Unintended consequences: China's pairing assistance policy and carbon emissions in administrative border areas -evidence from China.

The investigation of the unintended impact of pairing assistance policies on carbon emissions in administrative boundary regions is critical for achieving the "dual carbon" goals. This paper utilizes a sample of cities from the Pearl River Delta and the eastern and western regions of Guangdong, China, spanning from 2006 to 2020. A quasi-natural experiment based on the co-construction of industrial parks is employed to examine its impact on carbon emissions in boundary regions. The study finds that while pairing assistance policies are intended to suppress carbon emissions in assisted boundary regions, they inadvertently exacerbate carbon emissions in those regions. This effect is realized by breaking market segmentation and forcing high-carbon enterprises to exit. The increase in carbon emissions in assisted boundary regions is driven by the industrial transfer mechanism, with regions having lower labor costs more likely to attract polluting enterprises. Further analysis reveals a "distance attenuation effect" of the policy on carbon emissions in the assisted regions. Directive assistance relationships from upper-level governments, moderate environmental regulation, and high levels of economic development can amplify the carbon reduction effect of the policy in boundary regions. This study contributes to a deeper understanding of the causes of persistently high carbon emissions in boundary regions and provides theoretical insights for developing countries to better coordinate interregional assistance policies and strengthen environmental governance.