Choosing a Primary School: What the Research Actually Shows

Lead

"Does private school actually produce better outcomes?" The question surfaces every spring as school application seasons open, and it carries the same shape of anxiety whether a family is seriously considering private enrollment or just wondering from the sidelines.

How much of the observed gap between private and public school performance is actually the school's doing? What do researchers say when they press on that question seriously? And what factors beyond academic performance belong in the decision? This article organizes what the evidence shows.

A Note on Japan's School System

For readers unfamiliar with Japanese education: Japan distinguishes between three categories of primary school. Kōritsu (public) schools are administered and funded by local municipalities and constitute approximately 97% of all elementary schools nationally, making them the default for nearly all families [4]. Shiritsu (private) schools charge tuition, run their own admissions, and require a separate entrance process beginning before age six. Kokuritsu (national) schools are operated by national universities — typically as research and experimental settings — and are small in number; they sometimes accept children from affiliated university kindergartens. In the 2023 school year, private primary enrollment stood at roughly 1.3% of all primary students [4]. School selection is therefore a decision most Japanese families do not make — they attend the public school serving their address — while a smaller subset navigates the entrance-exam process for private or national schools.

"Private Schools Have Higher Scores" — Is That the School's Effect?

PISA data have repeatedly shown higher average scores among students in private schools compared with public schools [1]. The fact is real. The question is whether that gap reflects what the school does or which families' children enroll there.

Lubienski and Lubienski (2014) addressed this directly with a nationally representative US sample [2]. When they statistically adjusted for socioeconomic background, race, and home environment, the private school advantage — across both Catholic and non-religious private schools — disappeared. In mathematics, adjusted scores were actually higher in public schools [2].

The implication is substantial. Private schools' apparently superior performance reflects, on the available evidence, the characteristics of the students who attend — children from more advantaged home environments — rather than an effect of what those schools do educationally.

The OECD's own research team has produced consistent findings: across most participating countries, the private-public gap in PISA scores shrinks toward zero or reverses once socioeconomic background is controlled [1].

Why the Impression of Private-School Superiority Persists

Lubienski and Lubienski identify a second finding worth naming [2]. The argument that school-market competition and institutional autonomy — hallmarks of private schools — improve educational quality is not supported by the data. Private schools have greater latitude in teacher hiring and curriculum design than public schools, but that latitude did not translate into measurable learning advantages. By contrast, structured professional development for teachers and alignment with national curriculum standards — features more consistently present in public systems — showed positive associations with achievement.

Buchmann and Park (2009) found, across countries with highly differentiated educational systems, that what shapes long-term inequality most powerfully is not school type but the degree of stratification in the system — that is, the degree to which access to high-quality options is unequally distributed [3]. The concern is less "which type of school is better?" and more "who gets to choose at all?"

The Japanese Evidence

In Japan, families who enroll children in private primary schools tend to have higher economic and cultural capital on average — a pattern documented repeatedly in educational sociology research here. This means that, as in the international data, any raw comparison between private-school graduates and public-school graduates on long-term outcomes (university attendance, earnings) is likely to confound school effects with family effects. The two are not separable in observational data without strong methodological controls.

Reardon and Galindo's 2009 research on the US public school context, though focused on achievement gaps within public systems, is illuminating in this regard: home environment before school entry accounts for a large share of the variation in performance at school entry, and subsequent schooling has limited power to close that gap [5]. Stated differently, the home learning environment is already doing substantial work before any school-selection decision is made. A family that reads together, talks about ideas, and creates structured time for play is already exercising a strong influence on outcomes — one that school choice cannot easily replicate or negate.

What Else to Weigh

Research on school-type effects provides one axis of evidence; it does not provide a decision algorithm. There is also a methodological reason to be cautious about any study claiming to measure the long-term causal effect of school type on outcomes such as university attendance or career achievement. The selection problem — that families who choose private schools are systematically different from those who do not — is very difficult to design around in observational research. A study that finds "private-school graduates attend university at higher rates" cannot establish that attending a private school caused this outcome, as long as private-school families have higher academic expectations, more structured home environments, and greater financial resources for exam preparation. The school's contribution and the family's contribution are tangled [2,5].

The following are perspectives on what does belong in the decision — not a checklist.

Daily logistics and physical sustainability. A child will travel to this school every day for six years. Long commutes add fatigue and reduce time for unstructured activity. That is not a trivial variable.

Fit between the school's culture and the child's temperament. Some children find structure and competitive settings motivating; others develop more fully in a relaxed environment. School culture affects motivation and emotional well-being before it affects grades. And a child who dislikes school will not perform well regardless of which kind it is.

The cost to the family of the application process. Private school entrance in Japan involves preparation beginning years before enrollment — preparatory courses, formal interview preparation, and in many cases a significant financial commitment. Whether that process adds stress to the household is a real variable in the calculus. A high-quality education at the end of a stressful preparation year may be accompanied by a taxed family system.

Neighborhood networks. A local public school gathers the same-age children living nearby. After-school relationships, neighborhood community connections, and friendships that persist outside school hours are part of what public school provides — and they do not show up in any academic dataset.

Summary

The proposition that private schools produce better academic outcomes is not well supported once home background is controlled — the difference appears to reflect who attends, not what the school does [1,2]. Individual schools vary enormously in culture, resources, and human quality, and those differences are real. But evaluating them requires actually visiting individual schools rather than applying a public-versus-private shortcut.

The data offer one axis. The decision ultimately returns to a question no dataset answers directly: does this particular school, with this particular culture, fit this particular child?

References

1. OECD. PISA 2022 Results (Volume I): The State of Learning and Equity in Education. Paris: OECD Publishing; 2023. doi:10.1787/53f23881-en.
2. Lubienski CA, Lubienski ST. The Public School Advantage: Why Public Schools Outperform Private Schools. Chicago: University of Chicago Press; 2014. ISBN: 978-0-226-08891-4.
3. Buchmann C, Park H. Stratification and the formation of expectations in highly differentiated educational systems. Research in Social Stratification and Mobility. 2009;27(4):245–267. doi:10.1016/j.rssm.2009.04.004.
4. Ministry of Education, Culture, Sports, Science and Technology (MEXT). School Basic Survey, FY2023. 2023. https://www.mext.go.jp/b_menu/toukei/chousa01/kihon/1267995.htm
5. Reardon SF, Galindo C. The Hispanic-White achievement gap in math and reading in the elementary grades. American Educational Research Journal. 2009;46(3):853–891. doi:10.3102/0002831209333184.