On alphabetical authorship order in philosophy

I have recently been thinking about alphabetical authorship norms in philosophy. On those rather rare occasions when philosophers co-author a paper, they must decide whether to list authors alphabetically by surname or to apply another ordering convention. The most common alternatives include ordering by individual contribution, by responsibility for funding acquisition, by coin toss, and so on.

Knowing the prevailing norm for authorship order matters, because this norm likely shapes how work is perceived. For example, if you and your co-authors decide to list names alphabetically in an environment where most people rank them by contribution, casual readers might assume that a later-alphabet colleague pulled less weight than they actually did. On the other hand, if you ordered by contribution but the resulting list happened to be alphabetical in a field that already leans toward alphabetization, that deliberate choice might be obscured.

Data

Through a project I am working on with Hein Duijf, I have a large dataset of philosophical literature lying around that will allow us to track this. The dataset was created by using the PhilPapers list of philosophy journals, which contains more than a thousand titles, and extracting their corresponding bibliometric data from OpenAlex, resulting in a collection of 1.4 million articles. This dataset is very expansive because PhilPapers adopts a rather liberal approach to classifying journals as philosophy journals. For our purposes, this is beneficial, as co-authored work is likely to occur more frequently at disciplinary borders, where scholars engage in interdisciplinary collaborations.

We can quickly assess how common co-authorship is in philosophy by examining the length of author lists. Figure 1 shows that the vast majority of philosophical articles are single-authored, with a small minority of zero-author contributions. These largely reflect institutionally authored items (letters from editors, published bibliographies, or lists of books received). After filtering out the most egregious entries by manually reviewing the fifty journals with the highest article counts and removing any that clearly fell outside philosophy, our final sample comprises 169,415 articles with more than one author.

All code for this project is available on GitHub, which also includes the complete list of excluded journals.

Measuring intentional alphabetization

Now, how do we measure the alphabetization rate in philosophy? It’s more involved than simply counting the papers whose author lists appear in alphabetical order, because other conventions, like randomizing author order or ranking authors by contribution, can also yield alphabetical sequences by accident. We therefore need to adjust the raw alphabetization count by the level of alphabetization expected under chance alone.

Following Waltman (2012), I compute an intentional-alphabetization score for each paper as

\[s = \frac{A - p}{1 - p}\]

where \(A=1\) if the published author list is alphabetical and \(A=0\) otherwise, while \(p\) is the probability that the same set of names would appear in alphabetical order by pure chance. Averaging s over all papers in a field yields a field-level index that ranges from 0 to +1, with values near +1 denoting a strong, or total alphabetical norm and values near 0 its absence.

I diverge from Waltman’s analytic approach for \(p\): instead of using the closed-form \(1/n!\) (with \(n\) the number of authors), I estimate \(p\) by repeatedly shuffling each paper’s author list programmatically and recording how often the permutation is alphabetical. This Monte-Carlo procedure introduces negligible extra noise but gracefully handles edge cases such as repeated surnames, which are common among relatives co-authoring and many Asian names.

Figure 2 traces these values over time. A little less than half of the multi-authored articles in our sample appear in alphabetical order. Remembering that most collaborations in philosophy are by two people, we can assume that a good part of these can plausibly be chalked up to chance. The share of deliberately alphabetical ordering (or alphabetization index) is much lower, peaking at about 20 percent in the aughts and drifting down into the 10–15 percent range in recent years. Taken together, these numbers indicate that philosophy lacks a robust convention of alphabetical co-authorship, and that the little intentional alphabetical ordering that once existed has been shrinking.

Comparing Journals

How do these results look when we compare different journals? For a first look, I took the list of top journals proposed by De Bruin (2023). The resulting average intentional-alphabetization values, together with bootstrapped confidence intervals are shown in Figure 3. For my own interest, I also included two philosophy-of-science journals. Note that Ergo is absent from the dataset and the Proceedings of the Aristotelian Society is excluded because the dataset contained only two co-authored papers. As I am mostly interested here in contemporary conventions, I also included only papers from the last fifteen years.

