Of the additional tax revenue collected since 2002 more than half came from direct taxes, a third from TVA, and the rest from other taxes. Overall, while tax reform still has a long way to go, these changes rendered the tax system a bit more equitable. In addition, countries benefiting from gains in terms of trade appropriated part of these windfall gains in the form of non-tax revenue (half a point of GDP on average, and by 3 to 4 points in the key commodity exporters (CEPAL, 2007). Detailed research shows that returns to education rose following wage liberalization, technological modernization and growing informalization (Mitra and Yemtsov, 2006) .