DEA environmental assessment in a time horizon: Malmquist index on fuel mix, electricity and CO2 of industrial nations

Climate change and global warming become a major policy issue in the world. Economic activities produce not only desirable outputs (e.g., electricity) but also undesirable outputs (e.g., CO2 emission). The important policy issue is how each nation can balance between economic development and environmental protection to attain a sustainable society. In attaining the sustainable society, environmental assessment is increasingly important because it can serve as an initial step toward the green growth of each nation. For the purpose, this study proposes a new use of DEA (Data Environment Analysis) for environmental assessment in a time horizon. The proposed use of DEA incorporates Malmquist index to examine the degree of a frontier shift among multiple periods. The frontier shift indicates a technology progress and/or managerial innovation during an observed period. The index is conceptually separated into six subcomponents, which are further divided into twelve different subcomponents (six subcomponents×two disposability concepts) under the natural and managerial disposability. In the index measurement, it is necessary for us to consider a frontier crossover among different periods because technology innovation usually has a time lag until it really appears. As an empirical application, this study utilizes the proposed approach to identify the relationship among fuel mix, electricity and CO2 of ten industrial nations. This study finds three important empirical findings. First, there is a time lag in technology innovation on electricity generation and CO2 emission reduction. Consequently, it is necessary to consider the existence of a frontier crossover in assessing the electric power industry. Second, nuclear generation, as found in France, as well as hydro and renewable energy, as found in Netherlands, are important for the development of a sustainable society although the former is associated with a very high level of risk and the latter has a limited generation capacity. Finally, the electric power industry has been making a corporate effort to reduce the amount of CO2 emission by utilizing nuclear and renewable energy.