Beyond Predatory Publishing: Additional Questionable Offers in Scholarly Publishing

Besides predatory publishing, there are other practices in the area of scholarly publishing which are not about advancing science, but rather primarily intended to increase the authors’ output or impact in return for financial compensation. David Bimler terms this “publication facilitation”, which also includes dubious or hijacked journals because they offer dishonest researchers an opportunity to publish questionable results [Bimler 2022], but primarily refers to the sale of finished manuscripts and other services (see also the article by Andreas Ferus and Gerlinde Maxl in this blog:

Paper Mills – selling authorship and author positions as a business model

Anna Abalkina, a researcher at Freie Universität Berlin, defines paper mills as follows: “Paper mills are commercial companies that organize on-demand writing of fraudulent academic manuscripts and offer co-authorship of these papers for sale” [Albakina 2023]. In addition to writing manuscripts and selling author positions, further services are offered as a kind of “full service” [Dirnagl 2022]. This includes, for example, the full support during the publication process from manuscript submission and peer review process to revision and indexing. The cost of using the service(s) depends on the journal’s impact factor and the specific author position, with first authorship position being the most expensive [e.g. COPE & STM 2022].

These manuscripts for sale contain manipulated or invented data and figures as well as plagiarized text passages. It can be assumed that software is used to conceal obvious acts of plagiarism. This is indicated by so-called “tortured phrases”, i.e. phrases that are used instead of correct professional terminology (e.g. “colossal information” instead of “big data”) and presumably originating from translation software [Else 2021]. Most likely, the reason is probably that publications from non-English-language journals are translated and assigned new author names [Dirnagl 2022].

Articles with available author positions are offered for sale via websites, social media pages or chat forums [e.g. Else 2023]. As a result, there is an accumulation of author names associated with the articles that makes one wonder how these people came to cooperate, since there are neither spatial nor subject-related overlaps. This, on the other hand, may also be used to identify the publications in question [Albakina 2023]. It is also possible that legitimate authors sell co-authorships for their already accepted manuscripts via the paper mill, i.e. the paper mill only acts as an intermediary [Albakina 2023]. The system attracts free riders, too: author positions for articles with a forged “letter of acceptance” are also likely to be sold via social media channels [Neumann 2023].

The purchasers’ names are added during the peer review process [Else 2023], usually after the first round of reviews and before the final version of the manuscript is submitted.

The central point is the “placing” of the manuscript in a journal. Several strategies are applied during the submission process to maximize the likelihood of acceptance:

  • Manipulation of the peer review process: many journals allow authors to suggest reviewers. While editors are not obliged to follow the suggestions, they might see this as a way to make their work easier and are happy to make use of them. A peer review request can then be forwarded to the paper mill by means of fake email addresses, which will then submit a positive review [COPE & STM 2022].
  • “Control” or even assignment of editors by the paper mill itself, for example in the context of special issues, for which journals often rely on external editors [e.g. Oransky 2021]; Albakina 2023]. This ensures that decisions made by the editorial board are in favor of the articles submitted by the paper mill [Bishop 2023]. Furthermore, names of researchers working in the field may be used. The email addresses used, however, are made up so that all messages are sent to the paper mill [Oransky 2021].
  • Simultaneous submission to multiple journals to increase the likelihood of acceptance [Else 2022]; if the paper gets accepted by one journal, the other submissions are dropped [COPE & STM 2022].

“Citation trading” and “citation circles” – dishonestly increasing impact through irrelevant citations

Citation cartels – i.e. citing each other’s publications as a favor – have been known for some time, as have requests of some journal editors to their authors to kindly include more references to publications in their own journals. “Citation trading” or “citation circles” (groups of authors who cite each other, but whose work is actually not related) however, involves monetary gain [Bimler 2022]. In order to minimize the risk of discovery, additional passages are added to an article once the peer review process has been completed –  i.e. during the revision and correction phase – in which corresponding works from the “pool” or “circle” are cited regardless of the context [Neumann 2022].

Occasionally, questionable publishers also offer “cash for citations” if authors place references to the publisher’s journals in their already accepted manuscripts – preferably in journals that are listed in Web of Science. The amount earned depends on the number of articles cited [Marcus 2021].

Manipulating CrossRef metadata is another alternative. This means that additional references are inserted into the corresponding CrossRef field that are not included in the HTML and/or PDF version of an article. Since this field is used by certain services such as Dimensions ( to count citations, it can be used to artificially inflate impact numbers. The question remains as to whether or not there is a business model behind this strategic approach. Nevertheless, one must remain skeptical towards very large discrepancies in the number of citations on different platforms [Singh Chawla 2023].

“Combined offers”

Frequently, several services are offered in combination: not only is authorship of publications offered for sale, but also citation of these publications is ensured. A clear distinction and systematization of these questionable activities is therefore difficult [Bimler 2022]. Studies usually tend to focus on individual paper mills, which in turn can quickly adapt their “business model” in order to respond to “market needs”, such as trend topics in the acquisition of third-party funding, but also to the increasing awareness within the scientific community [Albakina 2023; Bimler 2022].

What is astonishing is the casual way with which the “services” are offered – and the euphemism used. Scientific misconduct is sold as a “publication service”; contracts in which both parties agree to confidentiality are signed. Even reimbursement is provided if the “publication efforts” are not successful. Furthermore, customers are also supported if a retraction of the article becomes unavoidable [COPE & STM 2022].


