RESEARCH ON EVALUATION OF INNOVATION ECO-EFFICIENCY OF CITY CLUSTERS IN THE MIDDLE REACHES OF THE YANGTZE RIVER BASED ON THREE-STAGE DEA METHOD

Urban agglomerations play an increasingly important role in promoting the development of regional economy, hut the ecological and environmental problems are more prominent. In this paper, first, based on the spatial gravity model, the economic connection strength of the middle reaches of the Yangtze River is estimated. Secondly, an evaluation index system is constructed from the perspective of ecology, The three-stage DEA method is used to evaluate the efficiency of the five major urban agglomeration innovation ecosystems, and to identify the restricting urban agglomeration and the key factor of innovation ecosystem. The results show as follows. (1) three-stage DEA can effectively eliminate the influence of random errors and external environmental factors on regional innovation efficiency, (2) Among the five biggest city clusters. the Yangtze River Delta city clusters has the highest average comprehensive efficiency, followed by the Pearl River Delta Region. (3) In the third stage. except the Beijing-Tianjin-Hebei city clusters, the comprehensive efficiency of the other four city clusters decreased compared with the first stage. Among them, the change trend of the comprehensive efficiency value was consistent with the pure technical efficiency value, which indicated that the change of the comprehensive efficiency was mainly dependent on the technical change.