In my field (theoretic CS) it is very common to list the authors names alphabetically on papers.

I have been working on a paper for quite a long time with three other researchers, which is almost complete, and in the last week or so we consulted another researcher who made a non-negligible contribution to the paper by pointing out (with a proof he thought of after considering the problem with us for a couple of days) some direction we were working on shouldn't work and suggesting considering a different direction - the final version of the paper will not include his ideas but we probably wouldn't finish it on time without realizing we are following a dead-end.

So, he deserves being listed as an author if he wishes, but the problem is that if we list the names alphabetically his name will be first - is it acceptable to put our three names (alphabetically ordered) before his, breaking the common alphabetical order? If not, what is the usual practice in such cases?


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    In theoretical CS (as is in math) all authors are equal. You suggest that some should be more equal than others :-) Generally, it is better to be nice and offer coauthorship. You lose rather little doing so.
    – Boris Bukh
    Commented Jun 7, 2015 at 16:04
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    If your final paper doesn't include his ideas of his work, why not just include him in the acknowledgements and/or give him a citation boost by citing some of his papers?
    – RoboKaren
    Commented Jun 7, 2015 at 16:11
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    @RoboKaren Is it appropriate to cite people in your paper as a way of saying "thank you"? Personally, I don't like the idea that the content of an article should include tit-for-tat favors.
    – Sverre
    Commented Jun 7, 2015 at 18:25
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    Presumably the other author's contribution came from somewhere in their speciality -- thus "The authors would like to thank Jane Roe for her insights on combinatorial matrixes which contributed considerably to the argument of this paper. Her suggestions build from her work in folding proteins (Roe 2014, 2015ab)."
    – RoboKaren
    Commented Jun 7, 2015 at 20:11
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    I agree with @Sverre: citations should be directly relevant to the work, not influenced by other considerations. In contrast, the acknowledgments section should not contain academic content that is not mirrored elsewhere in the paper. Thus including citations only as acknowledgments would look strange. Moreover, many people have expertise far removed from their publication list. I would say that at least half of the things I'm acknowledged for in papers would not reasonably correspond to any citation to my own work. Commented Jun 7, 2015 at 20:19

3 Answers 3


In fields (like pure math and TCS) in which the convention is to list authors in alphabetical order, it makes a very jarring, striking statement to put authors non-alphabetically. The most common instance of this in my experience is when one author is very senior, enough to perform a power play on their very junior coauthor. Unless the reasons for the non-alphabetical order are carefully explained and seem logical to the readers, this could make a widely negative impression.

Non-alphabetical ordering is almost never used in pure math and TCS to signal importance of contribution: the convention, for better and for worse, is that the authorial contributions are not disclosed to the reader. As a result of this, unlike many other academic fields in which being a fifth author may be understood to mean very little contribution, in pure math and TCS there is a cutoff phenomenon: you have to decide what level of contribution merits coauthorship, and there will certainly be many cases in which a positive contribution does not result in an authorship. People who are not coauthors but made intellectual contributions to the work should be acknowledged for this. If you read acknowledgments on papers in this area, you will find that people are sometimes acknowledged for things that are clearly significant contributions: e.g. for providing the key idea of the project, or for providing correct proofs of key technical results needed by the authors.

The general conventions are to be generous and modest. Namely, the coauthors should err on the side of generously offering coauthorship to those whose contributions were positive, even if they were lesser in magnitude than the other coauthors. On the other hand, one should be modest in responding to coauthorship requests: if what you did feels like helping out a colleague rather than doing substantial, original work, then probably you do not want to be listed as a coauthor.

Of course in practice there is a lot of subjectivity here. In the case at hand, another answerer says that because your colleague's contributions "did not actually make it into your paper", then they are not sufficient for coauthorship. I don't completely agree. Telling people what not to do and setting them back on the right track can be an invaluable contribution.

Recently a junior colleague found a key mistake in a draft of a work of mine in which she was not an author. The coauthor and I withdrew the paper immediately and were able to fairly quickly recover the main result of the paper by arguing in a different way. The paper was then accepted. I think it is quite likely that if not for my colleague's contribution, the original, erroneous version of the paper would have been published. In principle we would have fixed it eventually, but in practice: yikes -- she deflected a bullet. I offered my colleague coauthorship...and she declined. In this case the offer was essentially mandatory, whereas both accepting and declining it seem reasonable.

If the OP feels that the contribution to the work was sufficient to make it plausible for the contributor to be listed as an author, I would recommend that the coauthorship offer be extended. If you know your colleague pretty well, I might follow the offer with an offer to discuss the situation: that's a good way to make sure that you reach an outcome which you are both comfortable with. I don't think your colleague's last name has any role to play in this discussion.

Added: Here is the American Mathematical Society's 2004 "culture statement" on coauthorship. It says that more than 75% of coauthored math papers with at least one American author use alphabetical order, and that this percentage is over 90% in pure mathematics. I think that for publications in more mainstream and prestigious journals, the percentage is even higher. For instance, I checked the last 100 multiply authored papers in the Journal of the American Mathematical Society and found that alphabetical order was preserved 99 out of 100 times.

