Gail P. Clement has published "American ETD Dissemination in the Age of Open Access: ProQuest, NoQuest, or Allowing Student Choice" in College & Research Libraries News.
Here's an excerpt:
A stark incongruity in the treatment of academic scholarship persists on many U.S. campuses today. Faculty authors are generally free to publish in whatever vehicle suits their needs and goals, while also expected (or mandated) to deposit their works in the open access university repository. By contrast, graduate students typically must send their scholarship to a single commercial publisher for toll-access, while also required to submit their works to the university repository.