Data on educational attainment come from Barro and Lee database (see additional resources), which classifies individuals into seven categories: no schooling, incomplete primary, complete primary, incomplete secondary, complete secondary, incomplete tertiary and complete tertiary. At a first stage, educational attainment rates are calculated for the four general categories using census data. Thereafter, these proportions are broken down into complete and incomplete categories using data on completion rates. We only use data for the four broad educational levels, without considering the decomposition of schooling rates into complete and incomplete, except for tertiary education.
Data on the official duration of primary and secondary education are drawn from UNESCO’s Statistical Yearbook (see additional resources), which includes series from 1970 onwards. We take into account changes in the educational system over time, assuming that those changes apply to the whole population. In line with previous studies, we assume that the duration of tertiary education is equal to 4 years in all countries over the whole period. The choice of 4 years of schooling is due to the high heterogeneity in the duration of tertiary education programs. On average, duration of completed short-cycle tertiary education (ISCED 5) was 3.7 between 2000 and 2010.