Demand elasticities derived from consistent estimation of Heckman-type models

Abstract

As proved lately, the use of the Inverse Mill's Ratio as a correction factor in the second step of Heckman-type models leads to inconsistent estimates. One area where this type of model has been extensively used is the applied food demand analysis. As a consequence the derived demand elasticities are no longer valid. In this paper the appropriate expressions for demand elasticities are derived and are applied to 23 food items using family budget survey data.