An estimation of US industry-level capital–labor substitution elasticities: support for Cobb–Douglas

Abstract

A key parameter that determines the distributional impacts of a policy shift in general equilibrium models is the elasticity of substitution between capital and labor. Despite the importance of this parameter in applied modeling, its identification continues to pose a challenge. Given the structure of most growth models, we posit that the true relationship between capital and labor is likely to be close to Cobb–Douglas. Using a rich new data set from the Bureau of Economic Analysis (BEA), we estimate substitution elasticities for 28 industries that cover the entire economy, and provide an indication of the long- and short-run ranges of those estimates. We fail to reject the Cobb–Douglas specification in 20 of the 28 industries. These findings lend support to the Cobb–Douglas specification as a transparent starting point in simulation analysis.