Investing in Human Capital through Philanthropy: A Policy Review of the Onassis Foundation’s Initiative in Greek Public Schools

The paper examines the Onassis Foundation’s philanthropic investment of one hundred and sixty million euros, aimed at transforming twenty-two public lower- and upper-secondary schools into a high-quality network of Public Onassis Schools. The analysis is grounded in human capital theory, the economics of education, and the international literature on educational philanthropy, exploring how a large-scale private donation can influence public education policy, and support the improvement of public schooling. The study analyzes the school-based investments made by the initiative in infrastructure, curriculum enrichment, and teacher professional development, and compares them to similar international programs spearheaded by the Bill & Melinda Gates Foundation, the Jacobs Foundation, and Bloomberg Philanthropies. It is found that such public-private partnerships can enhance teaching quality and learning coherence and, at the economic level, strengthen the professional capital of teachers and generate long-term social returns through the enlargement of human capital. On the whole, the initiative is shown to offer an example of how a philanthropic investment channeled to a common vision can be a model of human-centered reform with practical educational and socioeconomic payoffs.

Introduction

The challenges confronting public education systems today are multifaceted and persistent and often require targeted capacity-building and additional resources that exceed routine public budgeting cycles. In this context, philanthropic entities and foundations have increasingly entered the public education arena as strategic investors, not as substitutes for public provision, but as complementary actors that may accelerate improvements through targeted capital, programmatic innovation, and implementation support. Through partnerships with governments and policymakers, philanthropic organizations may finance school infrastructure upgrades, roll out curricular enrichment initiatives, and support teachers and students with additional services, while simultaneously raising questions about governance, accountability, and equity in public systems.

The Onassis Foundation’s donation to the Greek public school system, designed to transform 22 public lower- and upper-secondary schools into a network of high-quality “Public Onassis Schools” (Onassis Foundation, 2025a), is a recent example of this international trend. This €160 million investment, carried out over a 12-year period, is expected to directly affect more than 6,000 students annually—or more than 22,000 students over the program horizon (Onassis Foundation, 2025b). Administered in partnership with the Greek Ministry of Education, the program is targeted at regions and cities with increased social and economic deprivation and is framed as a mechanism to expand access to high-quality public education. At the same time, because admissions follow an entrance-exam model (with municipal quotas intended to safeguard local access), the initiative constitutes a policy-relevant case for examining how excellence-oriented models can be reconciled with explicit equity objectives in a centralized public system. In this context, it is worth noting that Greek secondary education faces documented performance gaps relative to EU averages, particularly in mathematics and science literacy, as reflected in successive PISA cycles (OECD, 2019). These gaps disproportionately affect students from lower socioeconomic backgrounds and peripheral regions—precisely the populations the Onassis initiative targets.

The present study does not aim to evaluate the initiative’s impact (which would require longitudinal administrative and learning data), but to offer a structured academic policy review grounded in theory and international evidence. Specifically, this paper (a) provides a fact-based synthesis of the Onassis Foundation’s interventions in public schools, covering infrastructure, curriculum enrichment, teacher professional development and incentives, student support services, governance arrangements, and innovation initiatives; and (b) situates these interventions within the economics of education and the international literature on educational philanthropy, drawing on rigorous evidence from comparable cases to discuss plausible mechanisms, conditions for effectiveness, and foreseeable risks. Accordingly, this paper focuses on “expected” educational and socioeconomic returns (informed by prior empirical research) rather than measured outcomes in Greece, given the early stage of implementation.

Drawing on human capital theory and the economics of education, this study treats improvements in educational quality as investments with potentially high social returns (Hanushek & Kimko, 2000; Hanushek & Woessmann, 2012). It further draws on evidence regarding (i) the effectiveness of school capital investments, (ii) teacher professional development and coaching, and (iii) system-level reform dynamics and philanthropic influence in public policy. In addition, to strengthen causal reasoning without overstating certainty, the analysis is organized through a program-theory lens using a context–mechanism–outcome (CMO) configuration (Pawson & Tilley, 1997), considering how Greece’s centralized education governance and persistent school inequalities (context) interact with the initiative’s design features—resources, enrichment programs, professional development structures, incentives, and monitoring arrangements (mechanisms)—to produce anticipated improvements in learning, equity, and broader developmental outcomes (outcomes).

Against this background, the present study offers an academic review of the Onassis Foundation’s large-scale philanthropic investments in Greek public secondary education, examining its design and mechanisms and discussing its expected implications through the lenses of human capital theory, the economics of education, and international evidence on educational philanthropy. Specifically, this study addresses the following research question:

How and under what governance and equity conditions can a large-scale philanthropic investment in public secondary education, implemented through a structured public–private partnership, plausibly contribute to educational improvement, human capital formation, and long-term socioeconomic returns in a centralized public system?

This academic review is structured into five sections. First, the Theoretical Framework synthesizes scholarship in the economics of education, educational administration, and educational reform to specify the causal pathways and boundary conditions through which philanthropic interventions may influence learning, human capital formation, and governance in public systems. Second, the Review Methodology outlines the integrative review design, covering the search strategy, inclusion/exclusion criteria, source appraisal, and synthesis procedures (Torraco, 2016; Whittemore & Knafl, 2005)—and justifies the selection of the three international reference cases (Gates, Jacobs, Bloomberg) as analytically contrasting models of educational philanthropy. Third, the Analysis section provides a structured account of the Public Onassis Schools initiative and examines its intervention components (infrastructure, curriculum enrichment, human resources, incentives, and governance arrangements) against evidence from the international cases, with explicit attention to implementation fidelity, equity risks, and monitoring requirements. Fourth, the Discussion section distills the main insights, identifies policy-relevant trade-offs (excellence–equity, innovation–accountability, and sustainability–dependency), and clarifies the conditions under which expected effects are most plausible. Finally, the Conclusion summarizes the contribution of the review and proposes a forward-looking evaluation agenda, including independent longitudinal designs, transparent key performance indicator (KPI) reporting, and cost–benefit simulations, to estimate potential socioeconomic returns once outcome data become available.

