Heterogeneous Effects of Industrial Agglomeration on Carbon Emissions and the Moderating Role of the Digital Economy: Evidence from Different City Types in the Yangtze River Delta

This study proposes a novel analytical framework that integrates the digital economy, industrial agglomeration, and carbon emissions. It then applies this framework to examine the heterogeneous impacts of secondary and tertiary sector agglomeration on carbon emissions and the moderating role of the digital economy across different city types within the Yangtze River Delta (YRD). The results suggest that secondary sector agglomeration generally increases carbon emissions, while tertiary sector agglomeration reduces them, with variations across city types. In developing cities, secondary sector agglomeration raised carbon emissions between 2010 and 2017, tertiary sector agglomeration reduced carbon emissions until 2019. Super-hub cities exhibited an opposite trend during the 2012 to 2017 period. The digital economy and each of its dimensions positively affect carbon emissions from secondary sector agglomeration but negatively impact carbon emissions from tertiary sector agglomeration to varying degrees. The study thus proposes tailored policy recommendations to promote the synergy of digitalization and green development, as well as the advancement of low-carbon industries.