I've seen papers (e.g., in Science) where the first two authors are listed in non-alphabetical order, and yet there are asterisks behind their names to say that they contributed equally.

It seems strange to me, because if the two authors are in alphabetical order, then it could be that the first author contributed more or the two contributed equally, and this can be made clear with asterisks in the paper if it's the latter case. When they're in non-alphabetical order, however, if someone only sees the author list without seeing the paper, they will likely assume that the first author contributed most.

So my question is: Are there particular reasons why people do that? (This question is related, but I don't think the answers there get to my question.)

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    Maybe they flipped a coin?
    – user9646
    Commented Nov 28, 2015 at 21:04
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    No reason. It is their own right. Many people are not crazy about the author order. I have many collaborators (professors) who put me as the first author just for courtesy and I do the same in other joint papers. We assume that everyone has made an approximately equal contribution overall. Commented Nov 28, 2015 at 21:04
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    Related are the discussions in Uncommon order of author names Commented Nov 28, 2015 at 21:15
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    Given my last name, I have never been a fan of the Tyranny of the Alphabet over matters of equality, nor do I see any reason to perpetuate it. Commented Nov 29, 2015 at 22:57
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    If you really want to get ahead in academia, my advice is to legally change your name to Aaron Aaronson. Commented Nov 30, 2015 at 10:12

7 Answers 7


There are some requirements for funding¹², a degree³, tenure and similar for which literal first authorship counts. If one of the equally contributing authors gains an advantage from being the first author due to this while the other one doesn’t or has a smaller advantage, it can make sense to have the order deviate from the alphabetic one.

Another conceivable scenario would be that the first authors is well-known in the respective field and was made first author to attract a little bit more attention to the paper.

¹ For example several faculties in Germany have schemes for evaluation and publication-based funding that assign special value to first-author publications. Some of those do not mention joined first authorships and do not make sense with multiple first authors, which indicates that first authorship is meant literal (example in German, search for Erstautor).

² This journal, e.g., lists a handful of funding organisations that will pay the publication costs, if the first author is funded by the respective organisation. Joined first authorship is not mentioned. Even if this may be dealt with on a per-case basis, just flipping the first authors may be easier.

³ For example, for a publication-based PhD thesis, it may required that the included publications be first-author publications (example, again in German) without the case of joined first authors being considered. While the latter may be allowed on a per-case basis, flipping the authors may be much easier and avoid a lot of bureaucracy.

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    But surely the point of having the asterisks denoting the equal contributions is that there are multiple first authors. If one of the authors is in a situation (which I would like to hear more about) that they absolutely need sole first authorship, why not actually arrange for the reality to be that they contributed the most and make them sole first author? Commented Nov 28, 2015 at 21:53
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    @PeteL.Clark: I would not bet anything valuable on the assumption that there are no funding agencies or other elements of bureaucracy who interpret "first authorship" in the literal way - the author who appears at the first place of a list of authors (in which case the concept of multiple first authors does not exist). Commented Nov 28, 2015 at 22:34
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    In Japan for special visas for foreigners, only 1st publication counts immi-moj.go.jp/newimmiact_3/en (and unlisted -- only in scopus). Wouldn't surprise me if this (basically pointless) obsession with first extends to other features of the system here.
    – virmaior
    Commented Nov 29, 2015 at 10:31
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    To be honest, I see this "only the first first author counts" policy as a natural self-defence mechanism, given the current state of the authorship conventions. The policy "only the first author counts" is a response to author inflation in many fields. But if there is the possibility to add multiple first authors without any negative consequences, then its purpose is defeated. Then the evaluators and agencies say "only the first first author counts", to prevent first-author inflation. Then someone else invents "joint first first-authors"... Commented Nov 30, 2015 at 23:29
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    @virmaior Korea is the same, in my experience, no one actually looks at the paper, they look only at author name list, and take it literally. Any 'multiple first' is not taken seriously, because, of course, there still was someone first. Commented Dec 1, 2015 at 10:29

There are a couple reasons for doing this - most of which are rooted in the idea that the "first first" author still has an advantage. Some folks will still refer to the paper by "Adams et al." In fields where first authorship carries weight, some people "don't believe" in co-firsts. There's some ambiguity about whether a co-first author can put their name first on their own CV, which will be important for quick reads by people evaluating said CV.

