Here are two tasks that mods on most SE sites perform, but unfortunately not on Econ.SE:
1. Move lengthy discussions in comments to chat
For better or worse, the default position of SE is to move lengthy comment chains to chat: see e.g. this Meta discussion.
This has not been done at all and we regularly have chains with 20+ comments.
2. Protect questions
Sometimes some questions start appearing on Hot Network Questions and attract low-quality questions. This is what the Protect function is for.
I assume mods always have access to this function? (If not, I am mistaken and please ignore me here.)
I'm not sure how but with this recent question, it was only after some time (and after 9 answers had been written) that the "Protect" function appeared to me and I was able to activate it. It would probably have been better if a mod could have Protected the question earlier. (Indeed, I flagged the question asking a mod to protect it, but this was not done.)