The Zombie Stack Exchanges That Just Won't Die
In a recent blog article about the question "How Much of the Literature Goes Uncited?" I just found this question. The author argues that the answerdepends on the observation period and the universe of observation, so there is no simple answer. There should be, however, typical answers to typical library scenarios, studies in library and information science, or guidelines for collection development.
Jakob
The 80/20 rule generally applies here: 80% of the library's collection is used 20% of the time, and vice versa. It can vary depending on the focus of the collection and the relevance to user needs. A general research library is more likely to collect on a "just in case" model, whereas a more focused specialized library is going to collect a narrower range of "just in time" material, and probably weed more often so that the remaining materials are the ones that are being used most often already.