Elasticity of substitution between clean and dirty energy inputs : a macroeconomic perspective

Recently Acemolgu, Aghion, Bursztyn and Hemous (AER 2012) formulated a model in which a high macroeconomic elasticity of substitution between clean and dirty production represents a crucial condition for green growth. Until now it has never been systematically estimated. Using a novel panel of cross-country sectoral data, we formulate specifications of nested CES production functions that allow to estimate a special case of this parameter: the elasticity of substitution between clean and dirty energy inputs. Contrary to what is expected based on the earlier interfuel substitution literature, we find evidence that this elasticity exceeds one.