Gold OA Citation Impact

• The paper demonstrates how methodologies such as FWCI, regression analyses, and interdisciplinary transfer metrics assess Gold OA's citation performance.
• Gold OA is a publishing model where articles are freely accessible upon publication, typically funded by APCs, enhancing dissemination and visibility.
• Empirical findings indicate citation advantages differ by discipline, journal rank, and funding, shaping how influence is measured in academia.

Gold Open Access (Gold OA) refers to scholarly articles published in fully open access journals, where the entire content is freely available to readers immediately upon publication. Typically, Gold OA involves Article Processing Charges (APCs) paid by authors or their institutions. The citation impact of Gold OA articles—the degree to which these articles are cited within the academic literature—is a critical indicator of their influence and dissemination. Extensive research has evaluated whether Gold OA confers a generalizable citation advantage, exploring diverse publication modalities, disciplinary variation, confounding factors such as funding and journal quality, and nuances such as interdisciplinary citation transfer.

1. Conceptual Foundations and Definitions

Gold OA distinguishes itself from other OA modalities (such as Green OA, hybrid OA, or Bronze OA) by virtue of the publisher providing free access to all articles in a journal, often facilitated by APCs. Within technical literature, distinction is maintained between (i) Gold OA in full OA journals, (ii) hybrid OA—where only some articles in a subscription journal are open, and (iii) repository self-archiving (Green OA). Gold OA may manifest as either pay-to-publish (most common), or diamond OA (no APC, typically subsidized).

The OA citation advantage hypothesis posits that articles available via open access receive more citations due to greater visibility, accessibility, and rapid dissemination compared with closed-access or paywalled articles (Dorta-Gonzalez et al., 2017, Dorta-González et al., 2017, Torres-Salinas et al., 2018). Metrics such as CNCI (Category Normalized Citation Impact), OACA (OA Citation Advantage), and field-weighted citation impact (FWCI) are commonly used for quantifying such effects.

2. Methodological Frameworks for Measuring Citation Impact

A variety of quantitative and comparative frameworks have been adopted to assess the citation impact of Gold OA articles:

• Article-Level Metrics: Most studies compute average or median citations per article, normalized to discipline and publication year, to account for differences in citation culture (Dorta-Gonzalez et al., 2017, Torres-Salinas et al., 2018). The OA Citation Advantage metric is formulated as

$$\text{OACA}_i = \frac{\text{OAC}_i - \text{NOAC}_i}{\text{NOAC}_i} \times 100$$

where $\text{OAC}_i$ and $\text{NOAC}_i$ are the mean citations for OA and non-OA articles in subject category $i$.

• Journal-Level Metrics: Indicators such as Journal Impact Factor (JIF), Scimago Journal Rank (SJR), and H-index are used to compare OA and non-OA journals at scale. Median tests and quartile analyses (Q1–Q4) offer robust comparison across non-normal distributions (Dorta-González et al., 2017).
• Field-Weighted Measures: FWCI is calculated as

$$\text{FWCI} = \frac{1}{N} \sum_{i=1}^{N} \frac{c_i}{e_i}$$

where $c_i$ is the citations received by article $i$ and $e_i$ is the expected citations for $i$ in its field (Cunningham et al., 15 Aug 2024).

• Decomposition of Citation Advantage: Recent research decomposes overall advantage into interdisciplinary (IOACA) and within-discipline (WOACA) citation components, elucidating knowledge transfer between domains (Nishikawa et al., 22 Nov 2024):

$$\text{IOACA}_i = \frac{\text{IOAC}_i - \text{INOAC}_i}{\text{INOAC}_i}, \quad \text{WOACA}_i = \frac{\text{WOAC}_i - \text{WNOAC}_i}{\text{WNOAC}_i}$$

• Regression and Correlative Approaches: Logistic regression, odds ratios, and Spearman correlation coefficients are used to control for confounding variables (e.g., journal rank, APCs, country income, international collaboration) (Momeni et al., 2022, Maddi et al., 2021, Maddi et al., 2022).

3. Empirical Results Across Disciplines and Modalities

Generalizability of Citation Advantage

Large-scale and longitudinal analyses indicate that Gold OA does not produce a universal citation advantage at either the article or journal level across disciplines (Dorta-Gonzalez et al., 2017, Dorta-González et al., 2017, Torres-Salinas et al., 2018). Citation impact is contingent on discipline, journal rank, country patterns, and publishing practices.

Modality	Citation Advantage	Notes
Gold OA (general)	Not universal; disadvantage	Most disciplines, except some medical
Hybrid Gold OA	Strong advantage (>2×)	Consistent across funding, fields
Green OA	Modest to strong advantage	Especially among unfunded works
Bronze, Delayed OA	Variable; context dependent	Aggregated with publisher OA

For example, analysis based on the Scopus and Web of Science databases found Gold OA journals typically have citation indicators lower or comparable to subscription journals, except for certain subject areas (Medicine, Multidisciplinary, and some Q4 quartile journals) (Dorta-González et al., 2017, Dorta-Gonzalez et al., 2017). In some cases, Gold OA articles show a median CNCI about 15% below the world average (CNCI ≈ 0.85) (Torres-Salinas et al., 2018).

