Even short school breaks affect student learning unevenly across socioeconomic backgrounds

Researchers show that students from low-income households, specifically boys, were the most affected, highlighting growing educational inequality

Waseda University

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In Japan, short-term class closures due to localized influenza outbreaks adversely affected the math test scores of elementary school boys from low-income households, likely due to reduced in-school instructional time and detrimental habits like excessive TV-watching. However, high-quality teachers and remedial education programs could reduce the adverse impact of class closures on disadvantaged students. 

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Credit: Assistant Professor Masato Oikawa from Waseda University, Japan

The COVID-19 pandemic affected people worldwide disproportionately, with economically disadvantaged households facing a heavier burden. Children were also affected since schools and classes were closed to contain the virus. Many students, especially from disadvantaged backgrounds, lost their learning environments, and their academic performance suffered. However, the pandemic presented other challenges that may have also affected students, such as parents losing jobs, financial stress at home, and parents not having the option to work from home. So, it is unclear how class closures alone could have impacted students’ academic outcomes.

To gain more insights, a research team led by Assistant Professor Masato Oikawa from School of Education, Faculty of Education and Integrated Arts and Sciences, Waseda University, Japan, investigated the effect of class closures due to influenza epidemics on students’ mathematics and language test scores in the following year post-closure. They also studied the effect across different socioeconomic backgrounds. The team included Professor Ryuichi Tanaka from The University of Tokyo and Professor Shun-ichiro Bessho, Professor Akira Kawamura, and Professor Haruko Noguchi from Waseda University. Their study was made available online on September 3, 2025, and will be published in Volume 78 of the Journal of the Japanese and International Economies on December 1, 2025.

“Since the COVID-19 pandemic involved many complex factors, we were inspired to use a natural experiment by looking at pre-pandemic data on routine class closures due to seasonal, localized influenza outbreaks. These were short-term disruptions, with classes closed for an average of 2 to 3 days per month. This allowed us to separate the specific impact of unscheduled loss of instruction time from other confounding factors,” explains Oikawa.

To this end, researchers used administrative data from 2015 to 2017 of all public elementary and middle schools located in a city in the Tokyo Metropolitan Area. The data was collected by the city’s education board and included information such as test scores and lifestyle factors. Furthermore, researchers categorized students receiving financial support—offered by local governments to attend school—as belonging to low-income households and those not receiving it as belonging to middle-to-high income households. Using an econometric model, the team then estimated the impact of class closures on students’ academic performance.

Researchers found that students from disadvantaged backgrounds were most susceptible to the negative effects of class closures. These negative effects on disadvantaged students differed by gender, subject, grade level, timing of closures, and past academic performance.

Class closures had a significant negative impact on the math scores of elementary school boys. The effect was more pronounced among boys with low test scores at the start of the school year, and for class closures during the last two months of the school year (February and March). These findings highlight the higher vulnerability of economically disadvantaged boys, likely due to reduced in-school instructional time as well as detrimental habits, such as increased time watching television and playing video games, low sleep quality, and decreased study time during closures.

However, smaller class sizes (fewer than or equal to 30 students) and teachers with more years of experience teaching in the current school could reduce the adverse effects of class closures, especially among disadvantaged students.

“This research reveals that even common, short-term disruptions like flu-related class closures can widen the performance gap. These findings can be directly applied to education policy and school administration. Schools could prepare online materials in advance and provide remedial support to classes that experienced closures, especially those with a high proportion of economically disadvantaged students. Parents must maintain their children's daily routines, particularly regarding screen time and sleep, during unexpected school breaks,” emphasizes Oikawa.

Hopefully, the study pushes education systems to be more resilient, even against temporary disruptions, to protect students’ learning opportunities and reduce educational inequality.

 

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Reference
Authors: Masato Oikawa1,2, Ryuichi Tanaka3, Shun-ichiro Bessho4, Akira Kawamura5,2, and Haruko Noguchi4,2
DOI: 10.1016/j.jjie.2025.101387
Affiliations: 1Faculty of Education and Integrated Arts and Sciences, Waseda University
2Waseda Institute of Social & Human Capital Studies (WISH)
3Institute of Social Science, The University of Tokyo
4Faculty of Political Science and Economics, Waseda University
5Faculty of Human Sciences, Waseda University

 

About Waseda University
Located in the heart of Tokyo, Waseda University is a leading private research university that has long been dedicated to academic excellence, innovative research, and civic engagement at both the local and global levels since 1882. The University has produced many changemakers in its history, including eight prime ministers and many leaders in business, science and technology, literature, sports, and film. Waseda has strong collaborations with overseas research institutions and is committed to advancing cutting-edge research and developing leaders who can contribute to the resolution of complex, global social issues. The University has set a target of achieving a zero-carbon campus by 2032, in line with the Sustainable Development Goals (SDGs) adopted by the United Nations in 2015. 

