispersion value being significantly lower than the initial value, suggesting the presence of σ convergence at both the national level and across the four economic regions. Evidence supports both absolute and conditional β convergence in the CMS. Furthermore, a significant spatial correlation exists within the CMS, suggesting that the CMS level in one city not only affects its market but also influences neighboring markets. The findings of this study may contribute to the advancement of market integration.