Who Writes Wikipedia?
Wikipedia is large; it contains multitudes.
Is it mostly written by the general public? By a hard core with 4000 members? Well, both and neither. Obsessed volunteers add more apiece, and do the most copyediting, but there aren't very many of them, compared with, you know, the whole world (or wikipedia's readership, whichever is smaller). Specifics are hard to come by, and studies contradict each other.
The most recent study is clever: it doesn't consider each Wikipedia edit to be equal (fungible, an increment to be counted) like previous studies did. The authors got special WMF access (that is, decent statistics) and figured out exactly how many times each contribution to wikipedia was actually viewed by wiki readers:
We introduce the notion of the impact of an edit, measured by the number of times the edited version is viewed. Using several datasets, including recent logs of all article views, we show that an overwhelming majority of the viewed words were written by frequent editors and that this majority is increasing.
As a proxy for the value contributed by an edit, we use the persistent word view (PWV), the number of times any given word introduced by an edit is viewed. [My emphasis.] PWV builds on the notion of an article view: each time an article is viewed, each of its words is also viewed.
Two key insights drive this metric. First, authors who write content that is read often are empirically providing value to the community. Second, if a contribution is viewed many times without being changed or deleted, it is likely to be a valuable.
When they say overwhelming, they mean it.
The graph (annotated by me :P) shows that:
Editors who edit many times dominate what people see when they visit Wikipedia. The top 10% of editors by number of edits contributed 86% of the PWVs, and top 0.1% contributed 44% – nearly half! The domination of these very top contributors is increasing over time. [That makes sense, because a stable, well-liked edit keeps getting veiwed and therefore racking up PWVs as the years go by. -WikipediaBlog] Of the top 10 contributors of PWVs, nine had made well over 10,000 edits. However, only three of these users were also in the top 50 ranked by number of edits. The number one PWV contributor, Maveric149, contributed 0.5% of all PWVs, having edited 41,000 times on 18,000 articles. Among the top PWV contributors, WhisperToMe(#8) is highest ranked by number of edits: he is #13 on that list, having edited 74,000 times on 27,000 articles.
...we found essentially no correlation between [number of] views and [number of] edits
The Signpost has more coverage