“…These differences in inputs also apply to outputs in research efficiency measurement: number of publications (Amara et al, 2020;Canal et al, 2015;Cherchye and Abeele, 2005;Jiang et al, 2020;Jimenez-Saez et al, 2011;Ma et al, 2021;Munoz, 2016;Su et al, 2020;Wang and Wang, 2021), research grants (Ma et al, 2021;Munoz, 2016), R&D contracts (Jimenez-Saez et al, 2011), technology transfer income (Wang and Wang, 2021), number of science awards (Jiang et al, 2020), number of research awards (Liao et al, 2016), number of citations (Amara et al, 2020;Rhaiem and Amara, 2020), number of citations per article (Li et al, 2023;Su et al, 2020), impact factor of articles (Liao et al, 2016) and number of highly cited papers (Li et al, 2023). As can be seen, there is no standard output criterion in the studies.…”