Association for Public Policy Analysis & Management

Measuring inequality of learning outcomes in a way that provides meaningful benchmark 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 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 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 10^th 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, which is equivalent to almost three years of schooling. The analysis has demonstrated that there is no trade-off between low levels of relative disadvantage and high absolute standards of educational achievement.  Estonia, Ireland, Latvia and Poland, for example, are countries that rank high on both measures. Meanwhile, a child in school in Bulgaria, Israel, the Slovak Republic and Sweden has a higher chance of falling a long way behind the average, and a lower chance of being educated to a minimum educational standard than a child on average in one of the OECD counties.

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 showed, narrowing the achievement gap might come with no direct benefit to the ‘bottom group’ but due to falling academic standards (examples of Belgium in maths or New Zealand in reading).  Meanwhile, the most worrying, although not a very common, scenario of increasing achievement gap alongside falling median test scores is observed in Finland and Sweden. From the perspective of this paper the choice of addressing inequality of educational outcomes is that of redirecting limited resources to support the students with the greatest educational needs.  Broadening the definition of special educational needs, cross-curriculum support and prevention of school segregation are needed, particularly in countries with already high academic standards.