Theoretical Framework

The philanthropic model examined in this study is grounded in human capital theory and the economics of education. From this perspective, improving the quality of an educational system constitutes an investment with potentially high social returns. The macroeconomic literature shows that students’ cognitive skills, used as a proxy for learning quality, are strongly associated with long-term economic growth, and that improvements in learning outcomes have a substantially stronger growth-enhancing effect than increases in years of schooling alone (Hanushek & Kimko, 2000; Hanushek & Woessmann, 2012).

At the microeconomic level, empirical evidence indicates that school quality and the learning environment are associated with higher future earnings and improved labor-market outcomes, although traditional input-based indicators do not fully capture the underlying mechanisms (Betts, 1995; Card & Krueger, 1992; Ioakimidiset al., 2020; Rizzuto & Wachtel, 1980). The broader literature on the rates of return to education further confirms that educational attainment yields substantial private and social returns across countries and over time (Psacharopoulos & Patrinos, 2018).

Within this theoretical framework, the Onassis Foundation’s intervention is justified as an investment with the potential to strengthen human capital formation and support long-term economic development.

Beyond macroeconomic considerations, it is important to examine how educational interventions financed through targeted capital investments affect learning outcomes. International evidence indicates that well-directed spending on school infrastructure can improve student performance. One of the most comprehensive evaluations to date, Biasiet al. (2024), shows that large-scale school capital investments in the United States lead to statistically significant gains in student achievement. In particular, investments related to the physical modernization of schools, laboratories, and STEM equipment are associated with improvements in test scores.

Approximately eight years after implementation, elementary students’ test scores increased by approximately 0.08 standard deviations, with socio-economically disadvantaged districts benefiting disproportionately from these investments. The findings suggest that improvements in the quality of the learning environment—such as facilities, equipment, and basic infrastructure—can have meaningful pedagogical effects that support student learning.

The literature consistently highlights the central role of teachers in improving learning outcomes. Well-designed professional development initiatives that strengthen teachers’ instructional capacity can lead to sustained improvements in teaching quality and student achievement. A widely cited review commissioned by the U.S. Department of Education shows that intensive professional development (averaging approximately 50 h) is associated with meaningful gains in student learning (Yoonet al., 2007).

Subsequent research emphasizes that effectiveness depends primarily on the quality of professional development, particularly when it is sustained, collaborative, and focused on supporting teachers in translating new ideas into classroom practice (Kennedy, 2016). A recent meta-analysis of causal studies further confirms that teacher coaching has positive effects on instruction and more moderate effects on student achievement, while also highlighting the challenges of maintaining effectiveness at scale (Kraftet al., 2018). Philanthropic initiatives, such as the Onassis Schools Project, can help mobilize the resources required to support high-quality professional development. Beyond classroom-level mechanisms of teaching and professional development, the literature also conceptualizes philanthropy as a system-level reform actor, capable of influencing governance structures, institutional capacity, and the pace of educational change.

The literature on educational innovation emphasizes that sustainable reform requires coordinated, system-level interventions rather than isolated initiatives (Fullan, 2006; 2011). From this perspective, philanthropic foundations may act as accelerators of change by providing flexible resources and supporting innovation at a pace that is often difficult for public systems to achieve. This role has been described as venture philanthropy, characterized by investment-oriented strategies and convergent grant-making in support of specific reform agendas (Reckhow & Snyder, 2014; Scott, 2009).

Meanwhile, critical scholarship highlights potential challenges related to accountability and democratic legitimacy, particularly when private actors exert disproportionate influence over public education policy. This body of work underscores the need for institutional oversight to ensure that philanthropic interventions are integrated sustainably and do not generate new forms of inequality or dependency (Au & Ferrare, 2014).

In brief, the literature reviewed above suggests that large-scale philanthropic interventions can contribute to educational improvement and broader developmental outcomes when embedded within coherent public education systems. Research on educational reform and philanthropic engagement indicates that such interventions may act as catalysts for change rather than substitutes for public policy.

Across this literature, three recurring conditions emerge as critical for effectiveness: (a) high-quality program design, grounded in evidence on infrastructure, teaching, and curriculum; (b) close collaboration with the public sector, including alignment with national curricula and coordinated implementation; and (c) systematic monitoring of outcomes to support learning, accountability, and adaptive implementation. The following section examines the extent to which these conditions are reflected in the Onassis Foundation program and draws lessons from comparable international experiences.

Research Methodology

This study is based on the method of an integrative literature review (Torraco, 2016; Whittemore & Knafl, 2005), which seeks to gather, evaluate, and synthesize both theoretical and empirical sources concerning philanthropic investments and interventions in education and their documented or expected outcomes. An integrative review was selected because it allows the combination of diverse forms of evidence—including peer-reviewed empirical studies, policy reports, program evaluations, and theoretical contributions—within a coherent analytical framework.

A structured and reproducible search strategy was implemented across four major databases—Scopus, Web of Science, ERIC, and Google Scholar—to ensure comprehensive coverage of the economics of education, education policy, and educational philanthropy literature. The final search was completed in November 2025 and covered the period 2000–2025, with an emphasis on post-2010 publications reflecting contemporary philanthropic governance models and impact-evaluation methodologies.

