Sverre Berg Ofstad

• Rayner, Christopher; Hannigan, Laurie; Badini, Isabella; Demange, Perline Aline Delle; Ofstad, Sverre Berg & Ystrøm, Eivind [Show all 7 contributors for this article] (2026). Quantifying and adjusting for selection biases in the Norwegian Mother, Father and Child Cohort Study using population-wide individual-level registry information. International Journal of Epidemiology. ISSN 0300-5771. 55(4). doi: 10.1093/ije/dyag122. Full text in Research Archive Show summary

  Background Selective participation in research studies hampers researchers’ ability to draw valid and generalizable inferences from analyses. Quantifying and adjusting for selective participation are desirable but can be challenging given the paucity of data for non-participants. Methods We used individual-level information from population registers to predict baseline and continued participation in the Norwegian Mother, Father and Child Cohort Study (MoBa). Inverse probability weights were computed from logistic regression models with elastic-net regularization. We predicted selective participation and attrition in 296 987 mothers, of whom 29% returned the first MoBa questionnaire and 12.5% returned a follow-up questionnaire 8 years later. To quantify bias, we computed sample characteristics and exposure–outcome associations in the target population and stratified samples. To compare approaches for adjusting for bias, we computed weighted sample estimates by using three sets of weights. Results Unweighted sample estimates were systematically different from target-population values, indicating bias due to selective participation. Baseline participation weights substantially reduced the impact of selection bias on mean values by 93% and associations by 75%. Attrition weights reduced attrition bias on mean values by 78% and associations by 50% but were less effective for reducing participation bias (22% and 14% respectively). Conclusion In this sample, characteristics and effect estimates are substantially different from target-population values. Participation weights were relatively effective at reducing bias due to selective participation but attrition weights were not. Estimates from studies that use attrition weights may still contain non-negligible selection bias—particularly if the baseline sample is not representative of the target population. Future studies should prioritize opportunities for deriving sampling weights for participation as well as attrition.

• Ofstad, Sverre Berg; Tan, Tony & Andersson, Björn (2026). Comparing the difficulty of elective subjects in high school using a population-based Norwegian registry. Scandinavian Journal of Educational Research. ISSN 0031-3831. doi: 10.1080/00313831.2026.2648976. Full text in Research Archive Show summary

  When grade point averages (GPAs) are used for admission into tertiary education, there is an implicit assumption that any two identical GPAs convey the same level of academic competency. However, this assumption does not hold when students are free to choose elective subjects and there are differences in their difficulty and dimensionality. In this study, we utilized item response theory to examine dimensionality and difficulty of 11 elective subjects in Norwegian high school, while accounting for self-selection bias, using data from 21,666 third year students. Our results show that the GPA is best represented as a multidimensional construct. Additionally, we demonstrate that the selection bias in observed subject grade averages for electives conceals considerable differences in difficulty levels. Hence, the GPA of Norwegian high school students does not only reflect academic competency but also the decisions made regarding which elective subjects to take.

• Emslander, Valentin; Holzberger, Doris; Ofstad, Sverre Berg; Fischbach, Antoine & Scherer, Ronny (2025). Teacher-Student Relationships and Student Outcomes: A Systematic Second-Order Meta-Analytic Review. Psychological bulletin. ISSN 0033-2909. 151(3), p. 365–397. doi: 10.1037/bul0000461. Full text in Research Archive Show summary

  Teacher–student relationships (TSRs) play a vital role in establishing a positive classroom climate and promoting positive student outcomes. Several meta-analyses have suggested significant correlations between positive TSRs and, for example, academic achievement, motivation, executive functions, and well-being, as well as between negative TSRs that result in behavior problems or bullying. These meta-analyses have differed substantially in TSR–outcome relationships, moderators, and methodological quality, thus complicating the interpretation of these findings. In this preregistered systematic review of meta-analyses plus original second-order meta-analyses (SOMAs), we aimed to (a) synthesize the meta-analytic evidence on relations between TSRs and student outcomes, (b) map influential moderators of these relations, and (c) assess the methodological quality of the meta-analyses. We synthesized over 70 years of educational research across 26 meta-analyses encompassing 119 meta-analytic effect sizes based on approximately 2.64 million prekindergarten and K–12 students. We conducted several three-level SOMAs and found that TSRs had similar large significant relations with eight clusters of student outcomes: academic achievement, academic emotions, appropriate student behavior, behavior problems, executive functions and self-control, motivation, school belonging and engagement, and well-being. The link with bullying was only marginally significant. Our moderator analyses suggested a larger TSR–outcome link for middle and high school students. Although more recent meta-analyses fulfilled more methodological quality criteria, these differences were not associated with TSR–outcome relations. These results map the field of TSR research; present their relations, moderators, and methodological quality in meta-analyses; and show how TSRs are equally important for a wide range of student outcomes and samples.

