"Contributions to the Encyclopedia are normally solicited by invitation from a member of the Editorial Board. However, qualified potential contributors may send to the Principal Editor or an appropriate member of the Editorial Board a proposal to write on an Encyclopedia topic, along with a curriculum vitae."
"By qualified, we mean those persons with accredited Ph.D.s in Philosophy (or a related discipline) who have published refereed works on the topic of the proposed entry..."
Also perhaps http://plato.stanford.edu/info.html#copyright .
I don't know how much non-cs academics think about copyright and licensing, but as most accomplished academics are authors, I am guessing it may matter to them that they keep ownership.
"Copyright Notice. Authors contributing an entry or entries to the Stanford Encyclopedia of Philosophy, except as provided herein, retain the copyright to their entry or entries. By contributing an entry or entries, authors grant to the Metaphysics Research Lab at Stanford University an exclusive license to publish their entry or entries..."
This is just one facet of course. I'm sure there are many other factors such as possibly the stature of the Stanford lab, and particular personal relationships and technical skill of those involved, good timing, etc. I'd be very curious to hear from those with personal knowledge of the details.
One hint may be in http://plato.stanford.edu/info.html#policies
"Contributions to the Encyclopedia are normally solicited by invitation from a member of the Editorial Board. However, qualified potential contributors may send to the Principal Editor or an appropriate member of the Editorial Board a proposal to write on an Encyclopedia topic, along with a curriculum vitae." "By qualified, we mean those persons with accredited Ph.D.s in Philosophy (or a related discipline) who have published refereed works on the topic of the proposed entry..."
Also perhaps http://plato.stanford.edu/info.html#copyright . I don't know how much non-cs academics think about copyright and licensing, but as most accomplished academics are authors, I am guessing it may matter to them that they keep ownership.
"Copyright Notice. Authors contributing an entry or entries to the Stanford Encyclopedia of Philosophy, except as provided herein, retain the copyright to their entry or entries. By contributing an entry or entries, authors grant to the Metaphysics Research Lab at Stanford University an exclusive license to publish their entry or entries..."
This is just one facet of course. I'm sure there are many other factors such as possibly the stature of the Stanford lab, and particular personal relationships and technical skill of those involved, good timing, etc. I'd be very curious to hear from those with personal knowledge of the details.