The cultural statement also says: "Joint work in mathematics almost always involves a small number of researchers contributing equally to a research project." Unfortunately I do not completely agree with this statement. For one thing, the number of coauthors on papers has been rising so sharply that even a statement from 2004 seems a little out of date: I remember that 10 years ago, seeing a math paper with more than three or four authors was worth a raised eyebrow. That is really not true anymore: a substantial minority of papers has a long enough list of authors -- with such widely varying expertise -- that it is not plausible that all are contributing equally. Moreover, unlike alphabetical order, I don't know how one can gather statistics about whether authors contribute equally. To me this statement reads like an aspiration rather than a description of reality. In my experience, there is a cultural push for authors to contribute equally, but there are other cultural pushes as well. Listing authors alphabetically essentially always in confluence with the reality that sometimes the contributions are not equal seems to me to an underacknowledged problem of our profession.

  • I'd like to disagree with the statement that non-alphabetical ordering is almost never used, seems to indicate a powerplay, and produces a negative impression. This may be true for some areas of pure math, but it is certainly not true for all of math (see my own perspective in another answer). Commented Jun 7, 2015 at 21:18
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    @Wolfgang: I agree that I should have restricted to pure math. We can try to scope it more precisely, but in every part of pure math that I know about, non-alphabetical order indeed is almost never used and the use of it would be regarded by many as a social error. Commented Jun 7, 2015 at 21:33
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    Agreeing with this answer ... and especially the completely civil offer-and-declining of co-authorship anecdote as decent, sensible behavior. The idea from AMS that it is possible to appraise "equal contributions" is hilariously silly to me, at best. For unequal contributions, according to the soon-to-be-seen AMS gauge, perhaps we can use different font sizes for the authors' names. All this comes back again to the pathetic situation that so many (especially young) academics are pressured by administrations to worry about "getting maximum credit"... Keeping status-point score, psh! Commented Jun 7, 2015 at 22:08
  • @paul: Are we reading the same AMS statement? It simply points out that most multi-author pure math papers list authors alphabetically, thus presenting them as having contributed equally. Of course it may not really be true that their contributions were equal; there may not even really be any way to compare them. But the point is an alphabetical paper doesn't attempt to distinguish the authors' contributions, so by default they are considered equal. The AMS statement merely describes this practice; it doesn't claim it is good or bad, and certainly doesn't propose any changes to it. Commented Jun 8, 2015 at 0:51

Since the other author's "non-negligible contribution" did not actually make it into your paper, I think an acknowledgement would be sufficient. Making him/her a co-author would imply that some of the work in the paper is not yours --- and that would be a misrepresentation.


Some disciplines usually use alphabetical order, but this is by no means mandatory. In fact, I would say that one of the rules of writing papers with others is that you should have a conversation between all co-authors to discuss precisely this point: who should be a author, why, and in which order. In some disciplines, such as pure math, this most often leads to alphabetical order, which is used to indicate that everyone contributed to the same degree (or, at least, nobody feels strongly enough to push for having their name listed first). But other disciplines do it differently, including for example applied mathematics where many papers are written to indicate one of two things:

  • The first author really did more work than the others.
  • The first author is junior and needs a first-author paper more than others. (For example, almost all of my more recent papers have my students and/or postdocs listed before me -- because I have tenure and don't need these papers more than I do -- even though oftentimes I would have a fairly good argument for being the first author, having done a very substantial amount of work.)

So, in your case, I would suggest talking this trough with your co-authors: who did how much, who are the possible authors, what order should they be listed in, and then come to a joint conclusion that does everyone justice. I certainly don't see a stigma in figuring this out, rather than just going with the default alphabetical order.

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    " In some disciplines, such as pure math, this most often leads to alphabetical order, which is used to indicate that everyone contributed to the same degree (or, at least, nobody feels strongly enough to push for having their name listed first). " I disagree with this on two points. First of all, "most often" is too weak: the order is alphabetical more than 99% of the time, to the extent that non-alphabetical order looks like an error of one kind or another to many. Second, it is absolutely false that alphabetical order means that everyone contributed to the same degree. Commented Jun 7, 2015 at 21:30
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    As a test case, I just looked at the 100 most recent multiply authored papers in the Journal of the American Mathematical Society. Number of times alphabetical order was preserved: 99. (The exception has Math Review MR3264763. It is in pure mathematics. I couldn't find a clear reason for the reversal.) Commented Jun 7, 2015 at 21:42
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    Putting someone as first author just because they need a paper more than others is, I think, a terrible system. (This is a critique of the system, not of individuals who follow it out of necessity.)
    – Kimball
    Commented Jun 8, 2015 at 2:09
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    In fields where author order is always(±ε) alphabetical, nobody(±ε) needs a first-author paper more than anyone else, because first-author papers are worth exactly the same(±ε) as any other paper.
    – JeffE
    Commented Nov 29, 2015 at 0:11

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