and at the secondary level, international student achievement tests point to desperately low levels of learning in many low- and middle-income countries. in the most recent Programme for international Student assessment (PiSa), two thirds or more of secondary school students in argentina, Brazil, Colombia, indonesia, Jordan, Peru, Qatar and Tunisia were performing below level 2, a marker of baseline proficiency in math. less than 1 per cent were performing at the top two levels. in comparison, an average of 23 per cent of students in the high-income organisation for economic Co-operation and development (oeCd) countries were low-achieving, and 13 per cent 153 performed at the top level. evidence from latin america underscores the interaction between inequity and low levels of learning achievement. research on the 2012 PiSa scores by the inter-american development Bank found that the average gap between the poorest and richest students of the same age in the region was equivalent to two years of schooling.154 Such failures in learning have repercussions for children’s futures and for national prosperity. Many education systems fail to teach children the skills they need to become productively employed adults and contribute to national social development and economic growth. The costs of misalignment between skills and jobs are visible in many parts of the world. according to the international labour organization, the share of aroUnd one in fiVe YoUnG undereducated young workers in low-income economies is triple that of the PeoPle in oeCd CoUnTrieS share in upper-middle-income economies. in sub-Saharan africa, three in five young workers do not have the level of education needed for their jobs.155 do noT CoMPleTe SeCondarY employer surveys in the Middle east and north africa indicate a pervasive edUCaTion. disconnect between the skills learned in school and those demanded by modern business.156 That mismatch is one of the reasons for the persistently high levels of unemployment among educated youth in the region, and it is an issue facing young people worldwide. as the high-level Commission for Quality education for all in latin america has summarized the problem: “Without significant improvements in learning levels, the rising levels of schooling will hardly turn into the improvements in 157 quality of life to which latin american citizens aspire.” high-income countries also face learning challenges. The growth in the number of children with access to education in oeCd countries has resulted in 80 per cent of young people achieving upper secondary qualifications and a 158 quarter gaining tertiary education. however, around one in five young people in oeCd countries do not complete secondary education and have to make the transition to adulthood facing the prospect of lower wages, less secure employment and marginalization.159 This education gap is an increasingly powerful determinant of wider inequalities in wealth and opportunity, 160 hampering the development of more inclusive societies. for governments, addressing the problems at the source – within education systems – is the most cost-effective way to make sure that children and young people develop the skills and competencies they need. efforts to narrow the learning gaps are under way. in Tunisia, for example, the government has embarked on a major reform process to improve learning outcomes for children in school and on a comprehensive programme for out-of-school 161 children. The STaTe of The World’S Children 2016 51