Influence of Funding, Journal Rank, and Geographic Patterns

• Funding: Funded articles receive on average two to three times more citations in Gold OA journals than unfunded work, with an even larger boost to social attention metrics (Dorta-González et al., 2023, Dorta-González et al., 2022).
• Journal Rank and Quality: Higher journal rank (e.g., percentile H-index, JIF) is strongly correlated with both likelihood of Gold OA publication and higher citation rates (OR ≈ 1.98 for publication in higher-ranked Gold OA journals) (Momeni et al., 2022).
• Income-Level and Country Effects: Authors from high-income countries are overrepresented among highly cited Gold OA articles; in contrast, APC waivers increase Gold OA uptake among low-income countries but citation impact is less pronounced (Momeni et al., 2022, Torres-Salinas et al., 2018).

Article Processing Charges (APCs)

Contrary to widespread belief, paying higher APCs does not directly translate to higher citation impact. Correlation coefficients between APCs and impact score (NCS, MNIJ) are moderate (≈ 0.45–0.54) and largely explained by journal quality rather than APC level per se (Maddi et al., 2021, Maddi et al., 2022). Hybrid OA journals (with partial OA model) charge on average 50% higher APCs, yet tend to produce higher citation rates than fully Gold OA journals.

4. Interdisciplinary Knowledge Transfer

Recent work shows that Gold OA substantially increases interdisciplinary citations, especially in chemistry, computer science, and clinical medicine, where the overall OA advantage arises primarily via cross-field uptake rather than within-discipline citation (Nishikawa et al., 22 Nov 2024). Metrics such as IOACA highlight that, in certain fields, OA magnifies the propagation of results across disciplinary boundaries—a role distinct from just increasing total citation counts.

Journal-level analyses identified a handful of Gold OA journals (e.g., International Journal of Molecular Sciences, Journal of Statistical Software) as disproportionate contributors to high interdisciplinary impact in their fields, pointing to a heterogeneous effect among Gold OA venues (Nishikawa et al., 22 Nov 2024).

5. Practical Implications for Scholarly Communication and Evaluation

Gold OA supports enhanced dissemination—particularly to audiences outside the immediate research community. Notably, Gold OA articles exhibit a robust advantage in Wikipedia citation frequency; for example, their odds of being cited in Wikipedia are up to 64.7% greater than closed-access articles, controlling for citation count, journal quality, and time since publication (Yang et al., 2023). This confirms that OA accelerates public and scholarly communication.

From a research evaluation perspective, inclusion of Gold OA venues (including “grey” publishers formerly considered predatory) can distort normalized impact scores such as FWCI, since these venues may have fundamentally different citation landscapes and lower network centrality scores (e.g., MDPI, Hindawi, Frontiers <0.2 vs. Elsevier/ACM >0.2) (Cunningham et al., 15 Aug 2024). There is a strong impetus to supplement traditional citation metrics with network centrality, fractional authorship credit, and qualitative peer review markers.

6. Limitations, Controversies, and Directions for Future Research

The evidence for a generalizable Gold OA citation advantage remains inconclusive when controlling for discipline, journal quality, APCs, and funding. Observed advantages are frequently explained by selection bias, quality differential, and media amplification—OA articles more likely to be selected for cover features, media attention, and news outlet citation [0701101].

Limitations of current studies include field classification granularity, predominant focus on natural sciences, and lack of longitudinal control for confounders (field evolution, language, national journals). Comparative analysis with Green OA is essential, as repository-based dissemination (self-archiving) often yields comparable or superior citation gain at lower cost (0808.3296, Gargouri et al., 2010).

Future research should pursue:

• Deeper cross-modal analysis (Gold vs. Hybrid vs. Green) controlling for journal rank and author background.
• Temporal dynamics of OA citation effect at the article and journal level.
• Network-based citation quality weighting over absolute counts.
• Expansion into social sciences and humanities, with evaluation of altmetric and societal impact alongside citations.

7. Synthesis

Gold OA constitutes an essential modality for the democratization of scientific access, yet its citation impact is strongly modulated by discipline, journal rank, country-specific publishing culture, and funding. There is no evidence for a blanket citation advantage across research areas; instead, citation benefit is more likely for high-ranked journals and in contexts combining Gold OA with other favorable factors. Hybrid OA, Green OA, and well-funded Gold OA articles outperform paywalled or unfunded Gold OA articles in most studied contexts. The role of Gold OA in fostering interdisciplinary research transfer and public dissemination (notably via Wikipedia) is robust and supports the broader expectations for OA beyond traditional citation metrics. Evaluative frameworks for research impact must account for the heterogeneous landscape and methodological limitations outlined in the literature.