The search strategy combined three conceptual clusters using Boolean operators. The first cluster captured philanthropy-related terms: (“education philanthropy” OR “venture philanthropy” OR “philanthrocapitalism” OR “nonprofit investment” OR “foundation-funded education”). The second cluster captured intervention domains: (“school infrastructure” OR “educational facilities” OR “teacher professional development” OR “instructional coaching” OR “curriculum enrichment” OR “public–private partnership”). The third cluster captured outcome and economic terms: (“student achievement” OR “learning outcomes” OR “human capital” OR “economic returns” OR “cost–benefit analysis” OR “longitudinal impact” OR “quasi-experimental” OR “randomized controlled trial”). These clusters were combined using the structure: (Cluster 1) AND (Cluster 2) AND (Cluster 3). Database-specific filters were applied to limit the results to peer-reviewed journal articles, evaluation reports with explicit methodology, and publications in English or Greek.

Inclusion criteria were defined as follows:

(a) peer-reviewed empirical studies examining the impact of philanthropic or externally funded educational interventions; (b) rigorous program evaluations (randomized controlled trials, quasi-experimental studies, longitudinal analyses, or independent institutional evaluations); (c) major policy reports from recognized international organizations (e.g., OECD) or foundations with transparent methodologies; and (d) theoretical contributions relevant to human capital theory, educational reform, and philanthropic governance.

The exclusion criteria were purely descriptive accounts without evaluative components, opinion pieces, and sources lacking methodological transparency.

Regarding the Onassis Foundation, firsthand sources of the foundation itself were utilized (Onassis Foundation, 2025a,b), along with press releases and relevant legislation, to provide an accurate account of the scope, design, and governance structure of the initiative. These primary documents were treated as program design data rather than outcome evidence. Secondary data were drawn from international evaluations and case studies of comparable initiatives, including the RAND evaluation of the Gates Foundation’s Intensive Partnerships for Effective Teaching (Stecheret al., 2018), independent MDRC studies of the Small Schools of Choice reform (Bloom & Unterman, 2013), the academic evaluation of Bloomberg Philanthropies’ Summer Boost program (Bloomberg Philanthropies, 2024), and reports documenting the Jacobs Foundation’s systemic initiatives (Jacobs Foundation, 2020; 2023). Particular emphasis was placed on evidence derived from quantitative evaluations, including randomized trials, quasi-experimental designs, and measurable performance indicators, to ground the analysis in verifiable findings rather than purely narrative accounts.

The international examples (Gates, Jacobs, Bloomberg) were chosen for their representation of three distinct models of educational philanthropy: large-scale reform-oriented investments (Gates), research-driven systemic partnerships (Jacobs), and targeted municipal performance programs (Bloomberg). The cases were selected through purposive sampling to maximize variation in governance structure, scale, and reform strategy, thereby strengthening the comparative analytical dimension of the study.

The synthesis of evidence followed a qualitative comparative approach. Sources were thematically coded along four analytical dimensions: (1) intervention design (infrastructure, curriculum, human resources, governance), (2) implementation mechanisms, (3) measured educational outcomes, and (4) reported systemic or socioeconomic effects. This matrix-based comparison allowed the Greek initiative to be examined alongside international cases in a structured manner.

An additional analytical layer was provided through the use of the context–mechanism–outcome (CMO) configuration from program theory (Pawson & Tilley, 1997). Specifically, the Greek centralized education system and its structural inequalities were conceptualized as the contextual layer; the Onassis intervention components (additional financial resources, extended curriculum, professional development, incentives, and governance arrangements) were conceptualized as mechanisms; and anticipated improvements in learning outcomes, equity indicators, and human capital formation were conceptualized as outcomes. This framework enables causal reasoning without claiming direct empirical attribution, which would require longitudinal outcome data. Regarding the weighting of evidence, quantitative evaluations (randomized and quasi-experimental designs) were treated as the primary evidentiary tier. Policy reports and program documents—including the Onassis Foundation donation contract—were used exclusively as program design data, not as outcome evidence, and were interpreted in light of the broader empirical literature rather than taken at face value.

It is important to clarify that the present study does not constitute an impact evaluation and does not generate new primary data. Rather, it offers a theory-informed and evidence-grounded policy assessment of expected outcomes based on international empirical findings and documented program design features. Consequently, the conclusions should be interpreted as analytically derived projections under stated conditions, rather than as measured causal effects within the Greek context.

Finally, as a literature-based investigation, the study adheres to standard ethical principles of academic research, including transparent citation of all sources, balanced presentation of both positive and negative evidence, and avoidance of normative advocacy beyond what is supported by documented findings.

Results

Interventions of the Onassis Foundation in Greek Public Education

Education has been a priority for the Onassis Foundation for decades, since Aristotle Onassis made his first donations for scholarships and awards. Donations and support continued in fields such as research, culture, lifelong learning, and education through the programs of Onassis Stegi. However, the establishment of the Public Onassis Schools was the largest and most comprehensive systemic intervention in secondary education. In a donation agreement signed on January 20, 2025, the President of the Onassis Foundation, Antonis Papadimitriou, and the Greek State agreed to upgrade 22 public schools (11 lower- and 11 upper-secondary) in Greece and operate them as model schools under the name “Public Onassis Schools.” The 22 Public Onassis Schools were selected based on their geographical location and the social characteristics of their community. In particular, in areas of Attica (Kolonos, Kypseli, Menidi, Perama, Peristeri) and in regional districts (Kordelio–Evosmos and Xirokrini in Thessaloniki, Kozani, Xanthi, Rhodes, Heraklion), in places with serious social and economic problems where there was no access to a model or experimental school.

(Onassis Foundation, 2025a) The key dimensions of the intervention are as follows:

Building and Renovation Works and Equipment

The 22 schools will be completely renovated and equipped. Up to €1 million will be available per school for building work. The schools’ buildings will be renovated to create a modern and functional learning environment with state-of-the-art science laboratories, arts spaces, libraries, and IT rooms. (As underlined before, “the Onassis Schools are equipped with next-generation technology, improved laboratories, and renovated buildings that create an environment enhancing students’ educational experience”). Special attention will be given to digital infrastructure (interactive boards, high-speed Internet connection, specific software), accessibility (ramps, elevators, and disability support), and the aesthetic renovation of the schools’ spaces to provide warm, welcoming, and functional spaces.

