A recent article in the J of Academic Librarianship:
Maybe our user services librarians would be interested in a similar study at RU? 
"Conclusion
The
results of this study suggest that students who utilize academic
libraries within their first year have higher cumulative grade point
averages and retention, on average, than their peers. Additionally,
students' use of libraries in particular areas was positively associated
with their cumulative GPAs and retention. While the overall effect of
library use was small in all library use areas, the results of this
study point toward the potential importance of academic libraries that,
alongside other programs within the greater institutional context, can
help to promote college students' success."
