Education for All? Measuring inequality of educational outcomes among 15-year-olds across 39 industrialized nations

Abstract

Measuring inequality of learning outcomes in a way that provides meaningful benchmarks for national policy while retaining a focus on those students who are ‘hard to reach’ and ‘hard to teach’ is a challenging but vital task in the light of the global post-2015 education agenda. Drawing on PISA 2012 data and its earlier rounds, this paper explores alternative approaches to measuring educational inequality at the ‘bottom-end’ of educational distribution within the cross-national context. Its main aim is to understand how far behind children are allowed to fall in their academic achievement compared to what is considered a standard performance in their country. Under the framework of relative (measured as achievement gap between the median and 10th percentile) and absolute (measured by the percentage of students achieving at a given benchmark) educational disadvantage it examines cross-country rankings as well as national trajectories with reference to overall academic progress.We find that on average across OECD countries around 11% of 15- year-olds lacked skills in solving basic reading, mathematical, as well as science, tasks in 2012, but variation across countries was large. The average achievement gap in mathematics across OECD countries between low-achieving and ‘average’ students stood at around 122 score points; in reading, at 131 score points; and in science, at 124 score points. This paper argues that understanding how the reduction in bottom-end inequality is achieved matters no less than the outcome itself, as it often reflects the level of support provided to low-achieving students. As our analysis shows, narrowing the achievement gap might be due to falling academic standards and have no direct benefit to the ‘bottom group’.