Río Iglesias, Fernando delRebelo, Francisco2026-01-122026-01-122026del Río, F., & Rebelo, F. (2025). Normalizing VES Production Functions: Extending the Supply-Side System Approach. Economics Letters, 112794. https://doi.org/10.1016/J.ECONLET.2025.1127940165-1765https://hdl.handle.net/10347/45008This paper extends the Klump et al. (2007) normalization procedure to Variable Elasticity of Substitution (VES) production functions. Normalization addresses identification issues in VES model estimation, allowing joint estimation of substitution elasticities and factor-augmenting technical change, while offering a tractable extension of the normalized supply-side system that bridges the gap between CES and more flexible VES specifications.eng© 2025 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).Attribution 4.0 Internationalhttp://creativecommons.org/licenses/by/4.0/Variable elasticity of substitution (VES)NormalizationFactor-Augmenting Technical ChangeIdentificationCapital-labour elasticity of substitutionNormalized supply-side systemjournal article10.1016/J.ECONLET.2025.1127941873-7374open access