All of the developments described above constitute scientific misconduct, as publications with falsified data, plagiarism, false authorship, manipulation of the peer review process and citation without reference to the line of argumentation no longer have anything to do with scientific integrity. As a result, publications ought to be withdrawn as soon as they are discovered. Accordingly, “massive retractions” have been repeatedly observed since 2020 [e.g. Albakina 2023]. In addition, multidisciplinary citation databases such as Web of Science are also responding and suspending the indexing of journals that have been massively compromised or manipulated. This also means that these journals are no longer assigned a journal impact factor for the time being [Kincaid 2023].

What is worrying, however, is that these publications are veritably “cluttering up” the scientific state of the art until they are discovered, making it increasingly difficult to filter out valid results. As a consequence, the publications circulated by paper mills can also distort evidence syntheses or reviews [Dirnagl 2022] which are used as a reference for deriving treatment methods for patients or for policy measures. As a result, not only the scientific community but also society at large lose out.

Scope of the problem and application of technical means of countermeasures

It is difficult to estimate the extent of the problem. First estimates based on analyses with software that has been specially trained to recognize publications from paper mills assume that 1.5-2% of the publication volume in 2022 may be attributed to paper mills – in biology and medicine even 3%. In absolute numbers, this amounts to 70,000 publications in 2022 or an estimated 400,000 publications over the last 20 years [van Noorden 2023]. Almost all major publishers are affected, including journals from learned societies – albeit to a lesser extent [Bimler 2022]. As mentioned above, special issues of journals are a popular venue for submissions. Collaboration with hijacked or predatory journals (either intentionally or unintentionally) is also conceivable, as these represent an easy way for paper mills to place their articles [Albakina 2023; Perron et al 2023].

As part of the STM Integrity Hub (, publishers are now joining forces to tackle the problem. Submissions are screened with the help of tools and searched for criteria such as image manipulation that indicate a paper-mill production. The complete list of criteria remains confidential to prevent paper mills from making adjustments [van Noorden 2023]. This much is known: paper mills work according to the principle of “maximizing profits fast” and therefore act as efficiently as possible: once content, references or even peer review reports have been created, they are “reused” [Bimler 2022] or templates are used [e.g. Bimler 2023; van Noorden 2023; Christopher 2021]. This results in patterns that can be used for automated detection.

Another criterion to look for are multiple submissions, as paper mills often submit to multiple journals at the same time to increase their chances of (rapid) acceptance [Else 2022].

Yet another approach involves searching a paper mill’s website (or snapshots of it on platforms that archive websites) for article titles available for purchase. The titles mentioned can then be used to determine if and where the articles are subsequently published [Perron et al 2023].

Raising awareness on different levels

In general, raising awareness is essential to detect and retract questionable publications more quickly and prevent false findings from being used or evaluated as part of a review [Candal-Pedreira 2022]. It is also important in this context that the publications concerned are not cited, which in turn presupposes that it has been recognized that these publications do not reflect the state of the art. Although many of the articles are not cited, some may still have a considerable number of citations [Teixeira da Silva & Nazarovets 2023], although these may also originate from the paper mill itself [Albakina 2023]. In addition, since retracted publications tend to not be deleted, the impact generated by them with rather meaningless references remains permanent for the cited publications [Bishop 2023].

Ideally, paper mill articles would not even be published in the first place – this requires the use of the tools described above, as well as the education of editors and reviewers [Else 2022]. In general, journals have a particular responsibility because they disseminate scientific results [Christopher 2021]. An adaptation of workflows and “author guidelines” by the journals, e.g. an obligation to use institutional email addresses and listing the contributions of the individual authors to the manuscript or, in addition, the co-supervision of special issues by members of the core editorial board could also make the work more difficult for paper mills [Perron et al 2023].

Current practices of research evaluation as a cause

A supply market only ever emerges in response to a demand. Similar to predatory publishing, these services only respond to the researchers’ eagerness to comply with the evaluation policies to which they are subject – a behavior that to a certain extent ensures their advancement in the scientific community (see also the article by Susanne Luger in this blog: The recommendations in the COPE & STM Report [2022] therefore advise research institutions and funders, among others, to rethink their research evaluation practices accordingly. Thus, in addition to “closing down” questionable business operations, retracting their publications and therefore sending a signal that they are not state-of-the-art, another starting point for combating questionable practices is to reform the current evaluation practices, which are based on quantitative indicators of output and impact. Initiatives such as CoARA with the “Agreement on Reforming Research Assessment” ( therefore propose to move away from solely quantitative indicators in the assessment of research performance and include more qualitative assessment practices such as peer review instead.


Abalkina, Anna (2023): Publication and collaboration anomalies in academic papers originating from a paper mill. Evidence from a Russia‐based paper mill. In: Learned Publishing 36 (4), S. 689–702.

Bimler, David (2022): Better Living through Coordination Chemistry. A descriptive study of a prolific papermill that combines crystallography and medicine. Preprint.

Bishop, Dorothy Vera Margaret (2023): Red flags for paper mills need to go beyond the level of individual articles. A case study of Hindawi special issues. Preprint.

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