Submitting extra/optional application materials?

In our September "how can we help you?" thread, 'job applicant' writes:

Should applicants submit materials that are "optional"? Will it hurt our chances if we don't? This is a general question, but the ad I'm thinking of gives very specific instructions about the documents the applicant must submit and does not mention any optional documents. It's only while working on the application through the university's website that one sees one may upload additional optional documents (research statement, cover letter, etc.). If submitting optional materials increases one's chances, I'll do it, but if it doesn't, I'd rather not spend the additional precious time it takes to do it. And if it will or even just may make a difference, I wonder why these documents aren't just listed as required.

This is a great question. Someone recently asked me, for example, whether they should upload a diversity statement if they have the chance, in cases where a job ad mentions diversity but doesn't explicitly ask for a diversity statement. I guess I'm inclined to think that candidates should upload exactly what is asked for (and no more), as uploading additional documents might rub search committee members the wrong way (viz. the applicant trying to give themselves an unfair advantage). However, I'm not sure about this. 

What do readers think (not just about the example I gave, but about job applicant's query in general)?

Comments

[Anon]

Marcus, as a potential solution to the diversity statement issue, I have mine as part of my teaching portfolio. So if the job ad asks for a teaching portfolio or "evidence of teaching effectiveness," they automatically get my diversity statement (unless they specify that they only want specific things like evaluations and/or teaching statement, which some do, but i also address diversity directly in my teaching statement and often expand that portion for jobs that dont mention diversity statement or dont want the whole portfolio).

[Prof L]

This seems like a peculiar case -- the ad specifies only a couple of things, and then some (standard) items are listed as optional to upload on the website: a research statement and cover letter. In this case, I would upload them, since I would imagine the vast majority of candidates have those items ready at hand and will upload them.

When I was on the market optionals were usually "extras", like an extra writing sample or an extra letter. I would supply those materials if it was easy or served some purpose (like if the ad was for my AOS but specified that they would like someone with a strong research interest in X, I would upload an extra writing sample in X, if I had it).