“Area libraries increasing security to combat rising thefts” is the headline for the April 23, 2011, article posted by the Dayton Daily News. But the question that comes to the ALA Library is “what is a ‘typical’ loss rate?”

There is no “typical” rate of loss for several reasons. Inventories, unless done in conjunction with another operation, such as catalog conversion or adding electronic security tags, are expensive and not undertaken frequently. Libraries that sample the collection use different methods, which may not be comparable. Only a few states collect the information as part of the annual library statistics. Thus, there is no national figure to describe the problem.

Individuals and individual libraries have conducted surveys over the years, but without any regularity or periodicity. Circulation, Interlibrary Loan, Patron Use, and Collection Management: A Handbook for Library Management, by David F. Kohl (Santa Barbara, Calif: ABC-CLIO, 1986) reports a range of research studies relating to loss rates.

Based on the studies reported, there is a loss of .15% to .5% per year; or overall loss rates of 4–8% when an inventory, or inventory sample, is conducted periodically.

In her 1998 book Managing Overdues (New York: Neal-Schuman), Patsy J. Hansel makes some leaps from surveys she did to posit a national “overdue rate” of .7% pre-automation and .4% for post-automation to suggest a national loss of 6.28 million items, or $125.6 million at a rate of $20 per book. The number of items was based on 1994 NCES circulation data—and the replacement rate would be far higher today.

Why do books go missing? Some are simply misshelved and will eventually resurface; others are lost by library users, with the lost item fees paid. Sadly, many are stolen, though electronic detection systems do minimize that risk.

As the Dayton article reports, different parts of a collection experience different loss rates. Audiovisual material and test preparation books have higher loss rates than those in the general book collection—except for travel guides, which one writer suggests have “shortened” lives.

We’ve collected a selection of articles describing methods to measure loss rate, as well as tips for locating the misshelved books or instituting procedures to identify lost materials and determine whether to replace them or not.