Eco-efficiency evaluation and productivity change of Yangtze River Economic Belt in China: a meta-frontier Malmquist-Luenberger index perspective

Using city-level panel data for 2008-2017, this paper uses the super-efficiency slack-based measure (SBM) model to measure the eco-efficiency in the Yangtze River Economic Belt (YREB). Based on the group-frontier Malmquist-Luenberger (GML) productivity index and meta-frontier Malmquist-Luenberger (MML) productivity index, the driving forces of the total factor ecological productivity are analyzed. The results show the following: (1) The overall eco-efficiency in the YREB was 0.599 and remained stable during the study period, showing only a fluctuating and slightly upward trend. (2) The annual average GML index was 1.091 in the YREB, and the main reason for the improvement in the GML index was technological progress. (3) The average annual growth of MML index in the YREB was 8.2%, and the change of the best practice gap ratio was the main reason for the MML index increase. (4) The technical gap ratio indicates that the gap between group-frontier and meta-frontier is narrowing slightly, which is conducive to the coordinated development of the ecology in the YREB.