The question of private schools today occupies a unique place in the French educational debate. It also regularly returns to the center of public discussions, often during controversies surrounding the educational choices of the Ministers of National Education themselves. The sequence was repeated recently: Édouard Geffray, the new minister, enrolled his children in the private sector – like some of his predecessors, Amélie Oudéa-Castéra (January-February 2024) and Pap Ndiaye (May 2022-July 2023)
If these episodes attract so much attention, it is because they crystallize a tension that has become central: regularly credited with better academic results than the public sector, the private sector is largely financed by public funds while being authorized to select its students.
These differences in recruitment translate into massive differences in the social composition of establishments between public and private. This is shown by the social position indices (IPS), calculated by the Ministry of National Education by considering the socio-professional categories of the students’ parents.
The graphs below reflect these disparities, academy by academy. Take the example of Paris: the average GPI of public schools is around 118, compared to 143 in the private sector under contract, a gap of around 25 points, one of the highest in the country. In other words, Parisian private schools educate a public that is on average much more socially advantaged than public schools. The distributions also show that the private sector is concentrated at the top of the social scale, while the public sector welcomes a more heterogeneous population, with more students from modest backgrounds.
Do the better results of private schools in national assessments and exams really come from an “effect” specific to private education or do they primarily reflect the more advantaged social composition of its students?
Higher academic results in the private sector
International comparisons provide initial insight. The PISA assessments, carried out with 15-year-old students, remind us how France remains one of the countries where academic results depend the most on social background: almost a fifth of performance can be explained by social origin. In this context, private establishments – which welcome a more advantaged public on average – logically obtain better raw scores. But this is a snapshot, which says nothing about how students progress over time.
The differences between public and private relate to initial knowledge, but also to the way in which students progress during middle school.
When we stop looking only at performance at a given moment and follow students throughout their schooling, another observation emerges. From the beginning to the end of middle school, students educated in a private establishment progress more than those in the public school, from a comparable social background. This difference appears both in the sixth grade evaluations and in the final certificate grades: on average, academic trajectories improve more clearly in the private sector.
When we consider the final Brevet exams, in the graphs which follow, it appears that, in each subject, students educated in private schools under contract obtain on average higher grades than those in the public sector. The distributions also show that the results of public students are more dispersed, with more students in the lower part of the distribution.
By examining these paths in more detail, an additional element emerges: these differences are not uniform depending on the initial level. A recent study shows that the advantage observed at the end of third grade is more marked for students who are initially weaker, particularly in mathematics. In other words, the differences between public and private relate to initial knowledge, but also to the way in which students progress during middle school.
More marked progress throughout private schooling
Work carried out by the statistical service of the Ministry of National Education produced a very similar result. By following a cohort of CP students at the start of high school, its authors show that, in a comparable family and school context, progress in French and mathematics in middle school – especially in mathematics – is higher in the private sector than in the public sector.
These differences in progress cannot be explained by certain factors often put forward in public debate. The figures are unambiguous: private classes have an average of 27.2 students, compared to 24.7 in the public sector; the number of students per teacher is higher (14.6 compared to 12.8); and the private sector does not employ more aggregate teachers (4.5% compared to 13.4% in the public sector). Nothing in these management indicators therefore suggests more favorable conditions in the private sector.
Explanations must be sought elsewhere. Two avenues emerge. First, the social composition: private establishments welcome a more privileged public, which can mechanically increase results and make it possible to teach at higher levels. Then, the free recruitment of teachers, which makes it possible to form more coherent and more stable teaching teams, potentially better aligned on a common educational project – a framework which can also support a higher level of requirements.
A social composition that does not explain everything
Once these observations have been made, a central question remains: to what extent are public/private gaps explained simply by the much more advantaged social composition of private establishments? When we compare students of the same social origin and take into account not only their individual characteristics, but also the social composition of the establishments and classes in which they are educated, the advantage of the private sector over the public decreases only very slightly.
In practice, only 15 to 23% of the initial advantage is lost. In other words, social composition explains part of the difference… but certainly not all. Other factors are therefore at play.
It is students from modest backgrounds, although they are a very small minority in private education, who benefit the most from private schooling in terms of academic results.
The study reveals an essential point: social composition does not act in the same way depending on the origin of the students. For students from advantaged backgrounds, the apparent advantage of private education is mainly due to the fact that they are educated in colleges where the proportion of well-off students is significantly higher than in the public sector. Once we compare advantaged students enrolled in establishments with a similar social profile in the two sectors, the performance gap between public and private becomes almost zero. Nothing indicates, however, that these students derive their best performance from educational specificities specific to the private sector.
Conversely, for students from modest backgrounds, the situation is quite different: the advantage of private education remains clearly perceptible, even after neutralizing the effects of social background and school environment. Ultimately, it is these students, although they are a very small minority in the private sector, who benefit the most from private schooling in terms of academic results.
Questioning the fairness of the school system
Added to this is a question linked to the very functioning of establishments: if social composition only explains a modest part of the differences observed, where can we look for the remaining levers? One approach often put forward concerns the method of recruiting teachers, which is more flexible in the private sector: in the public sector, teachers are assigned by the administration, while in the private sector under contract it is the school heads who directly recruit the teachers, which leaves them more room to compose their teaching teams around the school project.
Nothing prevents us from examining what certain practices specific to the private sector – for example the freer recruitment of teachers by the head of the establishment – could inspire in the public sector, such as the recent experiment carried out as part of the “Marseille en grand” plan. This type of device remains poorly documented by research and constitutes a privileged area for future work.
Finally, can we consider sustainable a system where public money would, in fact, support an organization that contributes to reinforcing school segregation? The question deserves to be asked, if only in view of the very principles enshrined in the Education Code, according to which the public education service “contributes to equal opportunities and to combating social and territorial inequalities in terms of academic and educational success”.
The challenge now is to precisely document the mechanisms at work, in order to identify which levers of school organization could, ultimately, be mobilized in the service of greater equity in the education system.