Given that, there are a couple reasons:

  1. "Alphabetical ordering" inherently privileges one of the authors. They may, in the interest of fairness, "flip for it", or in a series of papers just alternate.
  2. "First first" might also be the one willing to field some of the post-writing effort behind a paper - actually submitting, fielding press inquiries, etc.
  3. There may be someone that benefits more. For example, a postdoc for whom this is a big deal publication may be put first so that they can reap any little residual benefit from those who don't pay attention to the note, instead of an established researcher who doesn't need it as much.
  4. Not all journals accept a co-first designation. So the order may be "If it comes down to it, and we can't share, it should be you" decision, even if it does make it into a co-first compatible journal.

One publication I'm on has a author order that involved 2-4.

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    "There's some ambiguity about whether a co-first author can put their name first on their own CV, which will be important for quick reads by people evaluating said CV." Wait, what? Some people believe that bibliographic information can be altered for their own benefit? I don't see any ambiguity there: that's a form of academic dishonesty. (Boy am I happy that I am in a field where author order is always alphabetical.) Commented Nov 29, 2015 at 5:49
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    @PeteL.Clark I've seen it advanced that way. If everyone is truly "Sharing First Author" and it's arbitrary, then everyone who counts as "co-first" should put themselves first on their own CV. I happen to disagree, but if you can't put your name first on your own CV, then "co-first authorship" really isn't.
    – Fomite
    Commented Nov 29, 2015 at 5:51
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    @PeteL.Clark The dispute is what the "truth" is for fields where there isn't a clear ordering system. You're also arguing with me like this is a position I actually hold.
    – Fomite
    Commented Nov 29, 2015 at 5:58
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    @PeteL.Clark And if the truth is that you and your co-author truly both "first authored" the paper (given that has a meaning in the field), then why is it that Aaron Aaronson's name is always first? If its arbitrary, it's arbitrary. Like I said, I don't necessarily hold that position (I think co-first is a silly attempt to address a genuine issue), but it's not insane. And it is a reason for the reasons I listed above.
    – Fomite
    Commented Nov 29, 2015 at 6:01
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    @PeteL.Clark: "what is being said is that Aaron and Zed are equal, but if you really care then Zed is a little more equal than Aaron" - actually, I don't think that conclusion is valid. What is being said is that Aaron and Zed contributed equally, but that Zed is more relevant in the current context (e.g. Zed's CV). I do not agree with the practice, but only because the common assumption leans towards an unambiguous ordering (which I consider one of many relics from the times of printed publications) and thus staying true to the semantics by switching the order of equal authors might confuse. Commented Nov 29, 2015 at 14:27

Two authors who regularly collaborate may have a rotation scheme going (with footnotes about equal contribution). That is, they take it in turns to be first author on any of the papers that is about their joint research. This avoids building up a substantial difference in first authorship, which can be important on CVs where the footnotes are not visible.


Many factors may affect order in a list of authors. And this is field-dependent. In mathematics, one usually considers that all authors contributed equally, and use the alphabet order.

In addition to @Wrzlprmft, one may for instance ask whether Do age and professional rank influence the order of authorship in scientific publications? Some evidence from a micro-level perspective.

I have experienced three other cases, with globally equal contributions between authors. "Globally equal" is a very complicated concept, illustrated thereafter.

