“…In terms of the influencing factors of ULGUE, previous research is usually focused on four aspects: economic factors (Hu and Qian, 2017), social factors (Nesru et al, 2021;Zhao et al, 2021;Zhao and Jiang, 2022), traffic location (Desalvo and Su, 2017), and policy factors (Macedo., 2008;Wang and Chi-Man, 2017). Besides, there have also been some studies concerning the internal relationship of industrialization (Ghosh and Chifos, 2017;Bird andVenables, 2020), urbanization (Hsing-Fu andKo-Wan, 2015;Marco et al, 2015), regional integration (Cancello et al, 2020) with ULGUE. In the above studies, the econometric model was the mostly used tool to analyze issues related to ULGUE, mainly including the parametric method represented by stochastic Frontier production function model (Dong et al, 2020;Liu S C et al, 2020;, the non-parametric method represented by Data Envelopment Analysis (DEA) model (Fang et al, 2013;Chen et al, 2021;Liu et al, 2021;Ruan et al, 2022), SBM model and its improved model (Lin and Ling, 2021;Tang et al, 2021;.…”