Evaluation and welfare effect of coordinated ecological development of the Beijing-Tianjin-Hebei region

Regional coordinated ecological development is a new form of regional coordinated development that aims to construct an ecological civilization in the "new normal" period. The coordinated ecological development of the Beijing-Tianjin-Hebei (BTH) region is especially significant because this region is leading the overall coordinated development and reform in China. Based on complex system theory, synergetics, and the ecological civilization and green development ideas of the "new normal" period, we constructed a regional ecological synergy measurement model that scientifically evaluates the dynamic evolution of the BTH ecological synergy level from 2006 to 2018. Using an econometric model, we also analyzed the welfare effect and the regional heterogeneity of ecological synergy in regional development. First, it was found that in general, the degree of ecological synergy in Bill increased yearly up to 2018 with a strong development trend. The speed of ecological synergy in the Tianjin-Hebei and Beijing-Hebei subsystems was accelerating during that period, but the development potential of the ecological synergy in Beijing-Tianjin was insufficient and slow-growing. Second, whereas Beijing had entered the stage of moderate coordinated ecological development, Tianjin and Hebei remained in the low level of coordinated development; moreover, the coordinated development was unstable. The uneven development of the internal subsystems in BTH restricted the development of the cooperative effect and the overall development of the region. Third, improving the degree of ecological synergy significantly benefited the social and economic welfare in BTH. Finally, the welfare effect of the degree of ecological synergy showed a significant regional heterogeneity, being significantly higher in Tianjin and Hebei than in Beijing. This result indicates that improving the ecological synergy can narrow the development gaps between Tianjin, Hebei, and Beijing. To further improve the level of regional ecological synergy, we should innovate the coordinated model of regional development, implement the collaborative ecological development model, generate new growth drivers for the green development of Bill based on a reasonable division of labor, difference positioning, and active integration, create a soft environment for an innovation ecosystem that promotes regional ecological synergy, and build a regional innovation ecosystem led by Beijing and Xiongan. Next, we should establish a balanced regional-interest mechanism with ecological environmental protection that supports regional green and high-quality development.