Flexibility in input substitution: A case study of South African agriculture

Differences in elasticities of substitution between agricultural inputs over time in South African agricultural production were measured. The translog functional specification was used for empirical estimation of factor share equations derived from cost data. This was done by using duality that exists between the production function and the cost function along the expansion path. South African agriculture exhibits less flexibility in dealing with input price variation, especially machinery, than US agriculture. The relative rigidity of the South African agricultural production process may at least partially be attributed to present competitive structures, and has important implications for development policy, especially with regard to the success obtained with policy measures favouring relative input subsidisation over the short term.