Thus, we do not examine these countries. Thus, 26-35 year-olds surveyed in 1994, 35-44 year-olds surveyed in 2003 and 44-53 year-olds surveyed in 2012 are all representative samples of the 1959-68 birth cohort. Our analysis focuses on literacy, which is measured in a comparable way in the three surveys.4 For the countries that participated in IALS, ALL and PIAAC we study birth cohorts that appeared in each of the three surveys. This investigation yields several noteworthy results.