The impact of the digital economy on energy productivity: An empirical analysis based on 30 provinces in China

The digital economy boosts productivity through the deep integration of digital technologies with the real economy, offering a significant opportunity for enhancing energy productivity. Using panel data from 30 provinces across mainland China between 2011 and 2021, this study investigates the complex interactions between energy structure transformation and energy productivity improvements. A restricted cost function incorporating energy structure is employed to estimate energy productivity, and multidimensional indicators of digital economy development are constructed. The effects of digital economy on energy productivity are empirically tested using various methodologies, such as Driscoll-Kraay standard errors, system GMM model, the dynamic threshold model, the causal mediation model, and the dynamic spatial durbin model. The findings indicate that: (i) On average, China's energy productivity is significantly enhanced by digital economy, with each unit increase in the digital economy raising energy productivity by about 1.579 units. However, this positive effect shows a threshold effect: when R&D investment is below a certain level, the influence of the digital economy on energy productivity is negative; once the threshold is surpassed, the effect becomes significantly stronger. (ii) The analysis of regional heterogeneity reveals that digital economy has a significant positive impact on energy productivity in the eastern and central regions of China, but its effect on the western region is negligible. (iii) Mechanism analysis suggests that the digital economy improves energy productivity mainly by upgrading industrial structures and enhancing the marketization of factor resources. (iv) Spatial correlation analysis shows that while digital economy in core regions can temporarily boost energy productivity in neighboring regions, the spillover effect is unsustainable. In the long run, the digital economy in core regions tends to suppress energy productivity improvements in surrounding areas. Based on these findings, it is recommended to accelerate energy productivity growth by broadening R&D investment channels, promoting coordinated regional digital economy development, and refining regional energy policies.