Armington Parameter Estimation for a Computable General Equilibrium Model: A Database Consistent Approach

Substitution elasticities in policy-oriented computable general equilibrium (CGE) models are key parameters for model results since they determine behaviour in these models. As Dawkins et al. (2001) observe, the current situation with regard to the elasticities available for use in these models is poor. We focus on an important type of elasticity that is widely used in CGE models with international trade: the so-called ‘Armington’ elasticities (Armington, 1969). These elasticities are well known for their critical role in determining model results. We present an alternative approach to quantifying Armington elasticities which is consistent across historical databases. The approach is used to derive elasticities from successive databases of a commonly-used global CGE model, the GTAP model.