A note on intermediate imports and the BPCG model in Mexico

Numerous applications of the balance-of-payments-constrained growth (BPCG) model have concluded that Mexico’s equilibrium GDP growth rate fell after trade liberalization, because of a sharp rise in the income-elasticity of imports. Following the bounds testing approach of Pesaran et al. (2001), the present note estimates equations for intermediate and other types of imports in Mexico from 1960 to 2006. It shows that intermediate imports are significantly affected by manufactured exports, and that once the effect is controlled for, there is no significant rise in their income-elasticity—in contrast to what is observed for other types of imports. Since manufactured exports are highly intensive in imports, what the typical BPCG regression detects as an increase in the elasticity of intermediate imports may reflect a compositional effect, namely, the re-composition of GDP towards exports. Some implications for the BPCG model are briefly discussed in the conclusions.