*Article* **Estimating Relative Efficiency of Electricity Consumption in 42 Countries during the Period of 2008–2017**

### **Chia-Nan Wang 1,2, Quoc-Chien Luu 1,\* and Thi-Kim-Lien Nguyen 1**


Received: 26 September 2018; Accepted: 31 October 2018; Published: 5 November 2018

**Abstract:** Augmentation of electrical equipment is pushing for an increase in energy supply sources all over the world, as electricity consumption (EC) typically rises with growing populations. The value of EC reveals economic development and degree of emissions. Therefore, this research uses the undesirable outputs model in data envelopment analysis (DEA) for estimating relative efficiency of electricity consumption in 42 countries from 2008 to 2017. According to the principle of an undesirable outputs model and studied objectives, variables are selected that included population and EC as inputs, gross domestic product (GDP) as desirable output, and carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) as undesirable outputs. The empirical results indicate that 420 terms of 42 countries during the period of 2008–2017 have 102 efficient and 310 inefficient terms. Moreover, the interplay level between input and output factors every year is presented via scores. The study suggests the effect of EC to human life and propounds the emission status to look for directions to overcome inefficient terms.

**Keywords:** electricity consumption (EC); undesirable outputs model; data envelopment analysis (DEA); efficient; inefficient
