Many of the surveys contain a direct question eliciting years of schooling completed. For the surveys where no such variable is available, UNESCO sources containing country- and yearspecific mappings on the duration of educational programs are relied upon to construct a measure of years of education based on the answers to the categorical question.<sup>13</sup> The length of the various ISCED categories varies across countries, and changes over time within countries. Individuals are assigned to an educational regime based on their birth year and the school entry age. When reforms occur at an education level, it is assumed they apply to individuals who have not yet entered that education level. For example, it is assumed that an extension of lower secondary from 3 to 4 years does not affect children who are already enrolled in lower secondary.<sup>14</sup> Years of schooling do not account for differences in the quality of education. A year of schooling in, say, Singapore may be of very different quality than a year of schooling in Malawi. Due to a lack of global data on educational quality, especially for the cohorts considered in this paper, years of schooling is relied upon here. To the extent that quality of schooling is relatively stable over time (i.e. varies primarily between countries and comparatively less within country and over time), comparisons of individual educational attainment relative to that of their parents would be approximately independent of school quality. In that case, the implication of not observing educational quality for the estimation of intergenerational mobility is conceivably modest.

# **4. Intergenerational mobility around the world**

## **4.1. Absolute mobility is highest in the developed world**

Absolute mobility in education is found to vary considerably across the 153 economies (for those born in the 1980s), with a clear geographic pattern (Figure 1). Sub-Saharan Africa stands out as the region with some of the lowest rates of absolute mobility. In some of the poorest or most fragile countries in the region, the share of respondents that have more education than their parents is less than 20 percent, compared to over 80 percent in parts of East Asia. Of the 15

> 13 Two sources of information are used. The first source (http://uis.unesco.org/en/isced-mappings) is not available for all countries and for the most part only conveys the duration of ISCED categories in 1997 and 2011. This source is supplemented with information from UNESCO’s online database <u>(http://data.uis.unesco.org/), which outlines the</u> length of durations of ISCED categories by year from 1970.

> 14 The UNESCO information is not available before 1970, so for individuals who went to school before 1970 the durations from 1970 are applied. When information is missing in the UNESCO sources, additional country-specific information is used or the following rule for converting ISCED categories to completed years of schooling is applied: (i) ISCED 1: 6 years, (ii) ISCED 2: 9 years, (iii) ISCED 3: 12 years, (iv) ISCED 4: 13 years, (v) ISCED 5: 15 years, (vi) ISCED 6: 16 years, (vii) ISCED 7: 18 years, and (viii) ISCED 8: 21 years. In a handful of countries, a years of schooling variable is present but a categorical variable is not. In these cases, the reverse conversion using the country- and year-specific mappings is used.

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