There are many things that factor into this, but teaching, or professorship are some options. There is also publishing, writing, freelance editorial, editing, copywriting.
In some ways teaching or copywriting are the most open areas of employment in this field. Publishing is more difficult to get into. The locations where employment for publishing exists is more narrow too.
Freelance journalism you can do anywhere, but literary research is a little more focused. A good article could get you in the door of a literary magazine.
I hope this helped a little. Good luck with whatever you decide.