A study published in the Journal of Informetrics in 2026, “A CRediT-based quantitative study of co-corresponding authorship: Collaboration patterns and contribution distribution” (DOI: 10.1016/j.joi.2026.101796), is one of the first large-scale analyses to combine structured CRediT contribution statements with co-corresponding authorship (CCA) data. Where earlier bibliometric work on shared corresponding-author status relied on byline position and counts alone, this study uses the fourteen CRediT roles themselves as the unit of analysis — asking not just how many corresponding authors a paper has, but what each of them actually did.
What the study did
The researchers drew on a large dataset of PLOS-published articles, which is one of the few large open corpora where structured, role-by-role CRediT statements are consistently attached to bylines rather than left as free-text contribution paragraphs. From that dataset they isolated papers with co-corresponding authorship — more than one author formally designated to handle post-publication correspondence — and compared them against single-corresponding-author (SCA) papers.
To move beyond simple role counts, the authors introduce two purpose-built indicators: a Contribution Index, which weights an author’s CRediT roles to produce a comparable measure of contribution magnitude, and a Role Prominence Score, which captures how central an author’s assigned roles are to a given paper relative to their co-authors. Together these let the study quantify, for the first time at scale, how contribution is actually distributed among authors who share the corresponding-author designation, rather than assuming it is split evenly.
Key findings
Co-corresponding authorship tracks with broader, more distributed collaboration
CCA is more common in fields characterized by intensive team science, and papers using it tend to involve more co-authors, more institutions, and more geographic regions than comparable single-corresponding-author papers. The practice reads less as a formatting convention and more as a marker of larger, more distributed collaborations that outgrow a single point of contact.
CCA papers show a citation advantage over SCA papers
Papers with co-corresponding authors showed significantly higher citation impact than otherwise-comparable papers with a single corresponding author. The study frames this as consistent with CCA papers reflecting broader, cross-institutional collaboration rather than the shared byline designation itself driving citations.
Contribution magnitude rises with later byline position among co-corresponding authors
Using the Contribution Index, the study finds that among authors sharing corresponding-author status, contribution magnitude tends to increase with later position in the byline — the opposite of the assumption that corresponding-author weight concentrates at the front of the author list. This is the study’s most direct challenge to a common shorthand: that a corresponding-author tag near the end of a byline signals oversight rather than substantive contribution. The Role Prominence Score results reinforce this, showing later-listed co-corresponding authors frequently holding prominent roles rather than peripheral ones.
Why this is a new data point, not a restatement
CASRAI has covered adjacent ground on shared-credit authorship before, and it’s worth being precise about what each piece actually establishes, since the terms get used loosely:
- Our guide to co-corresponding authors covers how journals define and format the role — publisher policy, ICMJE’s silence on the practice, and why it sits entirely outside the 14 CRediT roles as a piece of administrative infrastructure rather than a contribution category.
- Our news coverage of rising equal-contribution authorship tracked a different phenomenon — explicit “these authors contributed equally” tags, concentrated at first-author position, rising from roughly 19% to over 30% of PubMed/PMC articles between 2015 and 2024 — and was explicit that equal-contribution tags and CRediT are distinct systems that a paper may use independently.
- Our piece on the gender gap in corresponding and senior authorship looked at who holds the corresponding-author role by gender, and suggested CRediT statements as a complementary lens on research leadership beyond positional convention — but did not analyze CRediT role data directly.
None of that prior coverage quantified what co-corresponding authors actually do, role by role, using CRediT data itself. That is the gap this study fills: it is the first of these to use CRediT contribution statements as the measurement instrument for analyzing how credit is distributed within a shared corresponding-author byline, rather than treating co-corresponding status as a binary flag.
Limitations worth flagging
The dataset is drawn from PLOS journals, which have mandated structured CRediT statements for years and are consequently one of the cleanest available sources of this data — but that also means the findings reflect PLOS’s disciplinary mix and editorial policies specifically, not publishing at large. Findings on citation impact and collaboration breadth are correlational, not causal: the study does not establish that adopting co-corresponding authorship itself produces more citations or broader collaboration, only that the two are associated. As CRediT statements become mandatory at more publishers, similar analyses across other CRediT-adopting venues (Cell Press, PLOS, and others tracked in CASRAI’s own CRediT taxonomy reference) will show whether these patterns hold outside a single publisher’s corpus.
What this means for research administrators
For institutions and journals evaluating co-corresponding-author claims — in tenure files, grant reporting, or authorship disputes — this study is a caution against reading byline position as a reliable proxy for contribution weight among co-corresponding authors. If later-listed co-corresponding authors are, on average, contributing more rather than less, then a policy or reviewer that discounts a corresponding-author claim based on list position alone risks under-crediting exactly the contributors CRediT statements were designed to make visible. It also strengthens the case, already made in CASRAI’s co-corresponding author convention entry, for treating CRediT role statements and corresponding-author designation as two separate, complementary pieces of metadata rather than assuming one implies the other.
Frequently asked questions
What is the Contribution Index used in this study?
It is a purpose-built metric from this study that weights an author’s assigned CRediT roles to produce a comparable measure of contribution magnitude, allowing researchers to compare how much different co-corresponding authors on the same paper contributed rather than treating the shared designation as an even split.
What is the Role Prominence Score?
A companion metric from the same study that measures how central an author’s CRediT roles are on a given paper relative to their co-authors, used alongside the Contribution Index to characterize contribution distribution among co-corresponding authors.
Is co-corresponding authorship the same as equal-contribution or co-first authorship?
No. Co-corresponding authorship is a designation about who handles post-publication correspondence and is independent of both equal-contribution tags (typically applied at first-author position) and CRediT role assignments. A paper can use any combination of these three conventions, or none of them — see CASRAI’s co-corresponding authors guide for how the designation is formatted and governed.
Does having co-corresponding authors increase a paper’s citation count?
The study found CCA papers have higher citation impact than comparable single-corresponding-author papers, but the association is not shown to be causal — CCA papers also tend to involve broader, more distributed collaborations, which is a plausible independent driver of citation impact.
Where was this study published?
In the Journal of Informetrics (Elsevier/ScienceDirect), DOI 10.1016/j.joi.2026.101796.
