“…The nonparametric method refers to data envelopment analysis (DEA), which solves the problem of multi-input and multi-output by constructing the traditional DEA model (Andriamasy et al, 2014;Sun, 2020). Many scholars combine the DEA model with the Malmquist index to analyze the changing trends in technological innovation efficiency from the static and dynamic perspectives, respectively (Luo et al, 2019;Wang et al, 2019a;Liu et al, 2019;Sue & Ma, 2018). They regard the innovation process as a whole and directly measure overall efficiency without considering the internal structure rate (Tseng, 2009).…”