I'm an economist by training. I've used LaTeX since 1991, ever since I wrote a couple of working papers with an early version of LaTeX. I continue to use LaTeX for my own working papers, journal articles, and some of my other professional publications.
I am the principal author of the selnolig package, which lets LuaLaTeX users automatically suppress typographic ligatures that are inappropriate because they span morpheme boundaries, for both English and German language texts.
I once edited an entire conference proceedings volume in LaTeX. This was a fabulous learning experience, especially as I got to work closely with a professional book designer from a very early stage of the editing and publication process. For another organization I used to work for, I wrote a LaTeX package to implement the style and layout requirements the organization had chosen to impose on working papers written by its professional staff (mostly its economists). This package (i) helped free up much of the authors' time that would otherwise have been wasted on figuring out how to implement the organization's stylistic requirements in LaTeX -- the guidelines had been written (unsurprisingly...) primarily for users of MS Word -- and (ii) actually convinced some of the organization's economists to make the switch from MS Word to LaTeX in order to write their working papers more efficiently.
[I've just been asked to write a minimal example. What's that?] (http://meta.tex.stackexchange.com/q/228/5001)