The Antonelli Versus Hicks Elasticity of Complementarity and Inverse Input Demand Systems

A true measure of input substitution associated with exogenous changes in input quantities requires that the output level be held constant. To this effect, this study presents the Antonelli elasticity of complementarity characterised by the distance function. The more common Hicks elasticity of complementarity assumes that marginal cost is constant and hence does not capture pure substitution effects. The two elasticities of complementarity are related to inverse demand systems and are shown to be equivalent under constant returns to scale. A framework for estimating the Antonelli elasticity from the uncompensated demand system is presented. Estimation results reveal substantial bias of input substitutability with the use of Hicks' measure. Copyright 2000 by Blackwell Publishers Ltd/University of Adelaide and Flinders University of South Australia