• Ofstad, Sverre Berg & Marin, Andrei Florin (2019). 'What exactly are we a part of now?' Norwegian NGOs' engagement with state governmentality. Forum for Development Studies. ISSN 0803-9410. 46(3), p. 429–450. doi: 10.1080/08039410.2019.1593240. Full text in Research Archive Show summary

  Non-governmental Organizations (NGOs) have risen to the forefront of the development sector. Yet, for a group of development actors that are explicitly non-governmental, it is conspicuous that their rise to prominence owes itself to state funding. This conundrum has spurred a debate about whether NGOs represent the poor and marginalized, or the states that funds them. This debate is highly topical today as donor states increasingly conflate development policy with other policy fields, a process often referred to as ‘the new humanitarianism’. Here, we contribute to this debate by exploring the relationship between Norwegian humanitarian NGOs and the Norwegian state. Through semi-structured interviews with 10 Norwegian NGOs, we investigated how the state and NGOs influence each other. By using a Foucauldian approach to the study of governance, we find that the state shapes NGOs by orienting their activities towards professionalism and quantifiable targets. NGOs, however, are not passive, but continuously try to mold the structures of their relationship with the state in a plethora of ways. Nonetheless, the new humanitarianism is inserting a new rationality into the Norwegian aid system, where NGOs reorient their activities to achieve security and foreign policy objectives. As a result, many Norwegian NGO workers find their activities compromised. The new humanitarianism, with its potential for a holistic approach to development, has instead undermined the practices of Norwegian NGOs.

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• Ofstad, Sverre Berg; Peng, Qiyuan; Ebeltoft, Joakim; Bjørndal, Ludvig Daae; Rayner, Christopher & Ayorech, Ziada [Show all 10 contributors for this article] (2026). PGI-by-Environment interactions: practical guidelines for robust research. Full text in Research Archive
• ofstad, Sverre; Demange, Perline; Qin, Qi; Cheesman, Rosa; Torvik, Fartein Ask & Ystrom, Eivind (2026). How Schools Can Narrow the Gender and Genetic Gaps in Educational Achievement. Research Square. ISSN 2693-5015. doi: 10.21203/rs.3.rs-8592276/v1. Full text in Research Archive Show summary

  Abstract Boys have received lower average grades than girls for over a century, with likely implications for their future educational opportunities, mental health, and mortality. However, there are also considerable achievement differences within both gender groups, largely owing to individual differences in cognitive and non-cognitive skills. Identifying mechanisms within schools that shape educational gaps related to both gender and skills could reveal approaches to support all struggling students, regardless of gender. We computed polygenic indices for cognitive and non-cognitive skills for a sample of 36,800 Norwegian students across 1,068 lower secondary schools, leveraging genetic variation as an exogenous source of student skills through a within-family design. By interacting the polygenic indices with gender and a wide range of population-representative school environments, we find that some school environments provide additional benefits for students with lower non-cognitive predispositions. This compensatory support was especially pronounced for boys. Additionally, while both gender groups benefited from the same school environments, effects were generally larger for boys. Taken together, our results indicate that schools may reduce educational achievement differences within and across gender groups by reducing the influence of non-cognitive predispositions on achievement.

• Ofstad, Sverre Berg; Demange, Perline Aline Delle; Ayorech, Ziada; Valstad, Mathias & Ystrom, Eivind (2026). Temporal Trends in the Severity and Impairment of Childhood and Adolescent ADHD: A Population-Wide Genetic Study in Norway. Full text in Research Archive Show summary

  By calculating family genetic risk scores for the entire for the entire Norwegian population for birth years 1992-2019, ages 6-16 (N ≈ 1.5M) we show that the reduction in functional impairment over time is largely attributed to a diagnostic expansion of less genetically severe cases. Those who are diagnosed today have lower levels of genetic risk, while simulatenously, there has been no change in the relationship between GPA at age 16 and genetic risk for ADHD.

