Can transparency governance promote interregional coordinated carbon emission reduction? A new perspective from China provincial transparency index

As the Chinese government places increasing emphasis on the establishment of mechanisms for carbon emission reduction and inter-provincial collaboration, transparency governance offers a novel solution to the traditional challenges of territorial governance in this context. This paper innovatively constructs a Provincial Transparency Index (PTI) for China and examines the effect of transparency on provincial carbon emission reduction using panel data models and spatial Durbin models. Furthermore, a hierarchical regression analysis is conducted to test the mechanisms. The results reveal that the PTI has a significant impact coefficient of 0.481 on carbon emissions, while the quadratic coefficient is −0.693, indicating that PTI has an inverted "U" - shaped effect on local carbon emissions, with significant spatial spillover effects that diminish marginally. Transparency governance primarily promotes inter-provincial coordinated carbon reduction by reducing collaboration costs through marketization and increasing breach costs through institutional guarantees. Therefore, China should accelerate the establishment and improvement of transparency governance mechanisms for collaborative carbon reduction among provinces, and enhance the disclosure and supervision of carbon reduction information at the provincial level. • Transparency exhibits an inverted "U"-shaped effect on local carbon emissions in China. • Transparency enhances regional collaboration in carbon reduction across China. • Transparency fosters regional cooperation by lowering collaboration costs. • Strengthening market mechanisms and encouraging regional voluntary efforts are key to China's carbon reduction strategy.