The elasticity of substitution as an engine of growth

This paper characterizes the elasticity of factor substitution in one-sector convex growth models with a general production function. It shows that an elasticity of substitution that is asymptotically greater than one is a sufficient (but not a necessary) condition for the existence of a lower bound on the marginal product of capital, which in turn can lead to unbounded endogenous growth. Hence, an elasticity of substitution that becomes eventually greater than one can counteract the role of diminishing returns to capital. This renders factor substitution a powerful engine of growth.