Can Industrial Agglomeration Policies Promote Environmental Development? Evidence from the Guangdong–Hong Kong–Macao Greater Bay Area in China

As the issues of climate change and environmental sustainability continue to intensify, reducing carbon emissions (CO 2 ) has become an urgent global issue. Based on this background, industrial agglomeration is an economic organisation form that promotes efficient resource allocation and exhibits significant environmentally friendly characteristics. Through spatial agglomeration and synergy between firms, industrial agglomeration can not only promote green technology innovation but also effectively reduce energy consumption and pollution emissions, providing a new path for achieving coordinated development of the environment and the economy. However, the impact of industrial agglomeration policies on environmental development is still worth exploring. This study uses a difference-in-differences (DID) approach to examine the effects of industrial agglomeration policies on CO 2 and carbon emission intensity (CO 2 I) and verify the contribution of the net effect of such policies on the environment in the Guangdong–Hong Kong–Macao Greater Bay Area (GBA) in China. The results show that the implementation of these policies contributes to reducing CO 2 and improving environmental performance in the GBA, thereby contributing to a more sustainable and environmentally friendly future.