Are first-circulation patterns for monographs in the humanities different from the sciences?

How many monographs acquired in a particular year circulate in that year? What percentage have their first circulation each successive year? Does the pattern differ for different broad subject areas, i.e., humanities, the sciences, and the social sciences? This article tests the assumption that the first-circulation pattern differs by subject. We conclude that the pattern does not differ. The finding is important for decisions about off-site storage, assessing collection development, maintaining departmental libraries, etc. Regardless of subject, if a book has not circulated at least once within a few years after acquisition, it is unlikely to find its reader.