Individuals listed as authors must satisfy all 4 criteria of authorship by the ICMJE: “1) Substantial contributions to the conception or design of the work; or the acquisition, analysis, or interpretation of data for the work; 2) Drafting the work or revising it critically for important intellectual content; 3) Final approval of the version to be published; and 4) Agreement to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved” (1).

Inappropriate assignment includes gift (‘honorary’ or ‘guest’), ghost, swapping, and theft authorship (2). Gift authors are those who do not contribute to the works. Gift, authors are usually supervisors, chairs, or senior researchers who can be acknowledged for their non-scientific contributions and moral support. Most of them meet the contributorship criteria defined by the ICMJE but some of them are real guests without contribution. Ghost authors are those with substantive contributions with apparent conflicts of interest, usually affiliated to pharmaceutical agencies, who deceive the readers by omitting their names from the author bylines. Swapping authorship is an act of exchanging ‘gifts’ by mutual agreements. And theft authorship is an act of misappropriation of others' works. Of all these unethical assignments, gift authorship is perhaps the commonest in Korea.

Gift authors agree to be listed in the bylines to advance their academic career and successfully compete for research grants. Serial violations of the authorship norms affect research environment and coincide with other ethical transgressions (3).

Unethical authors may argue that the authorship is a matter of collegiate agreement between contributors and journal editors should not be concerned. Some of the gift authors may even believe that they deserve authorship credits to honor their administrative duties and ranks. But they also should care about academic honesty and respect norms established by the editors' community.

The journal editors encourage their contributors transparently disclose all scientific, technical, administrative, and financial contributions and be prepared to take responsibility for all parts of the scholarly works bearing their names as authors. Gift authorship is deceptive toward readers who sincerely believe that all listed authors are professionals impacting science and introducing rational ideas. Also, long author bylines can dilute academic credits, entirely belonging to the first authors and deserving exclusive records in their biographic notes. The diminished role biographic notes and inflated research productivity metrics negatively affect the whole system of academic promotion, relying on individual publication activity and citations.

I have analyzed number of authors listed in the Journal Korean of Medical Science (JKMS), Yonsei Medical Journal (YMJ), and JAMA during 1990–2015. The results are presented in Table 1. Annually, number of authors increased from 3–4 in 1990 to 6–7 in 2015 in all 3 general medical journals. The trend can be explained by growing number of researchers, collaborators, and centers involved in research worldwide. The increasing number of authors was more noticeable in original articles than in case reports of the JKMS and YMJ. There was no change in number of authors of case reports in the JAMA during 1990–2015. Analyzing number of authors per original article for single institute during 2000–2015, figures were 6–7 in the JKMA and YMJ, and only 2.2 in the JAMA in 2015 (Table 1). Suspicion raises as to whether this trend of multi-authorship in Korean journals is due to gift authorship.

When I ask some corresponding authors to reflect on contents of their manuscripts submitted to the JKMS, they surprise me by unawareness of what is in their works and that they have to be accountable for their articles. On numerous occasions, the first authors respond to the queries of the editorial staff instead of the corresponding authors. It clearly points to inappropriate (gift) corresponding authorship that requires related revisions in the editorial policy of the journal.

The Korean society has a tradition of Confucianism, which is essential for preserving humanistic values in the country. The same culture, however, may confound inappropriate (gift) authorship and lead to violations of the norms of publication ethics acceptable for the global scientific community. Korean researchers should be aware of the global standards of research and publication ethics and adjust their authorship assignments accordingly.