I worked briefly as a free-lance editor before quitting because I'm not willing to do this highly tedious and technical work for less than $20/hr yet often found myself making half that. The pay per assignment is based on the number of words (short, medium, or long) and on an assessment of the difficulty. These assessments are often wildly inaccurate -- for example, anything submitted from China is invariably difficult to edit, but such manuscripts are often assessed as "average". Occasionally, you'll get something that looks as if it was translated by Google. Such papers cannot be edited at all, and to accept them from a paying client is, I think, unethical.
Some of the managing editors are quite good, but by no means all. As feedback one can download the final MS as modified and reviewed by the managing editor. Occasionally, gross errors were introduced into my edited manuscripts.
Pros: There is work to be had and you get to set your own schedule.
Cons: Uneven editorial staff at the management level. Poor assessment of assignment difficulty, resulting in very poor pay for this kind of skilled work. There is (by design) no way to review a paper before accepting it as an assignment.
There is work to be had and you get to set your own schedule.
Uneven editorial staff at the management level, Poor assessment of assignment difficulty resulting in very poor pay for this kind of skilled work, There is (by design) no way to review a paper before accepting it as an assignment