The objective of this paper is to estimate transformation and Armington substitution elasticities for South African trade. We use linear methods to estimate elasticities without growth factors. We then employ a non-linear system of equations to estimate Armington import elasticities and related...

The structure introduced by Armington (1969) has been used to analyze trade policy in partial and general equilibrium models. The Armington elasticities, the degree of substitution between domestic and import goods are known to be important, but are seldom estimated empirically. Therefore, we...

We propose a simple method to identify the effects of unilateral and non-discriminatory trade policies on bilateral trade within a theoretically-consistent empirical gravity model. Specifically, we argue that structural gravity estimations should be performed with data that include not only...