Exploring the impact of population urbanization on the green economy development: A case study of 30 provincial-level administrative regions in China

The green economy development (GED) has emerged as a paramount objective for urban progress in the 21st century, emphasizing the harmonious advancement across economic, social, and environmental domains. Yet, the impact of population urbanization, a pivotal driver of urban evolution, on GED remains ambiguous. Addressing this knowledge gap necessitates investigations at specific stages of rapid population urbanization in a certain country. In order to explore the relationship between them, this study focuses on China, a distinctive economic entity, utilizing the DEA-SBM model with unexpected outputs to assess its GED efficiency (GE). Additionally, employing the Tobit model, the study scrutinizes the impact of population urbanization on GE in China from 2000 to 2020. Mechanism analyses are further conducted to explore the key roles of environmental policies, population density, and R&D in fostering GE. Findings reveal: (1) a U-shaped relationship between population urbanization and GE; (2) significant enhancement of GE through green credit policy, alongside positive moderating the impact of environmental protection on GE; conversely, environmental assessment policy notably reduce GE, while positively moderating the impact of industrial structure rationalization on GE; (3) a U-shaped relationship between population urbanization and GE under low population density, with population urbanization significantly diminishing GE as population density reaches a critical level; (4) higher amount of R&D personnel corresponding to increased GE at equivalent population urbanization levels. Finally, several management strategies derived from these findings are offered, aiming to assist other developing nations in effectively improving their urban GE.