To learn more about Waseda University, visit https://www.waseda.jp/top/en  

About Assistant Professor Masato Oikawa from Waseda University
Masato Oikawa is an Assistant Professor (tenure-track) at the Faculty of Education and Integrated Arts and Sciences at Waseda University, Japan. He received his doctorate in Economics from The University of Tokyo in 2019. His research focuses on health economics, the economics of education, and applied microeconometrics. He has published his work in several international journals, including Journal of Health Economics, American Journal of Health Economics, and Child Abuse & Neglect. He is also a member of numerous academic associations, including the Econometric Society and the Japanese Economic Association. In 2017, he received the Excellent Paper Award at the 12th Applied Econometrics Conference.

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Journal

Journal of the Japanese and International Economies

DOI

10.1016/j.jjie.2025.101387 

Method of Research

Observational study

Subject of Research

People

Article Title

Do class closures affect students’ achievements? Heterogeneous effects of students’ socioeconomic backgrounds

Article Publication Date

1-Dec-2025

COI Statement

This study was conducted as part of the Project ‘‘Microeconometric Analysis of Education Policy with Large Administrative Data’’ undertaken at the Research Institute of Economy, Trade and Industry (RIETI). This study utilized school administrative data collected by the Education Board of City X. This study was funded by the Japan Society for the Promotion of Science (JSPS) KAKENHI Grant-in-Aid for Scientific Research (A) ‘‘Scientific Evidence on Children’s Human Capital Creation and Its Implementation: Development of Policy Assessment Process by Government-Academia Collaboration’’ (Project Number: 19H00602) and a preceding grant (Project Number: 16H03636). In addition, Tanaka received funding from JSPS (Project Number: 20H05629).

 

When words matter: Language and culture shape early childhood outcomes

Zhejiang University

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Developmental vulnerability among CALD and non-CALD children. A population-based study of nearly 60,000 children in Western Australia revealed that those from CALD backgrounds faced higher developmental vulnerability. Compared with their peers, CALD children were more than twice as likely to show difficulties in communication skills and general knowledge, and were also at greater risk in language and cognitive development. The findings highlight the need for culturally responsive policies and targeted early childhood support to bridge developmental gaps.

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Credit: World Journal of Pediatrics

Children entering school from culturally and linguistically diverse (CALD) families are more likely to face developmental challenges than their peers, according to a large population-based study in Western Australia. Researchers found that nearly one in four CALD children displayed vulnerabilities in at least one key developmental domain, with communication skills and general knowledge showing the largest gaps. These difficulties go beyond the classroom, shaping social integration, self-confidence, and long-term educational opportunities. The findings highlight the urgent need for tailored early support, ensuring cultural and language differences do not create lasting disadvantages for children at a critical stage of growth.

Early childhood is a decisive period that sets the foundation for learning, socialization, and health across the lifespan. Developmental vulnerabilities—such as delays in communication, language acquisition, or social competence—can hinder school readiness and reduce future opportunities. For children growing up in multicultural households, additional challenges often compound these risks. Limited English proficiency, cultural isolation, and socioeconomic stress can make it harder to access early education, healthcare, or supportive networks. Evidence from international studies echoes these patterns, showing that immigrant and minority children frequently face gaps in learning and social development. Because of these challenges, further research is needed to better understand developmental vulnerability among culturally and linguistically diverse (CALD) children.

On July 9, 2025, a research team from Curtin University, the University of Adelaide, and international collaborators published (DOI: 10.1007/s12519-025-00936-0) their findings in the World Journal of Pediatrics. The study analyzed outcomes for more than 10,000 CALD children alongside nearly 50,000 non-CALD peers using linked administrative datasets. Results revealed that CALD children had 23% greater odds of being developmentally vulnerable, with the starkest disparities in communication and language-based skills. The findings illustrate how cultural and linguistic differences, though enriching to society, can translate into measurable challenges for children at the start of school life.

Drawing on three rounds of the Australian Early Development Census, combined with birth and hospital records, the study assessed children’s progress at around age five across five developmental domains: physical health, social competence, emotional maturity, language and cognitive skills, and communication and general knowledge. Results showed that 23.7% of CALD children were vulnerable in at least one domain, compared to 19.6% of non-CALD children. Particularly striking were disparities in communication and general knowledge, where CALD children faced more than double the risk, and in language and cognitive skills, where they had 37% higher odds of vulnerability. Interestingly, non-CALD children showed greater vulnerability in physical health, highlighting contrasting developmental pressures. Further analysis confirmed that language spoken at home, maternal ethnic background, and country of birth all contributed to these outcomes. The study also revealed sharper risks for CALD girls than boys, pointing to a complex interplay of cultural, gender, and social factors. Together, the findings reveal how structural disadvantages—language barriers, economic hardship, and unequal access to services—shape the developmental trajectory of multicultural children.

