What factors influence views on last authorship in ecology?

As summarized in my post giving the major results of our authorship survey, there seems to have been a rapid shift in views on last authorship in ecology. When I started grad school, the predominant view was that the last author was the person who had done the least work. (Indeed, I am last author on a paper from when I was a grad student because I did the least work on the project.) But the survey found that 43% answered a solid “Yes” to the question “For ecology papers, do you consider the last author to be the senior author?” An additional 43% answered either “It depends, but probably yes” or “Not sure, but probably yes”. Thus, 86% of respondents view the last author as the senior author.

As far as I know, we don’t have great data across time regarding views on this. The best comparison I know of is to a smaller survey done in 2010 by Ethan White. (I based the first draft of my survey on Ethan’s.) In that, only 19% of respondents answered “Yes” to the same question, with an additional 33% answering “Not sure, but probably yes”. (That earlier survey didn’t have the “It depends, but probably yes” option. That was added in based on feedback on the initial survey I drafted.) So, while it would be nice to have more data on this, it seems that views on last authorship in ecology have probably shifted pretty rapidly.

The goal of this post is to explore whether there are factors that are associated with views on last authorship.

Prior to analyzing the data, my expectations were that people:

  1. with more recent PhDs;
  2. who do primarily molecular research; and
  3. in Biology departments (rather than EEB or Nat Res departments)

would be more likely to view the last author as the senior author. I also wondered if geographic location and the amount of interdisciplinary work would influence views, but didn’t have specific hypotheses. I haven’t done any formal hypothesis testing (even though it’s okay to use statistics for exploratory analyses!) I decided before doing analyses that, in cases where I was comparing two groups (e.g., basic vs. applied), the difference would need to be about 10% before it seemed noteworthy. That number is somewhat arbitrary, but I wanted to have something in mind at the start.


Were people who got their PhD more recently more likely to view the last author as senior author? The trend isn’t overwhelming (Figure 1A). Current students and recent PhDs had the highest percentages for the “yes” options, but the only major difference seems to be that people who do not have a PhD and who aren’t a current student had different views (but with the caveat that this group represented only 2% of responses). If I binned the data into 0-10 years since PhD and 11+ years since PhD, I’d probably get a difference, with the latter being less likely to view the last author as senior author. But the 11-15 years since PhD group is most extreme, so I’m hesitant to do that comparison.

Figure 1. Results of question on whether the last author is the senior author, broken down into different groups: A) years since PhD, B) primary research area, C) department type, and D) basic vs. applied research.

Did research area influence views? The pattern that seems most striking to me in the data related to research area is that the two evolutionary biology groupings (“Organismal Evol” and “Mol Evol” in Figure 1B) were the most likely to give one of the “yes” responses. My thought that the molecular folks might be more likely than organismal folks to view the last author as senior author held for ecologists but not for evolutionary biologists (Figure 1B); however, it’s worth noting that the most straight “yes” answers were from people doing molecular evolution.

I was completely wrong in thinking that folks in ecology and evolutionary biology (EEB) departments would have different views than those in Biology departments (Figure 1C). Instead the difference was between EEB/Bio folks and those in Natural Resources departments. Overall, people in Natural Resources departments were much less likely to view the last author as the corresponding author. This probably helps explain the difference between those doing basic and applied research (Figure 1D), but that difference didn’t reach my 10% threshold.

There also seems to be interesting geographic variation (Figure 2A). Focusing just on North America vs. Europe (because those are the only two where we had substantial numbers of respondents; see Table 3 in my earlier post), Europeans were more likely to view the last author as the senior author.


But the most interesting pattern to me overall is that there is a clear relationship between the frequency of doing interdisciplinary research and views on authorship, with those doing the most interdisciplinary research being the least likely to say the last author is the senior author (Figure 2B). This surprises me! If I’d been forced to guess ahead of time, I would have predicted the opposite pattern. (It actually surprised me so much that I pulled up the data in Excel and manually sorted things to make sure I hadn’t messed up the code somewhere. My manual sorting and binning matched the above.) I would love to hear thoughts about this! It seems counter to the idea that ecology traditionally has had less of a view that the last author is the senior author. My best guess is that that is a view based on ecology vs. medicine (or molecular and cell biology), and that the interdisciplinarity result is driven by people doing interdisciplinary work with other disciplines (e.g., geology, engineering). I don’t know what the traditional views on last authorship are in those fields.

Those are all the analyses I had planned related to the first question. If you think I missed something interesting (for which we have poll data!), let me know. And I’d love to hear thoughts in the comments. I’ll continue to post results as I get them written up.

Acknowledgments: The same ones from my earlier post apply, but I especially want to note that the figures in this post only exist because of help from Rayna Harris.

23 thoughts on “What factors influence views on last authorship in ecology?

  1. I’m struck that there’s not *that* much variation here. In every subgroup people who think last author = senior author are at least 2/3 of respondents. Another sign that the last=senior convention really has taken over ecology.

  2. Pingback: Last and corresponding authorship practices in ecology: Part 1 | Dynamic Ecology

  3. Not sure about engineering or geology, but in my informal recollection/experience, social scientists are very unlikely to view last author as senior author, and so when I collaborate with them, we are much less likely to use that convention.

  4. It would be very interesting to get some data from the journals that do require author attribution of contributions. From this you could see the proportion of multi authored papers with last author being senior author. Wouldn’t take long to get for Science, Nature, PNAS and PLoS One which I think all require statements.

