Those data and approach could not be used in the present analysis, however, due to the lack of yearly data on inequality for a large enough number of OECD economies. Figure 4 displays a simple cross-country correlation between the share of population enrolled in upper secondary (left panel) and tertiary education (right panel) and the Gini coefficients of disposable income inequality. The ratio of Upper secondary enrolled is computed relative to the population aged 15-19 (20-24 for the ratio of tertiary enrolled).