The Library places a limit on the number of times a book may be renewed for a couple of reasons. The policy encourages borrowers to return books that they are no longer actively using. Having more books on the Library's shelves increases the ability of borrowers to browse the collection and provides more immediate access to materials than our recall system provides. We can also ensure a controlled physical environment for our books, thus aiding in their preservation. As a result of periodic review of loan records, we have fewer missing books when borrowers leave the University.