We note considerable variation in intentional alphabetical ordering among philosophy journals. The highest level of intentional alphabetization is found in the Journal of Philosophy with around 60%. The average intentional alphabetization rate among all of these journals is roughly 40%.

This aligns with the 38.8% Waltman reports for the Web of Science “Philosophy” category for the years 2007–2011. The value is far lower than that for mathematics (73.3%), finance (68.3%) and particle physics (56.7%), but noticeably higher than those typical of other humanities like history (29.9%) or linguistics (15.6%). It is also considerably higher than the global average we found in our data shown in Figure 2. While it seems like Waltman appears to have observed alphabetical ordering in philosophy essentially at its peak with his sample, there is still a roughly 18 percentage point difference. I couldn’t reconstruct Waltman’s sample, as I don’t have access to what the Web of Science category of philosophy contained thirteen years ago, but I suspect that it took a relatively narrow view of philosophy. E.g., it separates out history and philosophy of science as a separate category (18.5%).

To investigate which sorts of journals shift the average up or down in our sample (and therefore might explain this discrepancy), I extracted those with the highest and lowest alphabetization values over the past fifteen years. The plot displays only journals with more than 100 data points. I also removed every journal whose mean alphabetization value falls below zero; such a negative score signals that the papers in the journal systematically resist alphabetical authorship ordering. Closer inspection suggests that this pattern usually arises because a single person appears as co-author on many, or most, of the articles. This could be an intentional and somewhat worrisome editorial practice, or merely a coding error in how editors were recorded in the database.

We see that the highest-scoring journals are basically logic and mathematics-venues, (and Ethics for reasons that I couldn’t determine.) so it is no surprise that they follow alphabetical conventions. Several other leading philosophy journals end up in the 40%–60% range of intentional alphabetical authorship ordering. At the bottom sit journals with almost no deliberate alphabetical ordering. Here we see a lot of medicine and nursing ethics, as well as a number of non-English journals. I also suspect that less analytical outlets tend towards less alphabetical ordering. Overall, I suspect that both the highest and lowest amounts of alphabetical ordering in our sample of philosophy are imported from the bordering disciplines in which philosophers author as well.

Rankings vs. the alphabet

While reviewing the original journal ranking, it appeared to me that the more prominent journals seemed likelier to adopt alphabetical authorship. I ran a quick regression (weighted by number of articles in each journal) using De Bruin’s awareness-adjusted quality score. This score is derived from a survey in which philosophers rated journals for quality and reported how familiar they were with them, which taken together should yield a reasonable proxy for prominence.
The models suggest that there is a weak relationship. We explain only about 12% of the variance (and therefore would fare very badly trying to predict alphabetization rates from journal rank alone). But higher-ranked journals still show measurably more intentional alphabetization \(r(36)=.34,\,p=.036,\,R^{2}=.12\). The model predicts 25 percentage points more intentional alphabetization in the top-rated journals than in the lowest-rated ones.

Why? One thought is that top Anglophone journals tilt toward formal work and so quietly import authorship norms from formal disciplines. Another is that authorship-order disputes are less lenient in high-impact venues; collaborators may therefore converge on external, low-friction conventions.

Final thoughts

So, where does that leave us? We have seen, contemporary philosophy lacks a strong, field-wide convention of alphabetical ordering, and the limited practice that does exist appears to be disappearing in recent years. Alphabetization is somewhat more common in formal, high-impact venues, yet even there intentional alphabetical ordering reaches only about 40–60 percent. Casual readers, therefore, cannot be expected to infer that an alphabetical byline reflects a deliberate choice rather than some other dynamic, especially if they usually read work from throughout the discipline. In the most formal subfields, alphabetization may work well as a choice, because the conventions are comparatively robust. By contrast, in areas such as history and philosophy of science, or in applied ethics, it seems unlikely that it is reliably interpreted.

Note on the use of generative AI: a lot of the code for this analysis was produced using OpenAI’s o3 model. The text of this blog post was dictated to MacWhisper and edited afterwards. Depending on your general view of my work, you may adjust your estimate of the results’ quality upward or downward accordingly.