    • That’s right. A more objective evaluation is possible if data are collected from journals that require statements about author contributions.

  5. I also suspect from my own data that only a very small percent of multi authored papers in ecology actually have the senior author last, because this requires a paper to be written by 3 or more authors, with a junior first author, and a senior author coordinating the project. In reality most papers do not fall in this category: most are collaborations between equals.

  6. In my interdisciplinary experiences with computer science and social sciences, last author = senior author is not a Thing. Author order is in order of level of contribution.

    • Interesting, didn’t know that.

      In some disciplines, even co-authored papers aren’t a Thing, or they weren’t until recently. Philosophy for instance has a strong traditional aversion to co-authored papers that’s only just starting to change a bit.

      • And I’ve read that in mathematics, it’s completely alphabetical. Everyone treated equally.

      • I’m trying to reply to Margaret Kosmala’s comment below but am replying here because I’m not getting a reply button below her comment:

        1) I’m a statistician in a math department, and I agree that in math, the convention is to list authors alphabetically (which seems bizarre to me). In stat, ordering is typically alphabetical or by order of contribution.

        2) I think the “Lab PI goes last” model is less common in math/stat because researchers in those fields are less likely to have a “lab” as such. Similarly, the “Person who got the grant goes last” model is less common because I would guess fewer mathematicians have grants since their research often involves only pencil and paper.

        3) I love your figures! (This is definitely a case where segmented bar charts work better than pie charts.) What software did you use to make them?

      • @Steve: Yes, wordpress leaves off the “reply” after a few replies to a comment, but still threads them below.

        The figures were made with the Likert package in github, which I learned about from Rayna Harris. I think they work really well for this! More on them can be found here:

        My code can be found here:
        The Rmarkdown file is probably the most useful place to look.

  7. “those doing the most interdisciplinary research being the least likely to say the last author is the senior author (Figure 2B). This surprises me!”

    Working with people from different disciplines and research cultures (and more diverse collaborators in general perhaps?) encourages awareness that conventions still vary.
    Even now, in some of the bigger international biophysical collaborations, when the first author is the obvious leader (or there is a small team) the rest generally follow according to degree of contribution, alphabet, or both (grouped) … including sometimes the final place (though not always clear).
    See, e.g.,

    I guess if you were at the end of such lists as a “senior” author in some sense, and had a name beginning with a Z, you might want to clarify that somehow!

  8. Thanks so much for doing this, Meghan! These data are so useful. I imagine that for junior scientists, what is most critical is the disparity between the perceptions of the people who are building careers and the perception of those who are evaluating the track record of those earlier in their career. I

    The age/seniority distribution of the respondents (from the first post) shows that senior scientists 22% of the sample are more than 10 years post-PhD. But with more than 1000 respondents, then this is >200 mid-career to senior scientists. The disparity doesn’t in perceptions doesn’t seem huge, but it is there. This means that people on search committees, tenure committees, single-blind grant panels🙂 and award committees are not necessarily on the same page as the people coming up for review. That a bummer, to say the least.

    • “This means that people on search committees, tenure committees, single-blind grant panels:) and award committees are not necessarily on the same page as the people coming up for review. That a bummer, to say the least.”


      Some tweets from yesterday on this topic:

  9. I did a PhD in applied marine ecology, but strangely my supervisor was a geologist! I always thought that the ‘ecology’ convention was last author = senior. In geology it doesn’t seem that way – it appears to be based on order of contribution….. my supervisor always wanted to be second author on my papers, not last author.

  10. With all the different traditions among so many factors, I find it somewhat surprising that people are not posting to say that these differences are sometimes leading to hurt feelings among collaborators. People like fair but it seems kind of hard to figure out what is fair when trying to apportion credit in a publication through author order given this surprisingly rapid shift in perceptions.

    • I know it does sometimes lead to hurt feelings. I suspect some of it is people being hesitant to talk about that in a public forum.

  11. I agree with Margaret Kosmala’s comments – there is no rule that holds across disciplines and time periods. Despite the widely espoused ideals of ‘author position = importance of contribution’ these are practically unenforceable, and every paper has its own history. My personal experience would only provide a series of examples of how many different ways authorship order could be determined. I’ve published work under 4 different research organizations on two continents and across three disciplines. I’ve seen it all, including: plain old sexism, personal vendettas, political decisions, institutional conventions and so-called “discipline” conventions (originally I trained in paleontology + geology and was told that the last author is the person with the grant funding that paid for the work). And then there are the particularly ugly situations when it comes down to dealing with co-authors that need a particular authorship position to get promoted in a particular institutional framework, or the freebies given to students being pushed out of grad school with “something” to show.

    I’ve arrived at the (admittedly cynical) conclusion that it doesn’t matter what my personal opinion is on the issue of authorship for a particular paper if I’m not the one with the power to make the final call. In the survey, I’d have suggested a question about how many times the respondent has actually been in the position of deciding author order.

  12. Pingback: Recommended reads #81 | Small Pond Science

  13. This is actually quite shocking to me as a wildlife biologist. Any paper that I’ve collaborated on, the author list has been in order of contribution to the actual content of the paper. The fact that this might be misinterpreted is frightening, and I had no idea that “last author” vs. “order of contribution” were even in debate. Seems unfortunate that their isn’t a standard and/or this isn’t discussed more often.

  14. Pingback: Fun ways of deciding authorship order | Dynamic Ecology

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