In an overview four-author paper (A panorama on multiscale geometric representations, intertwining spatial, directional and frequency selectivity), we (the three other authors) decided to put as "first author" the one who had not a permanent position at the time of submission, and who did a great job in gathering article pieces and assembling contributions. In a five-author paper (CHOPtrey: contextual online polynomial extrapolation for enhanced multi-core co-simulation of complex systems), the first one was the (sole) woman author, and the youngest. This concept took us about 5 years to develop, with people moving in and out, and she did the final programming. And last, we swapped places in a two-author paper (Lapped transforms and hidden Markov models for seismic data filtering), because the alphabetical order put a too-heavy birth advantage on one of us.

All because of this "silly" thinking that the first author did more work, and since in some disciplines (biology, medicine), the citations are often in the shape "Author 1 et al., Year, Journal". And sometimes there is a strange feeling that, in order or importance, there is some hidden hierarchy like:

  • first author
  • last author
  • second author
  • penultimate or second-to-last author
  • third author
  • while other authors could be straw people.

So, my three rules of bibliometrics:

  1. authors' list should be agreed on among authors (sounds odd, but sometimes one guy really does not belong),
  2. authors should agree on an order,
  3. for the rest, do not let bibliometrics rule the above. Scientific integrity and honesty should prevail.

Linked stories:

  • But if you say that the asterisked authors contributed equally and then you list them out of alphabetical order, aren't you simply contradicting yourself? (Or perhaps you are a fan of Animal Farm: "All animals are equal, but some animals are more equal than others.") If you really think that a statement that authors contributed equally will not be believed and/or will be at the expense of one of the authors, why not actually arrange for the first listed author to contribute more and dispense with the asterisks altogether? Commented Nov 28, 2015 at 21:51
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    There is a gap between what authors mean, and what people read. Some never read footnotes (and asterisks), as many insurance companies know. The authors may wish a specific order, and the journal may impose a note on relative contribution. The contradiction, to me, lies in scientific evaluation based on order, notes or impact factor. Commented Nov 28, 2015 at 22:00
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    Every word or typographic sign in a paper can be interpreted by some, ignored by others. I never had to use asterisks before in my field (equal contributions assumed, the student often put first), until a recent paper in Bioinformatics, where we were obliged to do so, at the very end on the publishing process. I do not like nor try to defend this concept. I do care about your lack of integrity concern. I only share a witness observation on the many different practices in different areas of science. Commented Nov 28, 2015 at 22:13
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    A follow-up on some of your concerns: I do work in signal and image processing. Some worthy young applying candidates from mathematics are disavantaged because of the poor knowledge of people in the neighboring field, and the first letter of their names, at the end of the alphabet. That is why these discussion are important, to fathom the different uses in science Commented Nov 29, 2015 at 7:42
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    Could you please share some details about the third story - adding author in R&R? What's wrong with this practice? Any blogs or news that covers that story? Any related information will help. Thanks in advance.
    – High GPA
    Commented Dec 1, 2021 at 2:18

In Brazil, the order of authors defines fellowships and fundings. There are some fellowships that you cannot apply for if you don't have at least 2 publications as first author.

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    What fellowships?
    – sourcream
    Commented Mar 29 at 14:07

At the Collaborative Institutional Training Initiative, there is an interesting article on "Authorship" by Stephanie J. Bird, which basically boils down to the fact that practices are completely variable on the issue between different disciplines:

The significance of the order of authorship is also variable within fields and sub-fields. Again, universal, definite rules for author order are generally lacking. The order may reflect the extent or nature of one's contributions, for example, who did the "most" work, who had the primary or key idea, or who wrote the first draft of the manuscript. Historically, the head of the research team, normally the most senior researcher, was listed first. This practice is still somewhat common but more recently, that individual may be listed last, especially in the life sciences.

In some physical sciences, particularly experimental physics, authorship is typically alphabetical. An alphabetical listing is also used by some journals, and in some research groups, alphabetical (or a version of it) may be standard practice. For example, contributions may be listed alphabetically except for the head of the research group who is listed first or last. When a research team produces several related papers derived from the same project, the order of authors may rotate.

