Direction of trade and wage inequality

Contrary to the predictions of the 2x2x2 Heckscher-Ohlin model, empirical evidence shows that the skill premium increased in some developing countries and decreased in others after trade liberalization. Khalifa (2014) attempts to reconcile the empirical evidence with the theoretical predictions by introducing a theoretical set-up that includes the additional aspect of South-South trade. The model shows that South-South trade openness can cause the skill premium to increase in the Southern country that is relatively more skill abundant, and to decrease in the Southern country that is relatively less skill abundant. This article introduces an empirical analysis to test the theoretical predictions of Khalifa (2014) using threshold estimation techniques introduced by Hansen (1999). The results suggest the presence of a statistically significant skill abundance threshold, below which the estimate of the coefficient of the relationship between South-South trade openness and wage inequality is negative, and above which the point estimate is positive.