Will you still need me, will you still read me…? Patron-driven acquisition books' circulation advantage long-term and post-pilot

Use-driven and needs-driven acquisitions methods, such as Patron-Driven Acquisitions (PDA) programs for print materials, have become widely established in academic libraries. Though largely favorable, much of the relevant published research has, of necessity, reported the results of pilot and recently adopted programs. These studies have reported that patron-requested and -accessed materials tend to produce more usage than materials acquired via traditional methods, but recent research has suggested that some output measures may equalize with traditionally acquired materials' results over time. To address this potential issue, the current study will explore whether the circulation advantage of one academic library's PDA books has persisted over the long term when compared to the performances of subject-matched samples of librarians' firm orders and of approval plan selections. Additionally, the study will test whether the higher circulation performance of PDA books persists after a pilot interval. Finally, to address colleagues' objections that early circulation counts offer an inadequate measure for patron use over the longer term, especially for books in the arts and humanities, this study will repeat its analyses for circulations plus renewals. To obtain a clearer understanding of the potential effects of books' acquisition modes, this study will include books' broad disciplines, prices paid for the books, and time spent as part of the collection as control variables.