... In many fields, the first author is the individual who earns the most credit by having taken primary responsibility for the intellectual core of the work. (On occasion, the last author is primarily responsible for the work's intellectual core.) This individual may also be known as the "lead" or "primary" author. This convention has developed in part because of the practice of referencing relevant, related work in the literature by the last name of the first author followed by "et al." when there are more than two or three authors depending on the journal. Thus, while a paper by Sandra Dunn and Jonathan Thomas would be cited as "Dunn and Thomas", a paper authored by Sandra Dunn and three other individuals would be cited as "Dunn et al."

... In spite of the emphasis and attention paid to author order and the designation of corresponding author, the actual significance of any particular order of authors can be opaque and open to misunderstanding and misinterpretation. A reader's assumptions may not be consistent with the assumptions and intentions of the authors themselves. The recognition of individual authors is most likely to reflect their reputations, the reliability of their work, the reputation of the colleagues with whom they choose to work and of their trainees, and their cumulative contributions to the field.

Because of the complexities with determining what a particular author list means, some journals use an asterisk, or another similar strategy, attached to each author's name as a means for more specifically spelling out the relevant person's specific contribution to a project. At times, it can be used to indicate that the authors contributed equally to the work either as co-first authors or as corresponding authors.

A sampling of Bird's references that seem on-topic:

  • Claxton, Larry D. 2005. "Scientific Authorship: Part 2. History, Recurring Issues, Practices, and Guidelines." Mutation Research 589(1):31-45.
  • Bebeau, Muriel J., and Verna Monson. 2011. "Authorship and Publication Practices in the Social Sciences: Historical Reflections on Current Practices." Science and Engineering Ethics 17(2):365-88.
  • Borenstein, Jason. 2011. "Responsible Authorship in Engineering Fields: An Overview of Current Ethical Challenges." Science and Engineering Ethics 17(2):355-64.
  • Macrina, Francis L. 2011. "Teaching Authorship and Publication Practices in the Biomedical and Life Sciences." Science and Engineering Ethics 17(2):341-54.
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    Can you modify your answer such that it addresses the question more directly?
    – Wrzlprmft
    Commented Nov 29, 2015 at 10:51
  • "In some physical sciences, particularly experimental physics, authorship is typically alphabetical." - this statement is clearly, obviously false and thus indicates that the whole "work" by Ms. Bird is highly questionable. Of course, no offense to the user who gave this answer; they might not know this.
    – sleepy
    Commented Apr 27, 2021 at 17:18

I do not know if Science has a convention for this, but let me tell you about the convention in Economics and Finance journals. The most common way to reference articles is to cite by authors-date and in alphabetical order, for instance: Kahneman and Tversky (1979). In Economics or Finance, the order of the authors does not usually indicate any seniority or importance in the contributions.

If the non-alphabetical order of authorship indicated anything, the authors would usually explain it in a footnote. For instance, I have seen authors indicate that the order reflected the winner of a particular game of chess, but I do not recall which article it was.

Authors who publish quite a bit together occasionally swap the order of the authors, e.g. Tversky and Kahneman (1991). This can be done for a variety of reasons and it is up to the authors to decide to do that. The journals would not (as far as I know) make any such request. A common reason for non-alphabetical listing of authors is that the authors have two papers published together in the same year and they find it clearer to use the reference style Tversky and Kahneman (1991) rather than Kahneman and Tversky (1991b).

Examples of References:

Kahneman, Daniel & Tversky, Amos, 1979. "Prospect Theory: An Analysis of Decision under Risk," Econometrica, Econometric Society, vol. 47(2), pages 263-91, March.

Tversky, Amos, and Daniel Kahneman. 1991. "Loss Aversion in Riskless Choice: A Reference-dependent Model". The Quarterly Journal of Economics 106 (4). Oxford University Press: 1039–61.

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