The University of California System has issued its 2009 Accountability Report, "provid[ing] the first comprehensive assessment of the University’s progress in meeting key teaching, research and public service goals across its 10 campuses."
This report describes how the UC libraries rate on a variety of performance measures. It concludes that:
The University of California libraries provide access to the world’s knowledge for the UC campuses and the communities they serve. In so doing, they directly support UC’s missions of teaching, research and public service. …
These indicators measure library size, impact and vitality. They demonstrate that the University of California has an information resource collection that is truly unmatched in the United States. UC students and faculty are able to take advantage of these resources from any campus in the system, and they do so in larger numbers every year.