I am a PhD student in the USA in the field of Aerospace Engineering. My supervisor had mentioned that he will be the sole 'corresponding author' in all journal publications. Consequently, I am not the corresponding author in any of my publications.
I have noticed that some postdoc fellowships ask for the 'number of papers as a corresponding author'. This was new to me and I was wondering if it is common to use 'the number of papers as a corresponding author' as a criterion to judge candidates?
This is a personal view and it may not be valid in all fields, I realize. But my view is that "corresponding author" is a job, not an honor. It is who should be contacted by the editors and later by readers for questions about the paper. With this view, it is best that it be someone with stable contact information, now usually an email address. That suggests that students may not be the best choice if they lose their university email after graduation.
"Principal author" or "first author" in some fields is a completely different concept. In some fields the concepts are foreign and not used.
Principal author, in some fields refers to the PI of a lab. The one that supplies the infrastructure in which research can be done. In some fields they are listed last. In some fields it is interpreted that they had little part in the actual research beyond infrastructure and maybe general guidance. Sadly, in some fields, some interpret this as "this person really did this work and the others are just being carried along".
First author, in some fields, is usually listed first in the ordering of authors on the document and the implication is that they did the majority of the work, perhaps (or not) coming up with the research question and driving the whole project intellectually. Those fields in which first authorship is considered important often have bitter fights over who should be listed first. I find this sad.
In you current situation, however, for purposes of applying for jobs and writing CVs, I suggest that you just add a note at the end that the supervisor insists on being corresponding author (as I think is appropriate). This could short-circuit any feelings that you aren't adequate in some way.
As for grant applications, I think it would be foolish (though I can't rule it out) for those evaluating an application to look at such things and give them weight over what is being proposed in the grant and the information there that backs up the application. Maybe first authorship would give a bit of confidence in those fields in which it is a vital concern.
In biology, a corresponding author is generally a person with overall responsibility for the research. It is often, but not always the last author listed. While the first author is usually the person that did the most work, the corresponding author is expected to be au fait with the details of the work of all people listed as authors on the paper (which the first author may or may not be). They are expected to continue to have access to all records and data related to the paper in perpetuity.
Research in biology is often conducted as part of a research program. The corresponding author will generally be the person who is in charge of the complete program, not just the single piece of research being conducted here. The goals and aims of the larger program will be determined by them, even if the idea for the individual paper is not theirs. Thus, they will understand how the research fits into the larger goals and aims of the program, how it relates to work that came afterwards, etc.
Thus it is normal that the person nominated as corresponding author is a senior person. Often the last author (senior author as some people say). A junior person being the corresponding author would suggest a degree of autonomy and independence (it would suggest that the last author was last author purely out of senority, rather than because they were actually responsible for the research). This may be exactly what funders of postdoctoral fellowships are looking for.
So yes, being corresponding author is advantageous, but it is unusual for a postdoc, at least in biology.
To pass probation (similar to tenure in the US), I had to have 3 papers as first, last OR corresponding author. To get promoted I had to have 3 corresponding author papers. So for us at least, it's not expected that we will be publishing corresponding author papers until our first promotion after tenure.
Much of this is field dependent. I'm a public policy phd student, full disclosure. But, corresponding author is just who you reach out to for matters of code (in my case) data and other matters. It also is conferred, naturally, based on contribution (ideally). So, so long as you played a central role in the developing of the topic, the code, the design and all quintessential elements of the research process, you can then (theoretically) become the corresponding author.
But note, in my case, I'm far enough along in my development that I can ask my mentor if he wants to work with me on something, where I'm lead author. Because I have my own research questions and I'm generally always finding new stuff to work on or study, and I don't need anyone to hold my hand to do research (not saying that you do, by the way). So yeah, it's field and context dependent.
