Self-organized human behavioral patterns in book loans from a library

Abstract In a university library, students and faculty visit frequently to borrow books. The interactions between people and books indicate their current reading patterns. We analyze loan data on books in a university library, observing two aspects of book-borrowing behavior: returning them before the due date, and after it. We observe a steady distribution in the book-returning probability, modulated by weekly periodicity. After the due date, the probability distribution of the holding time shows power law behavior. The periodicity and power law were observed, regardless of borrowers being undergraduate students, graduate students, or faculty. We also observe power law behavior in the probability distribution for inter-event distribution between book loans. We can explain the power law relationship for the holding time of a book as a queuing model of job priorities.