The puzzle of energy efficiency in Turkey: combining a multiple criteria decision making and the time series analysis

ABSTRACT Enhancing energy efficiency is important for sustainable economic development and environmental-related issues such as carbon emissions. Therefore, measuring energy efficiency is crucial for countries to achieve economic and environmental objectives. In this study, we utilize the TOPSIS method with the intent of monitoring the energy efficiency of Turkey from the 1980 to 2018 period. Several variables such as renewable and nonrenewable energy consumption, GDP, labor force, and capital stock are employed in calculating energy efficiency scores. Thereafter, we analyze the long-term, symmetric and asymmetric effects of some contextual variables such as capital stock-labor force ratio, renewable energy consumption-total energy consumption ratio, and carbon emission-total energy consumption ratio on energy efficiency via ARDL and nonlinear ARDL models. Results from the linear model indicate that an increase in the renewable energy consumption-total energy consumption ratio and capital stock-labor force ratio increase the energy efficiency. In contrast, an increase in the carbon emission-total energy consumption ratio decreases it. The nonlinear ARDL model, on the other hand, signals asymmetric effects in the long-run but not in the short-run.