A growing consensus worldwide has indicated the need to protect the ecological environment and achieve sustainable development. Ensuring ecological protection and high-quality development of the Yellow River basin have become China's major national strategy. We reviewed extant literature, summarised government reports and guidance documents on the Yellow River basin, and proposed introducing a strong sustainable development theory into the study of total factor productivity (TFP). The spatial–temporal evolution and influencing factors of urban ecological TFP in the Yellow River basin are of great practical significance. We proposed a new ecological TFP indicator: the modified input-oriented Luenberger productivity indicator (MIL). Using panel data from 78 cities in the Yellow River basin during 2003–2019, we measured the urban ecological TFP. We adopted the geographic information system tool and kernel density estimation to analyse the temporal and spatial evolution of the indicator, as well as its spatial effects and influencing factors, using the global Moran's I index and dynamic spatial Durbin model (SDM). Our results show that, during the sample period, our indicator increased in cities in the region with an average annual growth rate of 0.627%, driven by technological progress. The average annual growth rate in urban areas showed a decreasing distribution of ‘downstream-midstream-upstream’. Fiscal decentralisation (FD), industrial structure (IND), financial development (FIN), urbanisation level (URB) and research and development (RD) investment improved growth rates in this and the adjacent regions through direct and indirect effects. However, environmental regulation (ER), opening level (OPEN) of cities and population density (POP) were obstacles to TFP growth.

Macroeconomic stability is the core concept of sustainable development. However, the coronavirus disease (COVID-19) pandemic has caused government debt problems worldwide. In this context, it is of practical significance to study the impact of government debt on economic growth and fluctuations. Based on panel data of 30 provinces in China from 2012 to 2019, we used the Mann–Kendall method and Kernel Density estimation to analyze the temporal and spatial evolution of China’s provincial government debt ratio and adopted a panel model and HP filtering method to study the impact of provincial government debt on economic growth and fluctuation. Our findings indicate that, during the sample period, China’s provincial government debt promoted economic growth and the regression coefficient (0.024) was significant. From different regional perspectives, the promotion effect of the central region (0.027) is higher than that of the eastern (0.020) and western regions (0.023). There is a nonlinear relationship between China’s provincial government debt and economic growth, showing an inverted “U-shaped” curve. Fluctuations in government debt aggravate economic volatility, with a coefficient of 0.009; tax burden fluctuation and population growth rate aggravate economic changes. In contrast, the optimization of the province’s industrial structure and the improvement of the opening level of provinces slow down economic fluctuations.

While the rapid development of two-way foreign direct investment (FDI) has boosted China’s economic growth, its impact on environmental quality is uncertain. Based on provincial panel data from China covering the period from 2002 to 2020, this paper proposes an environmental quality assessment index system for China from two aspects: environmentally cleaner production and environmental end treatment. The comprehensive environmental quality index (EQI), environmentally cleaner production index (EPI), and environmental end treatment index (ETI) were all measured, with the geographic information system tool and Dagum Gini coefficient used to analyse the indicators’ differences using a system-generalised method-of-moments (SYS-GMM) estimation to study the impact of two-way FDI on environmental quality in various regions across China. The results demonstrate that during the sample period, inward FDI positively impacted environmental quality and cleaner production but had a negative impact on environmental end treatment. Outward FDI significantly promoted EQI, EPI, and ETI, and the interaction between inward FDI and outward FDI positively impacted environmental quality and environmentally cleaner production, while it negatively impacted environmental end treatment. This indicates that under two-way FDI, China’s relationship with environmental quality has gradually evolved from ‘pollution first and then treatment’ to ‘green development of cleaner production’.