Research and development efficiency, state-owned enterprises, and carbon intensity in China

• Considered the effects of R & D efficiency and the proportion of SOEs on carbon intensity. • Through technological progress, R & D efficiency and the proportion of SOEs impact carbon intensity. • The proportion of SOEs can moderate the relationship between R & D efficiency and carbon intensity. • R & D efficiency and the proportion of SOEs influence not only the carbon intensity of a province but also that of neighboring provinces. This study investigates the effects and transmission mechanisms of research and development (R & D) efficiency and the proportion of state-owned enterprises (SOEs) on carbon intensity using data from 30 Chinese provinces. The findings show that improving R & D efficiency can lower carbon intensity by promoting technological progress. However, more SOEs can increase carbon intensity by inhibiting technological progress. Thus, a higher proportion of SOEs can reduce the positive impact of R & D efficiency on decreasing carbon intensity. Additionally, the proportion of SOEs has a moderating effect that extends beyond provincial boundaries, resulting in spatial spillover due to strong interconnections between provinces. Heterogeneity analysis indicates that this moderating effect is particularly pronounced in the central and western regions, as well as in the electricity sector. This variation is due to differences in economic development levels and government priorities. Given the characteristics of China’s carbon intensity, policymakers should shift from a one size fits all carbon reduction policy to prioritizing enhancing R & D efficiency, boosting the innovation capabilities of SOEs, and considering spatial linkages and regional disparities.