Public data openness and urban carbon emission efficiency: empirical evidence from 282 cities in China

In the era of the digital economy, data resources have become increasingly important for sustaining economic growth and reducing carbon emissions, but the mechanisms through which they affect carbon emission efficiency (CEE) still require in-depth exploration. This study treats the launch of public data openness (PDO) platforms in Chinese cities as a quasi-natural experiment and conducts an empirical analysis using panel data from 282 cities over the period 2006–2021 to examine the impact of PDO on CEE, with a particular focus on its potential channels. The results indicate that PDO contributes to improvements in urban CEE. Alleviating resource misallocation, promoting cross-regional resource flows, and expanding the scale and improving the quality of green technological innovation are potential channels through which PDO affects CEE. In addition, green finance strengthens the positive impact of PDO on CEE. Heterogeneity analysis shows that the benefits of PDO are concentrated in cities with stronger socioeconomic and digital foundations. Further analysis suggests that PDO may widen intercity disparities in CEE, potentially contributing to uneven low-carbon development across cities. These findings provide new empirical evidence on the environmental value of public data governance and highlight the importance of considering both efficiency gains and regional equity when promoting data-driven low-carbon transitions.