Who do I email about a question on a paper?

Question

I want to ask the authors of a paper if they have thoughts on an application of their work. I'm not sure who to email.

The first author is a grad student, who is supervised by the last author - however, the authors are in alphabetical order so I'm not sure if there is any meaning to the ordering. The paper is in economics, which traditionally goes alphabetically, I believe.

Should I email all the authors in one bulk message? Just the professors? Choose one of the authors at random and email them?

Answer 1

Papers usually have one (or more) designated corresponding author, or “contact author”, or “author to whom correspondance should be addressed”. That's whom you should contact.

Sometimes it's indicated by a footnote, an asterisk, or at the end of the paper. Sometimes, it's indicated by the fact that only corresponding authors have their email address listed.

If there is no corresponding author, then email either the first author or senior author, depending on the nature of your question and how confident you feel in communicating with them. I would refrain from copying the email to all authors (except maybe if there are only two): if he wants to, the author you will write to can forward your query to others.

Answer 2

While this involves a little more work, it might be possible to do some digging to see who's the prime mover on the paper. For example, if one of the authors has a series of papers on the topic, or if it's part of an author's thesis, and so on. If you're able to find such a person, then it might help to email them directly. If not, then @F'x's solution is fine.

Answer 3

In fields like pure mathematics, where authors are given equal credit, I'd recommend e-mailing all the authors unless there are an awfully large number of them or special circumstances apply (you know an author personally, you happen to know that your question is most relevant to a specific author, etc.). The reason is that if you single out a specific author, then the other authors may try to guess why. Is it because the author you chose is the most famous? Because you mistakenly think they deserve most of the credit? Because you are ignoring a woman in favor of her male coauthor? Of course nobody will know why you made your choice, so they won't get too upset about their speculations, but this is not a great start for your interactions with the other coauthors.

If you e-mail several people about a paper at the same time, it's best to send a single e-mail. Every so often someone will send the same message separately to me and to a coauthor, which just increases the chances that we will waste time by both replying without ccing the other.

Answer 4

This applies to the case where there is no corresponding author.

Talking about my field (applied CS), where many experiments depends on experiments which are not always easily repeated, and code are usually not available*:

I think it is more effective to go directly to the supervisor (or supervisors) - [last and second to last authors - since this is the order usually followed in applied CS]. These authors usually takes higher care of their reputation in the field. Because of that, they will force their students (i.e. first author and/or second) to give explanation. (example: This happened when my supervisor received a question about a paper of his with another post-doc. I am sure that my supervisor did not work much on the details of the paper, but his name must be included - that s an engineering tradition I believe. The supervisor made sure to call the post-doc and asked for explanation. The supervisor forced the the post-doc to send an email back to the question sender).

If you send a question directly to a PhD/Msc student, he would ignore you most likely - from my experience. Because many PhD students hide their mistakes intentionally - just to have their thesis accepted later. (example: I heard a PhD student that he made some mistakes in his MSc thesis and he hid them intentionally. He said "this is to make whoever work on my work find trouble matching the paper results and the new experiments results".

But honestly, at the end, we cannot generalize.

(*)This one of the biggest mistakes in applied CS.