Thomas J. Alexander Fellow, Directorate for Education and Skills
|Distribution of efficiency scores by country |
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In the working paper, we propose an innovative use of PISA data for measuring the efficiency of schools in an international comparison; more specifically, we compare the efficiency scores of more than 8 600 schools in 30 countries using PISA 2012 data. The study deals with the following key research questions:
a) How relevant are the differences in the efficiency of schools across the selected 30 countries? Are these differences driven more by between-schools or between-countries variance?
b) Which factors are associated with schools’ efficiency scores? And, are these factors common across all countries?
c) Is there a trade-off between efficiency and equity at school level?
All three questions can have policy and managerial implications, and each of them also opens the door to potential benchmarking exercises that can prompt school principals to look at the most efficient schools in the world, investigating the drivers of their performances.
Using a non-parametric technique, called Data Envelopment Analysis (DEA), that measures efficiency scores from 0 to 1 (where 1 is maximum efficiency level observed in the sample), we find that efficiency scores vary widely both between and within countries. When considering all schools together – so allowing for the existence of an international common benchmark – we find that on average schools can raise their scores by 27%, ranging across countries from 15% for schools in Singapore to more than 33% for those in Slovenia. The Figure 1 highlights how dispersed efficiency scores are within countries; these efficiency scores of schools within countries encompass the entire range of the international distribution of efficiency, underlying the fact that country average efficiency scores mask substantial internal variation.
When we compare each school with those operating in the same country, the average improvement in output is estimated at 15%, ranging from 6%, on average, among schools in Ireland to 22% among those in Slovenia. This result suggests that it could be necessary to consider an international benchmark for efficiency analysis; indeed, the room for improvement is much larger when considering in the sample institutions from various contexts. International benchmarking exercises are really options for opening the mind to more ambitious performance goals – and at lower cost.
We also investigate if are there factors at the school and country levels that are associated with efficiency. These second-stage variables have been classified in three main groups: students’ characteristics, other than socio-economic status, general characteristics of the schools, and schools’ practices and processes. This last group of variables can help policy makers and school managers to act for improving institutions’ efficiency. The results reveal that the characteristics of the student intake in each school (i.e. the proportion of girls and immigrants, the diversity of socio-economic background, etc.) explain most of the variation in efficiency across schools; however, school-related factors (i.e. practices such as extracurricular activities, principals’ leadership style, etc.) also play a role in describing differences in efficiency across schools.
In the last part of the study, we discuss how we find no evidence of a trade-off between efficiency and equity; in other words, more efficient schools tend to be more inclusive. Efficiency scores are related to greater inclusion, as measured by the percentage of students in the school who score above proficiency Level 2, the baseline level of performance in PISA.
Limitations on methods and data sources imply that the estimated efficiency scores are only proxies for true efficiency. Most importantly, they do not provide precise measures of efficiency at the school level and any attempt to use these measures to rank schools would be ill conceived. Yet, these estimates provide a clear picture of the distribution of schools’ efficiency scores across and within countries.
We hope that this contribution can help to direct researchers’ attention towards this topic, to explore further the factors that affect efficiency in education.
The Efficiency of Secondary Schools in an International Perspective
PISA 2012 Key Findings
Thomas J. Alexander Fellowship
Photo source: Authors’ elaborations on PISA 2012 data, www.oecd.org/edu/Figure2.pdf