Publication rates in Mathematics
Here is the AMS culture statement on publication rates in mathematics. Even the best young mathematicians publish average of two or fewer articles per year.
[extended comment not really answering the question, but an answer of sorts nonetheless; feel free to downvote!]
[edit: the thoughts below reflect my subjective opinion and are not meant to be interpreted as an expression of objective truth]
This question is, in a sense, flawed. You are asking about studies of a certain number $X$. Taken on its own this may be a reasonable question; the problem is that your stated motivation for why you are interested in $X$ is that you would like to (or your university would like to, and you seem willing to go along with it) use $X$ in a way that many reasonable mathematicians would agree is not just useless, but is in fact extremely harmful. How can anyone answer this with a straight face? Personally I would not answer even if I knew of such a study! There may be valid reasons to study $X$ and to be interested in it, but the motivation given for the question completely undermines the discussion.
With that said, it's important to emphasize that even across different areas within mathematics, there is a very large variation in
$X=\,$the average rate of publication for a mathematician working in that area;
$Y=\,$the average length of a publication;
$Z=\,$the average number of coauthors of a paper;
$W=\,$the average quality and impact of a paper (which are of course vaguely defined notions which there is currently no agreed upon way to quantify).
By agreeing to have your Faculty of Science and Engineering use $X$ as the measure of anything without making any attempt to take into account $Y$ and $Z$, let alone the much more intangible and ultimately most important parameter $W$, you would be allowing your university to create a hugely distorted image of your and your colleagues' research output. The fact that there will be some normalization factor that would ostensibly bring mathematics on par with other disciplines is completely irrelevant. So, as I said, although I'm sure it was well-intentioned, the motivation for the question is fatally flawed in my opinion. It may be worth having a discussion about average publication rates in the context of how to measure the productivity of mathematicians and whether it's a good idea to try to do so, but that would be a separate question that would need to be phrased in those terms.
From an answer of mine on academia.stackexchange.com:
Italy introduced a few years ago a habilitation process which involves heavy bibliometric evaluation, and in the process they computed median values for all the professors in Italian universities for:
- number of papers published in 10 years
- citations per year
- a sort of normalized H-index: the number h such that the person has h papers with score >=h, where a paper published Y years ago with C citations has score 4C/Y. (more precisely defined here (Italian) and here).
The medians are separate by discipline and academic role (associate and full professor only --- not for assistants, unfortunately). You can find them here: associate full, and a legend for the codes of the scientific disciplines is here. The documents are in Italian, but you can google-translate them (or guess the meaning of most words, it's not too difficult for an English speaker).
For instance, in computer science (01/B1) the medians for an associate professor are
- 10 journal papers / 10 years,
- 9.15 citations / year
- "contemporary H-index" 5.
and for a full professor
- 12 papers / 10 years
- 14.8 citations / year
- "contemporary H-index" 6.
The calculations are of course imperfect, but they are very interesting to browse and give an idea of how wildly these numbers vary across different fields. For instance, the typical professor in nuclear physics (02/A1) publishes 59.5 papers over 10 years and gets over 104 citations per year, while one in mathematical logic (01/A1) publishes 5 papers in 10 years and gets 1.74 citations per year.