New results from the OECD’s 2018 Programme for International Student Assessment (PISA) show that public schools across the OECD achieve better results than private schools and that school systems with larger private school sectors have lower student achievement.
After accounting for students’ and schools’ socio-economic profile, students in public schools scored higher in reading than students in private schools, on average across OECD countries (by 14 score points). At the system level, across all countries and economies, school systems with larger private sectors had lower average performance in reading, mathematics and science.
Public schools achieved significantly better results than private schools in nine OECD countries after adjusting for differences in socio-economic profile. Public schools did as well as private schools in the 21 other countries, including Australia, for which results could be compared. Private schools did not achieve better results than public schools in any OECD country.
Australia has one of the largest private school sectors in the world. In 2018, private schools enrolled 42% of all secondary students compared to the OECD average of 18%. The only countries with a larger private sector are Chile (66%), Netherlands (64%) and the UK (66%).
The raw results show that 15-year-old private school students are about a year or more ahead of their public school peers. However, Australia has one of the most socially segregated school systems in the OECD. There is a much greater concentration of low socio-economic status (SES) students in public schools and a much greater concentration of high SES students in private schools.
The PISA data show that 96% of low SES students attend public schools compared to only 24% of high SES students. Public schools enrol the lowest proportion of high SES students in the OECD except for Chile and the UK. In contrast, 76% of high SES students are in private schools. This is the largest proportion in the OECD except for Chile. Spain and the UK.
The high concentration of low SES students in public schools and the high concentration of high SES students in private schools accounts for the difference in raw results between the sectors. Low SES students have much lower average results than high SES students in Australia equivalent to about three years of learning.
The PISA analysis found that after adjusting for the large difference in the socio-economic profile of public and private schools there is no difference in results. Public schools in Australia do as well as private schools even though they have far fewer resources than private schools and government funding policies have heavily favoured private schools.
The policy priority should be to target more resources to disadvantaged students in public schools to improve results for disadvantaged students and reduce inequity in education. If public schools were resourced as well as private schools they could emulate other OECD countries where public schools do better than private schools.
Data are available from OEDC, PISA 2018 Results (Volume V): Effective Policies, Successful Schools, OECD Publishing, Paris, Online tables V.B1.7.1, V.B1.7.4, V.B1.7.5 & V.B1.7.6.