Curvature and the elasticity of substitution: Straightening it out

This paper demonstrates that, contrary to deeply rooted beliefs, there is no link between curvature and the elasticity of substitution. We show that there is no direct, nor inverse, relationship between the two concepts, if curvature of the isoquant is defined either in its strict mathematical sense or as the isoquant's second derivative. We finally suggest to view the elasticity of substitution as an efficiency parameter.