Abstract In recent years, increased stakeholder pressure to transition research to Open Access has led to many journals converting, or ‘flipping’, from a closed access (CA) to an open access (OA) publishing model. Changing the publishing model can influence the decision of authors to submit their papers to a journal, and increased article accessibility may influence citation behaviour. In this paper we aimed to understand how flipping a journal to an OA model influences the journal’s future publication volumes and citation impact. We analysed two independent sets of journals that had flipped to an OA model, one from the Directory of Open Access Journals (DOAJ) and one from the Open Access Directory (OAD), and compared their development with two respective control groups of similar journals. For bibliometric analyses, journals were matched to the Scopus database. We assessed changes in the number of articles published over time, as well as two citation metrics at the journal and article level: the normalised impact factor (IF) and the average relative citations (ARC), respectively. Our results show that overall, journals that flipped to an OA model increased their publication output compared to journals that remained closed. Mean normalised IF and ARC also generally increased following the flip to an OA model, at a greater rate than was observed in the control groups. However, the changes appear to vary largely by scientific discipline. Overall, these results indicate that flipping to an OA publishing model can bring positive changes to a journal.
Our results show that overall, journals that flipped to an OA model increased their publication output compared to journals that remained closed.
descriptive matching does not isolate flipping from concurrent journal differences or establish uncertainty around the observed growth gap
Mean normalised IF and ARC also generally increased following the flip to an OA model, at a greater rate than was observed in the control groups.
the OAD results are equivocal and the descriptive design cannot attribute citation changes to conversion
However, the changes appear to vary largely by scientific discipline.
Table 2 directly shows materially different directions and magnitudes across four scientific fields and three outcomes
Overall, these results indicate that flipping to an OA publishing model can bring positive changes to a journal.
effect-like wording outruns a selected observational comparison with acknowledged uncontrolled determinants of journal success
Derived from the full evaluation — not a separate score.
Strengths
Each flipped journal is compared with a closed-access journal selected by discipline, publication volume, and IF in the flipping year. This improves on an uncontrolled before-and-after comparison.
↳ Data and methods, Control groups
Table 2 separates article volume, normalized IF, and ARC across Health, Social, Life, and Physical Sciences, revealing materially different trajectories rather than presenting only aggregate averages.
↳ Results, Variability between scientific fields; Table 2
The paper connects Unpaywall error to control-group construction, missing submission data to interpretation of publication growth, and publisher changes to visibility and author behavior.
↳ Limitations and Future work
Limitations
The Conclusion states that flipping can positively affect output and citations, but matching on three baseline characteristics does not isolate flipping from publisher, policy, APC, selection, or trajectory differences.
↳ Data and methods, Control groups; Conclusion
Figures 3–5 and Table 2 report means and growth rates without confidence intervals or inferential comparisons, limiting assessment of whether group differences exceed sampling or temporal variability.
↳ Results, Figures 3–5 and Table 2
The Abstract generalizes improvement in IF and ARC even though OAD ARC is stable, OAD IF growth is described as not exceeding interannual variability, and several field-level trends differ in direction.
↳ Abstract; Results, Article and journal level citation metrics; Table 2
The matched controls and two independently sourced journal groups make the analysis more informative than a simple uncontrolled pre-post study. Table 2 adds useful evidence that post-flip trajectories differ by field, while the detailed limitations section connects several data and selection issues to interpretation. The central constraint is that Figures 3–5 report descriptive averages and growth rates without uncertainty estimates or a design that isolates flipping from concurrent changes. Accordingly, the evidence supports differentiated post-flip trends more strongly than the Abstract and Conclusion’s effect-like claims.
Nabu’s assessment, alongside the field’s view.
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Confidence mediumThe control groups, second journal source, article-level citation measure, and field breakdown add incremental value. The principal directional findings remain close to Bautista-Puig et al. (2020) and the authors’ earlier work.
“We therefore attempt to address these limitations in the current study”
Matching on discipline, publication volume, and baseline IF improves the descriptive comparison, but no inferential analysis, pre-trend adjustment, or broader confounding control supports the effect-like conclusion. Selection and metadata limitations further constrain execution.
“we investigate the effect of flipping from CA to OA through a descriptive analysis”
The research questions, methods, results, figures, and table follow a coherent structure. The Abstract’s general claims about improved IF and ARC understate the stable OAD ARC, modest OAD IF change, and field heterogeneity.
“Mean normalised IF and ARC also generally increased”
The paper discusses the closest controlled study, conflicting citation evidence, and multiple sources of bias. Its limitations trace metadata, submissions, outliers, business models, and publisher changes to interpretation, although the concluding effect language remains somewhat stronger than this discussion warrants.
“More in-depth studies are needed to control for the various factors affecting journal success.”
Caveats4 of 4 checks
Reported values are internally consistent, but the strength of the overarching interpretation exceeds what the descriptive comparisons establish. The issue affects interpretation rather than the integrity of the underlying counts and metrics.
The study uses bibliometric metadata, identifies a public GitHub availability location for journal and control groups, and presents no evident ethics or conflict concern. Ethics approval and preregistration are not expected for this design.
Flags: 1 declared / 5 total
28 of 28 checkable references verified
36 references in manuscript 8 have no canonical index record — counted, but not index-checkable 1 reference confirmed by manual review
References not verified automatically are resolved manually within 24 hours.
No retraction or expression of concern found in Crossref (includes Retraction Watch).
Sources: Crossref (incl. Retraction Watch) ✓
Where this paper’s evidence sits on the path from initial observation to real-world use.
The analysis uses real journal outcomes, but remains retrospective and descriptive. It supplies preliminary decision evidence rather than validated implementation guidance or a cost-benefit framework.
“the results of our descriptive analysis”
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