A comment on the calculation of the total-factor energy efficiency (TFEE) index

This study provides a no-output growth model to conveniently calculate the total-factor energy efficiency (TFEE) index originally proposed by Hu and Wang (2006). The TFEE index serves as a very well-known and popular means of estimating overall energy efficiency. While many previous studies have used the indicator of energy inefficiency, including the indicator of energy intensity (i.e., Energy input/Gross Domestic Product (GDP)) to measure energy efficiency, Hu and Kao (2007) point out that the indicator of energy intensity is not only a partial-factor energy efficiency indicator, but that this partial-factor ratio is also quite inappropriate for analyzing the impact of changing energy use over time. The TFEE index overcomes the disadvantage of the indicator of energy intensity as mentioned above, but five steps are needed to calculate the TFEE score. In this study, we provide a no-output growth model to conveniently calculate the TFEE score. Furthermore, we extend this no-output growth model to an output growth model. This study concludes that the output growth model not only makes it easier to calculate the TFEE index than the model proposed by Hu and Wang (2006) and Hu and Kao (2007), but that it can also obtain better TFEE scores.