Energy efficiency and capital-energy substitutability: Evidence from four OPEC countries

Rapid economic growth and development in several oil-exporting developing countries have led to increasing energy consumption and the accompanying greenhouse gas (GHG) emissions. Consequently, a good understanding of the nature and structure of energy use in developing economies is required for future energy and climate change policies. To this end, a modified translog cost function is employed in this paper to estimate energy efficiency for selected members of the Organization of the Petroleum Exporting Countries (OPEC) over the period 1972–2010. This also allows for the estimation of energy-capital substitutability, which arguably reflects the likely ease/disruption to long-term growth arising from policy measures aimed at reducing energy consumption and GHG emissions. The estimated results show that energy efficiency gains range from −14% to 13% for sampled countries. Furthermore, factor substitution elasticities suggest that energy and capital are substitutes in Algeria and Saudi Arabia, but are found to be complements in Iran and Venezuela. The insight generated by this study is that, over the last four decades, energy efficiency improvements in selected OPEC countries are modest, possibly reflecting a “subsidy effect” arising from artificially low energy prices. Thus, policy makers should take note that measures aimed at conserving energy need to internalize the environmental cost arising from energy consumption using pricing and fiscal instruments such as carbon taxes.