I have come across working papers in economics. I have seen 'papers in progress' listed on some researchers website but have never seen the idea of working paper as is common in economics. Just curious if this is practiced in some sub branch or was used at some point of time in history.
They are not common in my field(s) (numerical methods, high performance computing, etc.), but where journals are the primary, high prestige publication venues, we sometimes use conference talks to present works in progress. These talks are often accepted to the conference or one of its minisymposia on the basis of nothing more than light review of a one-paragraph abstract. This gives the author room to be a bit speculative in their abstract and talk about work that may or may not be complete by the time of the meeting. Later, if it works out, the material is turned into a journal article for publication.