Curriculum Enrichment and STEAM Development

The Public Onassis Schools operate within the national curriculum while retaining flexibility for approved curriculum enrichment (Governing Committee of the Public Onassis Schools, n.d.). The program emphasizes 21st-century competencies, including humanities, digital literacy, social–emotional learning, and STEAM (science, technology, engineering, arts, and mathematics).

Curriculum enrichment is implemented through “Groups and Clusters,” which provide at least ten additional hours per week of structured activities beyond the regular timetable. These include advanced STEM subjects (robotics, programming, laboratory sciences), enhanced Greek language instruction, foreign languages, arts and culture (visual arts, music, theatre), and supplementary courses supporting preparation for national examinations.

Participation is mandatory, ensuring non-selective access to enriched learning opportunities. As noted by the Onassis Foundation, these activities aim to “open horizons in sciences, the Greek language, digital technology, the arts, and culture” (Onassis Foundation, 2025b), supporting broad skill development and student engagement.

Teacher Professional Development and Incentives

Teachers in the Public Onassis Schools will be supported through a professional development framework fully funded by the Onassis Foundation, including training in Greece or abroad and targeted scholarships. During the transition period (2025–2027), existing staff will remain in their posts and participate in training aligned with the philosophy and requirements of the Onassis Schools, while subsequent staffing will follow the national Model Schools selection procedures based on merit and interviews.

In parallel, financial incentives are provided for participation in groups and clusters. Teachers will retain their standard public-sector workload and salary and receive an additional €320 for six weekly hours devoted to these activities, funded by the Onassis Foundation. The intervention also includes funding for specialized support staff, such as psychologists and social workers, to address students’ additional educational and social needs.

Extracurricular Programs and Further Innovations

The Onassis Foundation’s funding extends beyond infrastructure and teaching staff to cover the operational costs of extracurricular programs delivered outside the regular timetable. Each school will receive up to €500,000 annually to support enrichment activities such as student groups, educational visits, collaborations with universities, competitions, and the development of educational materials, ensuring free and equal access for all students.

A key innovation is the pilot integration of artificial intelligence in education. In collaboration with the Ministry of Education and OpenAI, the Foundation supports the use of a specialized educational version of ChatGPT (ChatGPT Edu) in 20 upper-secondary schools, including six Onassis Schools. This initiative includes funded teacher training and the provision of a secure, GDPR-compliant digital environment to support pedagogically responsible experimentation with AI tools.

More broadly, the Onassis Schools are intended to function as centers of educational innovation, exploring new teaching methods, digital tools, hybrid learning models, and experiential approaches, with the overarching aim of implementing innovative educational programs based on pioneering pedagogical practices.

Governance and Public–Private Cooperation

The governance structure of the project is of great importance. Although the schools receive financial and material support from the Onassis Foundation, they remain public in every aspect. Teachers are civil servants, students will not pay, and all the schools remain under the supervision of the Ministry of Education. To balance public authority with philanthropic involvement, a nine-member Management Committee is established. Five members are appointed by the Ministry, and four are appointed by the Foundation. This committee, headquartered at the Ministry, oversees the schools’ compliance with high operational standards and monitors goal achievement. It is explicitly clarified that “the Onassis Foundation does not intervene in the functioning or teaching content of the schools” (Onassis Foundation, 2025b, question 3).

The governance architecture of the Public Onassis Schools aligns with established principles of good school governance, which empirical research has shown to be critical for decision-making quality at the school level. In addition, effective governance arrangements depend on the extent to which school leaders can exercise informed decision-making within clearly defined institutional frameworks.

Student Access and Social Inclusion

Although the Onassis Schools remain fully public, admissions follow the entrance exam model applied to model schools. Final-grade primary and lower-secondary students sit standardized exams, while social inclusion is ensured through municipal quotas of 40%–60%, reserving a substantial share of places for local students regardless of slightly lower exam performance. Existing students continue through graduation, and attendance is free, with all educational provisions covered.

This admission framework seeks to balance academic excellence with social equity, responding to the exceptionally high demand for Model and Experimental Schools in Greece, where in 2024, more than 20,300 applications competed for approximately 4,800 places. The Onassis initiative is expected to expand the number of such schools by approximately 50%, increasing access to high-quality public education across regions.

The collaboration is framed as a public–private partnership serving the public interest, comparable to earlier Onassis Foundation initiatives operating as public institutions, such as the Onassis Cardiac Surgery Center (Papadimitriouet al., 2006). Academic literature highlights the foundation’s long-standing philanthropic philosophy, which conceptualizes donations as instruments of public benefit and long-term social development rather than privatization (Papadimitriou, 2002).

In addition, the Onassis Schools will be connected with neighboring schools, allowing for broader student participation in selected activities. Overall, the intervention represents a long-term, integrated approach combining infrastructure investment, pedagogical innovation, human support, and community engagement, underpinned by a 12-year commitment to sustainability (ERT News, 2025).

Investment in Teacher and Leadership Capacity

One of the most distinctive features of the Onassis Foundation’s intervention is its direct financial investment in school staff, complementing expenditures on infrastructure and technology. This approach shifts the philanthropic model from a predominantly capital-centered logic towards a human-centered strategy that directly supports the human resources of Greek public secondary education. Under the Donation Agreement, supplementary monthly allowances are provided to staff involved in extended school activities: €400 for principals, €350 for vice-principals, €320 for teaching staff, and €300 for psychologists, social workers, school nurses, and IT specialists, with additional remuneration for summer work (Onassis Foundation, 2025a, art. 8).

