Research on the economic development level differences among economies under the RCEP framework

Cross-border economic cooperation plays a vital role in helping China overcome challenges posed by national borders and address regional economic imbalances. Given the significant heterogeneity of borders and the localized spatial constraints of border effects, this study examines the spatial patterns of economic changes among economies in the Regional Comprehensive Economic Partnership (RCEP). Using the Theil index, the study compares economic development disparities across RCEP member countries while applying α-convergence and β-spatial convergence models to empirically explore economic development trends. The results reveal that the coefficient of variation in per capita GDP initially decreases and then increases, reaching its lowest point in 2019. This indicates a narrowing gap in per capita GDP, reflecting α-convergence and a more balanced distribution of economic development. Furthermore, absolute β-convergence is observed across 14 RCEP economies (excluding Myanmar), although spatial spillover effects are only significant at the aggregate level, with no spillover detected within subgroups. In conditional β-convergence, significant spatial effects are found in the overall and economically developed groups, while the economically underdeveloped group does not show such effects and is better explained by an ordinary panel model. Additionally, the study identifies that factors such as population growth rate, government public expenditure, fixed asset investment rate, and openness to trade have significant negative impacts on per capita GDP under the RCEP framework. These findings provide valuable insights into the dynamics of regional economic convergence within the RCEP and underscore both opportunities and challenges in achieving more balanced economic development.