• Bjørndal, Ludvig Daae; Valstad, Mathias; Eilertsen, Espen Moen; Ayorech, Ziada; Ofstad, Sverre Berg & Salvatore, Jessica E. [Show all 8 contributors for this article] (2026). Peer effects contribute to psychiatric disorder risk: A population-wide study. Full text in Research Archive
• Ofstad, Sverre Berg; Demange, Perline Aline Delle; Ayorech, Ziada; Valstad, Mathias & Ystrom, Eivind (2026). Temporal Trends in the Severity and Impairment of Childhood and Adolescent ADHD: A Population-Wide Genetic Study in Norway. Full text in Research Archive Show summary

  By calculating family genetic risk scores for the entire for the entire Norwegian population for birth years 1992-2019, ages 6-16 (N ≈ 1.5M) we show that the reduction in functional impairment over time is largely attributed to a diagnostic expansion of less genetically severe cases. Those who are diagnosed today have lower levels of genetic risk, while simulatenously, there has been no change in the relationship between GPA at age 16 and genetic risk for ADHD.

• Ofstad, Sverre Berg; Tan, Tony & Andersson, Björn (2025). Comparing Elective Subject Difficulty Using a Joint Item Response Theory Model. Full text in Research Archive
• Ofstad, Sverre Berg; Demange, Perline Aline Delle; Torvik, Fartein Ask; Cheesman, Rosa Catherine Gillespie; Qin, Qi & Ystrøm, Eivind (2025). Using within-family polygenic indexes to examine sex-specific gene-environment interaction on GPA. Full text in Research Archive
• Ofstad, Sverre Berg; Demange, Perline Aline Delle; Cheesman, Rosa Catherine Gillespie; Qin, Qi; Torvik, Fartein Ask & Ystrøm, Eivind (2025). from DNA to GPA: a genetically informed study of the male disadvantage in schools. Full text in Research Archive
• Qin, Qi; Ystrøm, Eivind; Eilertsen, Espen Moen; Ofstad, Sverre Berg; Ayorech, Ziada & Cheesman, Rosa Catherine Gillespie (2024). School-level Moderation of Multiple Within- Family Polygenic Index Effects on Educational Performance in MoBa (n=27476 Trios). Full text in Research Archive
• Ystrøm, Eivind; Cheesman, Rosa Catherine Gillespie; Hootegem, Arno Van; Ghirardi, Gaia; Ofstad, Sverre Berg & Ebeltoft, Joakim Coleman (2024). Roads less traveled in social science genetics. Full text in Research Archive
• Emslander, Valentin; Levy, Jessica; Ofstad, Sverre Berg; Rosa, Cassie & Fischbach, Antoine (2024). The National Education Report for Luxembourg 2024: Instructional Quality and School Climate in Luxembourg's Écoles Fondamentales - Findings from the SIVA Study. Full text in Research Archive
• Qin, Qi; Ystrøm, Eivind; Eilertsen, Espen Moen; Ofstad, Sverre Berg; Ayorech, Ziada & Cheesman, Rosa Catherine Gillespie (2024). School-level Moderation of Multiple Within- Family Polygenic Index Effects on Educational Performance in MoBa (n=27476 Trios). Full text in Research Archive
• Ofstad, Sverre Berg; Demange, Perline Aline Delle; Cheesman, Rosa Catherine Gillespie; Qin, Qi & Ystrøm, Eivind (2024). Nature Meets Schooling: Why Boys Fall Behind in GPA Despite Equal Genetic Potential (ESSGN). Full text in Research Archive
• Ofstad, Sverre Berg; Demange, Perline Aline Delle; Cheesman, Rosa Catherine Gillespie; Qin, Qi & Ystrøm, Eivind (2024). Sex-specific gene x school interactions found by using within-family polygenic score and twin modelling. Full text in Research Archive
• Ofstad, Sverre Berg; Demange, Perline Aline Delle; Cheesman, Rosa Catherine Gillespie; Qin, Qi & Ystrøm, Eivind (2024). Nature Meets Schooling: Why Boys Fall Behind in GPA Despite Equal Genetic Potential. Full text in Research Archive
• Ofstad, Sverre Berg & Andersson, Björn (2026). Karakterulempen ved å velge realfag: I hvilken grad veier realfagspoengene opp for den? Universitetet i Oslo. doi: https:/www.uv.uio.no/cemo/english/about/news-events-and-publications/news/2026/bonus-points-natural-science.html. Full text in Research Archive

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