Achievements in mathematics, science, and literacy skills are related to educational attainment and success on the labor market, resulting, for instance, in more desirable jobs and higher wages later in life. Yet, we know that the education of one’s parents as well as whether one’s parents or oneself is born in the country in which one attends school matters a lot for one’s educational achievement. In this ISOTIS report, we seek to answer: how do these differences in achievement by socioeconomic and migration background vary between countries over time and across the life course?

Therefore, we combined information from more than 5.6 million individuals from 103 regions. The findings indicated:

• There are substantial differences in test-scores between children from different socioeconomic backgrounds, with children from higher educated parents performing better. Smaller differences are found between children with and without a migrant background in Europe.
• Socioeconomic inequalities are particularly large in Central-Eastern European countries, while inequalities by migration background are particularly large in North-Western Continental European countries.
• Socioeconomic inequalities seem to be stable over time, but may have slightly increased between 1995 and 2015. Inequalities by migration background fluctuate more, and were observed to increase again, especially in later stages of the school career, in recent years.
• Inequalities by socioeconomic and migration background seem to evolve similarly over the life course: being already large at grade 4 (approximately age 10), remaining stable or even declining while children follow primary and secondary education, and increasing again around age 21 when children leave secondary and tertiary education.

Thus, high quality environments and the promotion of equality in primary and secondary schools may reduce the inequality trends by socioeconomic and migration background, and work as equalizers. In addition, there are large differences between countries in how large the inequalities are. In our next ISOTIS report, we will address the question: Are some national policies more effective in tackling inequalities than others?