Unlike dominant international models of educational philanthropy that prioritize infrastructure, programs, or technology, the Greek case combines capital investment with direct support for personnel. This dual focus signals a human-centered logic that recognizes teachers and school leaders as primary drivers of educational improvement. Such practices remain rare internationally, as contemporary educational philanthropy tends to emphasize systemic reforms and policy influence rather than direct salary enhancement (Hess & Henig, 2015; Tompkins-Stange, 2020).

This strategy aligns with extensive evidence showing that teaching quality and school leadership constitute the most powerful in-school determinants of student learning, exceeding the impact of infrastructure or curriculum alone (Hanushek, 2013; Hanushek & Woessmann, 2020; Hattie, 2008). Financial incentives, when embedded in structured professional frameworks, can strengthen motivation, professional commitment, and participation in professional development (Desimone, 2009; Kraftet al., 2018; Murnane & Cohen, 1986). Targeted support for leadership further reflects research emphasizing leadership capacity as central to sustainable reform (Leithwoodet al., 2020).

Overall, additional remuneration functions not merely as a financial benefit but as a strategic investment in professional capital and institutional capacity (Hargreaves & Fullan, 2015). By combining infrastructure funding with human-centered incentives, the Onassis initiative represents an internationally distinctive model of educational philanthropy that reframes schools from physical assets to communities of professionals. In the longer term, such incentives are expected to generate multiplier effects through improved teaching quality, higher job satisfaction, staff stability, and strengthened human capital development (Psacharopoulos & Patrinos, 2002).

Expected Educational Outcomes and Returns

International evidence suggests that the core components of the Onassis Schools intervention have a high likelihood of improving learning outcomes, provided that implementation is of high quality. Investments in school facilities and equipment are associated with statistically significant gains in achievement, particularly when directed towards laboratories, educational technology, and learning environments that support contemporary pedagogical practices (Lafortuneet al., 2024). In the context of the Onassis Schools, the effective use of modern infrastructure is expected to generate medium-term improvements in mathematics and science achievement, while also enabling differentiated and personalized instruction. Comparable initiatives, such as New York’s Small Schools of Choice, have demonstrated higher graduation rates relative to traditional schools, with effects observable within three to five years (Bloom & Unterman, 2013).

A second set of anticipated outcomes relates to curriculum enrichment through STEM activities, the arts, and supplementary instruction. International research consistently shows that enriched learning environments positively affect student engagement, socio-emotional development, and academic outcomes. Evidence from a large-scale study in Houston indicates that increased exposure to the arts and cultural programs is associated with higher writing achievement, greater empathy and social understanding, and fewer disciplinary incidents (Bowen & Kisida, 2019). Accordingly, the Onassis Schools’ emphasis on the arts, culture, collaborative pedagogies, and structured preparation for national examinations is likely to enhance school climate, student engagement, and university admission prospects.

The third major mechanism concerns investments in teachers, which is widely regarded as the most influential in-school factor affecting learning. Professional development combined with financial incentives is expected to translate into improved instructional practices, including differentiated instruction, project-based learning, and more effective use of assessment data. Such investments may also enhance job satisfaction, professional recognition, and teacher motivation, which are closely linked to instructional effectiveness (Hargreaves & Fullan, 2015). At the same time, international experience cautions against short-term expectations. The evaluation of the Gates Foundation’s Intensive Partnerships for Effective Teaching found no statistically significant effects on student outcomes despite substantial investment (Stecheret al., 2018), a finding that was widely discussed in the policy debate (Will, 2018). These results underscore that meaningful instructional change requires time, coherence, and sustained support rather than isolated interventions. In contrast to large-scale reforms, the smaller scale and integrated design of the Onassis Schools, aligned with new organizational structures and pedagogical innovations, increase the likelihood of gradual but substantial improvements in teaching quality, initially reflected in student engagement, attendance, classroom participation, and reduced performance gaps among vulnerable groups.

A fourth expected outcome concerns the reduction of educational inequalities. As the Onassis Schools are primarily located in socioeconomically disadvantaged areas and reserve a substantial share of places for local students, the intervention targets communities with historically limited access to high-quality schooling. International evidence shows that students in low-resource schools experience systematically weaker outcomes, even after controlling for individual socioeconomic background (OECD, 2019). Over time, higher completion and university entry rates may contribute to reducing educational and social inequalities through strengthened human capital formation (Psacharopoulos & Patrinos, 2018).

Overall, the anticipated impact of the Onassis Foundation’s investment can be understood across two time timeframes (see Table I). In the short to medium term (2–5 years), improvements are expected in school climate, student engagement, parental satisfaction, foundational skills, and conventional indicators, such as attendance and progression. In the longer term (beyond five years), outcomes may include higher graduation and university entry rates, stronger preparation for tertiary education and the labor market, and a gradual narrowing of achievement gaps. A further systemic effect may arise through the diffusion of successful practices, enabling selected innovations from the Onassis Schools—such as activity-based grouping and new models of teacher development—to inform broader public education policy.

Table I. Overview of Expected Educational Outcomes by Time Frame

Domain	Short to medium term (2–5 years)	Long term (beyond 5 years)
School climate & engagement	Improved attendance, parental satisfaction, student participation	Sustained school culture of excellence; model for broader reform
Academic outcomes	Gains in foundational skills (maths, science); reduced performance gaps	Higher graduation & university entry rates; narrowing achievement gaps
Teaching quality	Improved instructional practices; higher job satisfaction & motivation	Strengthened professional capital; staff stability; multiplier effects on student outcomes
Equity	Expanded access to high-quality public schooling in deprived areas	Reduced social inequalities through human capital formation; systemic diffusion of practices

Anticipated Economic and Socio-Developmental Benefits

Βeyond educational outcomes, the Onassis initiative is expected to generate broader economic and socio-developmental benefits through human capital formation. Improvements in educational quality and cognitive skills are strongly linked to long-term economic growth, employability, and productivity (Hanushek, 2013; Hanushek & Woessmann, 2012; 2020). Even moderate gains in student achievement have been shown to produce measurable macroeconomic returns.

