My co-authors and myself have recently submitted an article (in the wider field of economics) to a journal and we now wish to submit the same article to a conference while the article is still under review at the journal. There will be no such thing as published conference proceedings and as far as I can tell not even a working paper version of the article will be made available online.
Is there anything unethical about doing so, i.e. submitting an article to a conference while it is under review for a journal?
I am asking since for a journal submission one would write in the cover letter something along We confirm that the article has not been published or is under review elsewhere. Now I am drafting the cover email to the conference submission and I was wondering whether I should include a similar phrase and if so what to write?
For a conference submission, should (must/can) I indicate that the submitted article is currently under review in a journal, or would I not want to write any such sentence?
Currently I would not, since as long as the article has not been accepted it is still work-in-progress and as such perfect to submit at a conference (economics conferences also tend to attract fairly advanced-stage papers in my perception).
I have asked my co-authors, who are experienced and established professors in the field, on the first question and they both saw no problem. I am asking for a second opinion to calm my mind since I am likely over-thinking the issue and unsure how to address it.
I have found one related question:
Simultaneous submission short version to conference and full version to journal
but in that field it is common to have a conference paper first, often followed by a journal article. As I stressed above, the difference here is that there is no conference publication as well as the very different fields.
Submitting journal version of an article while conference version is still in review asks about the other way round, submitting to a journal while the conference article is still under review. Here is different in that the article submitted is the same, there is no conference publication and the order is the other way round.