GTREM-1 (Eq. 1 with energy services) is the paper's headline specification in the main results Table 4; the abstract centers on the GTREM model || 'This paper estimates the level of transient and persistent efficiency... using the newly developed generalized true random effects model (GTREM).' (p.1) and 'GTREM-1 presents estimation results for the electricity input demand frontier function defined in Eq. (1)' (p.8)
Blasch, J., Boogen, N., Filippini, M., & Kumar, N. (2017): "Explaining electricity demand and the role of energy and investment literacy on end-use efficiency of Swiss households." Energy Economics, 68, 89–102.