At the individual level, graduates of the Public Onassis Schools are likely to experience improved academic trajectories, higher university participation, and increased lifetime earnings. Empirical evidence consistently shows that attendance at higher-quality schools translates into better labor-market outcomes, even after controlling for socioeconomic background (Chettyet al., 2014; Kane & Staiger, 2008). Given the disadvantaged background of many incoming students, these gains are particularly significant.

At the local level, the establishment of high-performing schools in disadvantaged areas may stimulate economic activity through infrastructure investments, job creation, and increased demand for local goods and services. Although modest in national terms, the €160 million investment is expected to have tangible neighborhood-level effects. International evidence also indicates that improvements in school quality are associated with rising property values and neighborhood revitalization, as households respond to anticipated educational gains (Lafortuneet al., 2018).

At the national level, the initiative constitutes a targeted investment in future workforce productivity. Research shows that gains in learning outcomes and learning-adjusted years of schooling are among the strongest predictors of long-term economic performance (Angristet al., 2021; Hanushek & Woessmann, 2012, 2023). In Greece, where demographic decline and economic restructuring present major challenges, providing high-quality education to approximately 30,000 students may yield non-negligible productivity benefits and serve as a pilot for scalable reforms.

Beyond economic returns, improved education quality is associated with positive social externalities, including lower crime rates, better health outcomes, stronger civic engagement, and greater social cohesion (Cutler & Lleras-Muney, 2010; Lochner & Moretti, 2004; Oreopoulos & Salvanes, 2011; Putnam, 2007). In disadvantaged areas, high-quality schools can reduce the risks of social exclusion and delinquency, generating long-term savings in public expenditure.

In summary, the anticipated impact of the Onassis Foundation initiative spans multiple time horizons: short-term local economic stimulus, medium-term human capital strengthening, and long-term gains in productivity, social cohesion, and growth. These outcomes, however, are contingent on effective implementation, sustained commitment, and systematic monitoring to ensure that the projected benefits materialize.

International Precedents of Philanthropic Investments in Education: Cases and Results

To contextualize the Onassis Foundation initiative in a comparative perspective and extract meaningful lessons, this section provides three international examples of major nonprofit investments in education along with their respective quantifiable results. These examples were chosen to capture and present a variety of approaches and, where possible, from different parts of the world: (1) the Bill & Melinda Gates Foundation in the US, which invested heavily in K–12 programs (Bloomet al., 2010); (2) the Jacobs Foundation in Switzerland, which embraced an evidence-driven, rigorous approach with long-term commitments and strategic partnerships with government bodies (Jacobs Foundation, 2017, 2023; Jacobs Foundation, n.d.); and (3) Bloomberg Philanthropies in New York, which provides grants for school reform and more focused learning recovery programs, such as Summer Boost (Summer Boost, 2025; Bloomberg Philanthropies, 2024). These examples offer a variety of successes and failures that are relevant to our case in Greece.

The Bill and Melinda Gates Foundation

The Gates Foundation has spent billions on US K–12 education. A well-known case of Gates funding is the Small Schools of Choice (SSCs) reform in New York City. The reform closed down large, low-performing high schools and replaced them with new smaller public high schools, with approximately 400 students each, new staff, and support from intermediary organizations (Bloomet al., 2010).

An independent MDRC evaluation of this reform, based on the lottery-based admissions process, found that SSCs increased four-year graduation rates by approximately 9.5% compared to similar students in other high schools (Bloom & Unterman, 2013; Unterman & Haider, 2019). Improvements were present for a large range of student subgroups, such as students with special educational needs and English language learners (Bloom & Unterman, 2013; Unterman & Haider, 2019). Research points to effective leadership and a coherent pedagogical identity, better teacher–student relationships, and systematic use of partnerships and data as possible explanations for the success of small schools (Bloomet al., 2010).

In contrast, the Intensive Partnerships for Effective Teaching initiative (2009–2015), which cost approximately $575 million, did not generate similar outcomes. The program rolled out complex teacher evaluation systems that combined rubric-based classroom observations, value-added measures, and differentiated compensation. An independent final evaluation by RAND and AIR found no discernible impact on student achievement, graduation rates, or disadvantaged students’ access to more effective teachers. The analysis underlined problems with the program’s implementation, such as resistance among teachers, political instability, and the overall complexity of the reform design that restricted its effectiveness (Stecheret al., 2018).

The key lesson is that interventions operating directly at the level of the school environment can generate strong effects, whereas reforms targeting employment structures are far more difficult to implement successfully. For the Onassis Foundation, this reinforces the strategy of upgrading school units in partnership with the state without generating conflict with educators.

The Jacobs Foundation

The Jacobs Foundation adopts a systemic, evidence-based approach focused on long-term partnerships and a 500 million CHF investment commitment in its Strategy 2030 (Jacobs Foundation, n.d.). The flagship case of Transforming Education in Cocoa Communities (TRECC) took place in Côte d’Ivoire, a country with low education indicators in rural cocoa-growing communities. The program was designed and evaluated in collaboration with organizations such as Innovations for Poverty Action, which recorded modifications in various revealing areas. These included measurements in early childhood development, reading instruction, and parental empowerment. The International Cocoa Initiative supplied complementary analyses and synthesized important lessons learned, as well as the institutional implications of the five-year program (International Cocoa Initiative, 2021).

The Foundation created a government–business–organization partnership and outsourced evidence generation to Innovations for Poverty Action (Innovations for Poverty Action, 2025). Interventions on early education, literacy instruction, and parental engagement were tested and evaluated using robust methodologies (Jacobs Foundation, 2017). Only after being proven effective were they scaled with an eye towards government adoption ( poverty-action.org). Investments in evidence labs and policy evaluation systems have built the institutional capacity of the Ministry of Education (OECD, 2019).