“Our research shows that cultural and language differences are not peripheral—they profoundly influence children’s ability to thrive when they start school,” said Dr. Gizachew A. Tessema, co-author of the study. “Children from CALD families face double the risk of vulnerability in communication and language development. Without targeted support, these early gaps can grow into lifelong inequalities. Addressing these disparities requires culturally sensitive education policies, stronger language support, and better collaboration between families, teachers, and health professionals. Every child deserves an equal chance to succeed, regardless of their cultural background.”

The study calls for urgent investment in culturally responsive early childhood programs. Providing bilingual learning materials, training teachers in cultural competence, and ensuring equitable access to preschool and healthcare could close the developmental gap. Policymakers are urged to recognize CALD children as a priority group for early intervention, with strategies to identify vulnerabilities before they become entrenched. Although these initiatives require resources, they are cost-effective by reducing the need for remedial education and improving long-term outcomes. By supporting CALD children from the start, societies can promote inclusion, strengthen educational equity, and build healthier, more resilient communities.

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References

DOI

10.1007/s12519-025-00936-0

Original Source URL

https://doi.org/10.1007/s12519-025-00936-0

Funding information

Open Access funding enabled and organized by CAUL and its Member Institutions. TGA was funded by the Australia National Health and Medical Research Council (#1195716). PG was funded by the Australia National Health and Medical Research Council (#1099655 and #1173991).

About World Journal of Pediatrics

Published monthly, the World Journal of Pediatrics offers peer-reviewed original papers, reviews and special reports focusing on clinical practice and research in pediatrics. The journal presents contributions on new developments in all areas of the discipline from pediatricians worldwide. Coverage includes the most current progress in pediatrics, pediatric surgery, preventive health care in pediatrics, pharmacology, stomatology and biomedicine. The journal also covers basic sciences and experimental work, and provides a broad academic platform for the international exchange of medical results.

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Journal

World Journal of Pediatrics

DOI

10.1007/s12519-025-00936-0 

Subject of Research

Not applicable

Article Title

Developmental vulnerability in children from culturally and linguistically diverse backgrounds in Western Australia: a population-based study

 

Birds’ vocal warnings provide new insight into the origins of language

Cornell University

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ITHACA, N.Y. – Birds separated by vast geographic distances and millions of years of evolution share a remarkably similar learned vocal warning to identify parasitic enemies near their nests, an international team of researchers has found.

The results represent the first known example of an animal vocalization that is learned from an innate response shared across multiple species.

The findings, which will publish October 3, 2025 at 5am EST in Nature Ecology and Evolution, provide a glimpse into the role natural selection can play in the evolution of vocal communication systems. The study, led by researchers at Cornell University and Donana Biological Station in Seville, Spain, is one of the largest and most comprehensive studies concerning brood parasites to date.

Brood parasitism occurs when birds, such as cuckoos, lay their eggs in other species’ nests, forcing the host to raise their young, often at the expense of the host’s own offspring. That’s why it is advantageous for the host species to identify and try to prevent nest parasites from laying eggs.

The researchers found that more than 20 different bird species across four continents produce nearly identical “whining” vocalizations when they spot a parasitic bird in their territory.

The researchers wondered why birds from locations spanning Australia, China and Zambia all use the same call to identify their parasites, despite never coming into contact with each other.

When a bird hears the warning call, it instinctively comes to investigate. That’s when, according to the researchers, the birds start absorbing the cues around them – what Damián Blasi, co-author of the study and a language scientist at Pompeu Fabra University, Spain, calls social transmission.

“It’s then, when birds are absorbing the clues around them, that the bird learns when to produce the sound in the future,” said James Kennerley, co-lead author and postdoctoral fellow at the Cornell Lab of Ornithology.

“The fascinating thing about this call is that it represents a midpoint between the instinctive vocalizations we often see in animals and fully learned vocal units like human words,” said William Feeney, an evolutionary ecologist at Donana Biological Station in Seville, Spain, and co-lead of the study.

The research also revealed species that produce the whining call tend to live in areas with complex networks of interactions between brood parasites and their hosts.

“With birds working together to drive parasites away, communicating how and when to cooperate is really important, so this call is popping up in parts of the world where species are most affected by brood parasitism,” said Kennerley.

The result, he said, “is that the evolution of the whining vocalization is affecting patterns of cooperative behaviors between birds around the world.”

The link between the innate whining sound and the learned response by the bird is what makes this study unique, the authors said. “For the first time, we’ve documented a vocalization that has both learned and innate components, potentially showing how learned signals may have evolved from innate calls in a way first suggested by Charles Darwin,” Feeney said. “It’s like seeing how evolution can enable species to give learned meanings to sounds.”

The findings challenge long-held assumptions about the sharp division between animal communication systems and human language. The authors suggest that learned communication systems, like human language, may have evolved through the gradual integration of instinctive and learned elements.

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Journal

Nature Ecology & Evolution

DOI

10.1038/s41559-025-02855-9 

Article Title

Learned use of an innate sound-meaning association in birds'

Article Publication Date

3-Oct-2025