You identify a crucial issue in contemporary academia. Fraud!

It is not possible for 20 people to contribute to a paper, although four or five might.

The integrity of academia is at stake.

Authors must make a "substantive contribution" to the conception and writing of the article, or they can receive an acknowledgement in the footnotes.

Douglas - this is an issue. I remember responding to a similar post several months ago whereby a paper had hundreds of authors (it might have been more). Of course, you have to question how the publishing industry allows it (unless it's predatory journals). After all - think of the copy space it takes up!!

I do believe that it is cultural. In a 'publish or perish' space it's about helping out those 'you know' rather than those you work with perhaps. If everyone does this reciprocally, then it's 'you scratch my back and I will scratch yours'.

That said, how credible is the 99th author of 100 (assuming that the hundreth author is the 'consultant' author) in the eyes of the academic community? It's where publishing just becomes a 'game'.

You identify 20 - which is starting to push the boundaries - but might be legitimate with a large, international cohort study team for example - especially if it is acknowledging research assistants, data analysts etc.

I take on board Halford's point about academic 'fraud' - but until it is 'officially' promoted as fraud (if that will ever be the case) - then the practice will remain.

Physics paper sets record with more than 5,000 authors

Detector teams at the Large Hadron Collider collaborated for a more precise estimate of the size of the Higgs boson.

There can be multiple authors, if required.

However, in some cases just unnecessary increase of authorship.

You will find the details of the physics paper in the internet.

In my own subject I saw a paper of about 100 authors but everyone deserve to be the author of that paper.

Well it depends on the area of study and type of research question being addressed. These days in the large scale multidisciplinary studies (specially Physics papers) we can see a lot of contributing authors. Kindly refer the enclosed image.

I agree with Halford H. Fairchild and Dean Whitehead . Academic integrity in such cases is questionable.I imagine that a 'scratch my back, scratch yours' attitude is at play here, which is quite shameful and could possibly amount to fraud. while 'collaborative' research is very much encouraged, there should be a certain limit to the number of authors per article e.g. five. On top of that, an indication of individual contributions to an article should be submitted to the journal editors as a condition for acceptance.

I think that practices and the accepted meaning of "authorship" does vary between disciplines. I too struggle to imagine how something like the paper shown by Sunil Kumar Sahu - could have 2300+ authors in any sense that I understand the word - that's probably one word each!

While not always observed, in he field of medical / health there has been a strong move toward making this a key issue of publication ethics with more or less accepted criteria for what defines authorship as opposed to a 'contribution'. The international committee of medical journal editors gives a recommendation that is accepted by many journals: authorship should be based on the following 4 criteria:

• Substantial contributions to the conception or design of the work; or the acquisition, analysis, or interpretation of data for the work; AND
• Drafting the work or revising it critically for important intellectual content; AND
• Final approval of the version to be published; AND
• 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

( http://www.icmje.org/recommendations/browse/roles-and-responsibilities/defining-the-role-of-authors-and-contributors.html )

This may not work for all disciplines but it is, I think a start. There is a need for senior academics to role model good behaviour and put an end to the expectation that minimal involvement and contribution merits authorship as some sort of right, simply because of association. The flip side of this is that many who have made substantial contributions do not get mentioned at all!

For this matter, institutions and regulatory bodies should come forward to discourage this practice of having XX...nX authors in a single paper (Probably a result of scratching each others back as Dean Whitehead mentioned).

For recognition and promotion in academia there should be limit to authorship number in the paper. For example a paper in which a person is 6th or higher number will not be counted/considered for promotion.

This is not a difficult decision to take and implement for controlling this "academic fraud".

That is a very correct and real observation sir. I think the selection of co authors is mainly about the contributions of the different individuals (the first 3 in most cases), the rest of them appear in the list as favours, obligations (laboratory or course mates), science celebrities (who for the most part don't even know anything about the work), family members (who might not even really be scientists), etc

nevertheless, I don't find single/few author papers to be interesting and real

This practice is growing and I was once requested by a professor to put someones name in my paper who was not even a part of that project. I refused and told him it is unethical. That day I really felt why and how they even can think like that.. What about our moral principles?

If authors are more than 3-5 in a research paper. It means an academic froud is going on in the academia. As reviewer of 51 International SCI journals of very high impact, I have observed that a good publication may have 3 to 5 contributers in maximum. It is the duty of reviewers to rejects immediatly such kind of nexus work.

I agree with the views expressed here. Really it is even complex to arrive at a meaningful contribution in consensus if too many authors are involved (Assuming all are contributing). However, for some studies which requires to collate the findings from multiple countries (for example, research on some tropical diseases), it is justified. But, I suppose, maximum 4 authors should be allowed in a typical social science or Management Research and all journals must include the clause for the contributors to state how individually the authors have contributed. It is not always true that only first and second authors are contributing and third author or fourth author is just an inclusion.

In this context I am tempted to ask a question:

How an editor or an interviewer perceives the author's contribution (unless mentioned explicitly in the paper) whose name is appearing at first, second, third and fourth position respectively.