In Switzerland, the Foundation promotes Bildungslandschaften, networks of schools, municipalities, and community stakeholders, with positive results on cooperation and the development of shared goals (Jacobs Foundation, 2023). An important comprehensive lesson is that philanthropic interventions must create durable, long-lasting mechanisms and institutions.

In Greece, where the public school system is highly institutionalized, the Jacobs experience is a reminder of the importance of shared ownership. The Onassis Foundation has issued specific declarations that it does not intend to replace the state but instead to partner with it (Onassis Foundation, 2025a,b).

Bloomberg Philanthropies

Bloomberg Philanthropies directs its efforts toward data-driven educational interventions, often partnering with public schools. In the post-COVID-19 era, it broadened the Summer Boost program to reach tens of thousands of students from poorer families in sites across the United States (Schwartz, 2025). A 2023 program evaluation showed favorable results: compared to similar non-participating students, participants gained additional learning in math and reading equivalent to 4–5 weeks and 3–4 weeks, respectively. There was evidence of summer learning as well, with evidence of cumulative impacts for students who received the intervention during two consecutive summers, as well as a “sticky effect” a year after the program (Bloomberg Philanthropies, 2024). External evaluations deemed the program an example of an encouraging model of summer learning (Toppo, 2024).

The main lesson to be drawn from Bloomberg’s interventions is the importance of goal-setting, continuous evaluation, and close collaboration with public school systems. In the Greek context, this calls for the annual measurement of the key indicators of graduation, learning gaps, and participation in innovative programs and continued investment in supplementary educational components, such as clubs and experiential labs, in the Public Onassis Schools (Onassis Foundation, 2025a).

Table II presents a brief comparative overview of the philanthropic initiatives discussed above.

Table II. Comparative Overview of Major Philanthropic Initiatives in Education

Dimension	Onassis foundation (Greece)	Gates foundation (USA)	Jacobs foundation (CH/Global)	Bloomberg philanthropies (USA)
Scale	€160M/22 schools/12 years	$575M+/national K–12 programs	500M CHF/Strategy 2030/global	City-level programs; tens of thousands of students
Governance model	Joint Management Committee (5 Ministry + 4 Foundation); full public oversight	Foundation-led; intermediary organizations; limited state control	Gov–business–NGO partnership; evidence outsourced to IPA	Data-driven partnerships with public school systems; external evaluation (Harvard)
Primary mechanism	Infrastructure + curriculum + direct human capital investment (salaries)	Large-scale reform (SSCs); teacher evaluation systems	Evidence-based systemic reform; scale-up only after proof of effectiveness	Targeted programs (summer learning); KPI-driven; continuous measurement
Key results	Pending (early stage); projected via CMO framework	SSCs: +9.5% graduation rate; teacher eval program: no detectable effect on students	Positive impacts in literacy, early childhood, parental engagement in TRECC; systemic capacity built	+4–5 weeks maths gains; +3–4 weeks reading gains; “sticky” effect after 1 year

Discussion

This review highlights both the potential and challenges associated with the Onassis Foundation’s investment in Greek public education, situating it within an international landscape of comparable initiatives. Overall, the Public Onassis Schools constitute a coherent and ambitious intervention that simultaneously addresses the main levers of educational improvement— infrastructure, curriculum, teachers, and additional resources—while explicitly pursuing the dual objectives of excellence and equity. The scale of the donation (€160 million), unprecedented in the Greek education system and equivalent to approximately 2% of annual public expenditure on secondary education, creates a rare opportunity to accelerate reforms that would otherwise require decades.

Expected educational outcomes are promising but not automatic. International experience shows that similar investments can generate gains in achievement, reductions in inequalities, and skill enrichment only when supported by strong school leadership, collaborative professional cultures, and the active engagement of parents and students, as illustrated by the Gates small schools reform. In the case of the Onassis Schools, particular attention must be paid to the risk of student “creaming” resulting from entrance examinations. While the quota system represents an important safeguard, complementary measures, such as providing academic support to lower-achieving students from neighboring schools, may be necessary to ensure that the original social mission of supporting vulnerable students is preserved.

The political economy of educational reform in Greece constitutes a critical contextual layer that the CMO framework must account for. Greek teacher union have historically played an influential role in shaping and at times resisting reform initiatives, particularly when these involve differentiated pay, extended working hours, or changes to civil servant status. The supplementary allowances offered under the donation agreement represent a departure from the uniform salary grid of the public sector, which, although welcomed by individual teachers, may generate broader institutional tensions if not managed carefully. Similarly, the multiparty parliamentary support for the initiative does not fully insulate it from political volatility; a change of government or a shift in union relations could affect implementation fidelity, particularly in the post-2037 sustainability phase. These dynamics do not negate the initiative’s potential but underscore that successful implementation will require proactive stakeholder management and sustained political commitment. Sustainability remains a critical challenge, given the time-limited nature of the donation. Lessons from the Jacobs Foundation underscore the importance of early exit planning, whereby the state gradually assumes responsibility for sustaining successful program components. Although the governance structure, anchored within the Ministry of Education, supports this direction, greater clarity is required regarding post-2037 financial commitments, scaling strategies, and whether successful elements will be expanded system-wide or selectively adopted (e.g., activity clubs across junior high schools). An independent evaluation with clearly defined key performance indicators—such as academic progress, university admissions, satisfaction, and dropout reduction—is therefore essential. To operationalize this agenda, a proposed set of KPIs could include: (1) annual student achievement scores in mathematics and language (standardized, relative to control schools); (2) four-year graduation and university admission rates, disaggregated by socioeconomic background; (3) student attendance and dropout rates; (4) teacher retention and professional development participation rates; (5) school climate indices based on annual surveys of students, parents, and staff; and (6) share of students from the municipal quota who meet academic progression benchmarks. These indicators should be reported publicly each year to support accountability and adaptive management.

The public–private collaboration model also raises questions of political legitimacy. Despite broad multiparty support in Parliament, concerns persist about the emergence of a “parallel system.” Although political leaders, including the Greek Prime Minister Kyriakos Mitsotakis as well as the President of the Onassis Foundation, Antonis Papadimitriou, have emphasized that the initiative aims to strengthen rather than replace public education, perceptions will ultimately depend on practice. To avoid elite isolation, the Onassis Schools should function as hubs of knowledge diffusion, enabling participation from surrounding schools, supporting wider teacher professional development, and ensuring open access to educational materials. Such mechanisms are crucial for achieving systemic rather than isolated impact.

Another important challenge concerns the quantification of economic returns. Although the impacts are indirect and long-term, cost–benefit simulations—such as estimating lifetime income gains and associated fiscal returns for approximately 22,000 graduates—could provide robust justification for continuation or expansion, following established U.S. practices in education policy analysis (Heckman, 2006; Heckmanet al., 2010). Such an analysis would likely demonstrate multiple returns on investment and strengthen public and political support.

The national context further shapes the initiative’s prospects. Greece’s centralized education system limits flexibility but enables more uniform implementation, whereas the predominance of public schooling suggests that successful scaling could generate stronger system-wide externalities than in more fragmented systems. Moreover, the engagement of a highly respected philanthropic organization may help establish a new tradition of educational philanthropy, analogous to how the Onassis Cardiac Surgery Center set a precedent for public–private partnerships in the health sector. Alongside earlier initiatives by the Stavros Niarchos Foundation and the Latsis Foundation, coordinated and complementary action—potentially through a formal forum involving major foundations and the Ministry—could enhance coherence and effectiveness.

Finally, innovation inevitably entails risk and uncertainty. Underperformance, community tensions, or unintended consequences of selection mechanisms require flexibility and timely corrective action. Continuous communication with students, parents, and teachers, systematic use of feedback, and broader representation of school leaders or teachers within governance structures can strengthen responsiveness. Transparency is equally essential. Annual public reporting on funding use, student demographics, activities, and evaluation results would enhance accountability and trust, while collaborations with universities—such as those underpinning Bloomberg’s Summer Boost evaluation by Harvard—could ensure objectivity and attract international scholarly attention.

Overall, the Onassis Foundation investment emerges as both an opportunity and a challenge: an opportunity to upgrade public education at scale and serve the long-term interests of thousands of young citizens, and a challenge in terms of design, implementation, sustainability, and effective learning from international experience. If successful, it could become a model for educational reform in Greece and potentially internationally, much as the Onassis Cardiac Surgery Center became a reference point for public–private partnerships in the health sector.

Conclusions

The philanthropic investment of the Onassis Foundation in Greek public education, through the creation and support of 22 Public Onassis Schools, constitutes an intervention of unprecedented scale and scope for the country. This review examined the initiative’s key dimensions, ranging from infrastructure and pedagogical modernization to teacher development and social objectives. The analysis indicates that such a holistic investment has the potential to generate substantial benefits, including improved learning quality, stronger school outcomes, enhanced educational capital in vulnerable areas, and broader economic and social gains through human capital development.

Taken together, the evidence reviewed in this study provides a clear answer to the research question posed. It suggests that large-scale philanthropic investments in public secondary education, when implemented through a structured public–private partnership, can contribute meaningfully to educational improvement, human capital formation, and long-term socioeconomic returns, while remaining aligned with public governance and equity objectives—provided that strong institutional collaboration, coherent program design, and continuous evaluation mechanisms are in place.

At the same time, success will not occur automatically. International experience shows that philanthropic interventions can lead to transformative outcomes but also face significant challenges. Evidence from the United States and Europe—from the strong results of New York’s small schools to the limited impact of the Gates teacher evaluation initiative—highlights the decisive role of program design, leadership, and stakeholder collaboration. In this respect, the Onassis initiative appears to incorporate key lessons from prior experience: it operates in close partnership with the Ministry of Education, strengthens rather than bypasses public schooling, and commits to a long-term horizon that allows outcomes to be assessed over time. The result is a hybrid reform model in which public governance and funding structures are complemented by targeted private resources and innovation.

If successful, the benefits of this model will be multidimensional. Educationally, it may demonstrate that public schools can achieve high quality and international competitiveness when adequately supported. Socially, it offers pathways of advancement for students from disadvantaged backgrounds, contributing to greater social cohesion and equity. Economically, it may support the development of a skilled workforce aligned with the needs of a knowledge-based economy, thereby enhancing national competitiveness and growth potential. Institutionally, the initiative could also serve as a template for future public–private collaborations, either by encouraging additional philanthropic engagement or by informing broader public-sector reforms.

Overall, the academic evidence reviewed supports a cautiously optimistic outlook regarding the potential payoffs of the Onassis Foundation investment. At the same time, it underscores the importance of careful implementation, continuous evaluation, and adaptive management. Independent longitudinal studies, conducted by universities or research institutes, are therefore strongly recommended to capture the full range of educational and economic impacts, including long-term returns on investment. Such evidence would not only inform the refinement of this program but also enrich the international literature on the economics of education by providing a case study from a middle-income country.

In conclusion, the Onassis Foundation investment represents a historic opportunity for Greek education. It offers the possibility of redefining what public schooling can achieve, grounded in the principle that every child, regardless of location or background, deserves access to high-quality education. Although this vision cannot be realized overnight or by a single actor, the potential benefits for the education system and for society at large make the endeavor a compelling and worthwhile undertaking.

Conflict of Interest

The author declares no conflicts of interest.